Re: [time-nuts] WWVB antennas
Claims on antenna efficiency at these frequencies are fairly meaningless (as always) in that a normal antenna efficiency would be less than 1% !! Alan G3NYK - Original Message - From: JIM FARLEY jimfar...@att.net To: t...@patoka.org; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, February 22, 2014 4:28 PM Subject: Re: [time-nuts] WWVB antennas Google 'fractal antenna'. Fractal Antennas are a relatively recent (late 1980's to mid-1990's) discovery/invention. I have read that they are approximately 20% more efficient than normal antennas. Jim, KG4FXV From: d0ct0r t...@patoka.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, February 22, 2014 12:54 AM Subject: Re: [time-nuts] WWVB antennas I am impressed by Casio engineers who created tiny antenna for my wrist watch. I don't know how, but that Pathfinder able to catch and decode 60 khz wwvb in noisy city environment. And it did even better when i was 500 km north ! :40, Alexander Pummer wrote: here are the other 60kHz transmitters: http://www.ka7oei.com/wwvb_antenna.html U.S. based WWVB transmitter. As described, it could also be used for theUK-based 60 kHz MSF http://en.wikipedia.org/wiki/Time_from_NPL MSF signal formerly the Rugby clock* *and the Japanese 60 kHz JJY http://en.wikipedia.org/wiki/JJY_ _our fiend in Australia most likely*_ _*receive the JapaneseWWVB 73 KJ6HUN Alex _*//*_ On 2/21/2014 12:21 PM, Robert Roehrig wrote: John Forster said: WWVB is hard to detect w/ a 3-foot diameter HP shielded loop w/ integral preamp 2 stages of mechanical filters. (HP 117A). The other half of the time it was undetectable. Paul S uses a loop that is much larger. I am near Chicago and I have 2 60 kHz antennas. One is a ferrite rod type and the other a 5 foot diameter loop. Both are tuned and feed identical 2 transistor preamp. The loop does work better. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] frequency comparator reading question
These units multiply the frequency delta and the phase change quoted is probably 10^n times the actual difference. The output is f + n*delta(f) I have but do not use a Montronix 100-7 (before the Fluke purchase) Alan G3NYK - Original Message - From: Bill Hawkins b...@iaxs.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Thursday, February 27, 2014 5:55 PM Subject: Re: [time-nuts] frequency comparator reading question The question can't be answered without knowing what the range switch does. In my experience, the cycle that is divided into 360 degrees is the period of the input signal regardless of the range switch. You don't say, but the usual GPSDO produces a 10 MHz signal, unless it's for a telco application. If the phase meter goes through one cycle in a second there is a one cps difference between the signals. One cycle at 10 MHz is one part in 10E7. One cycle in a kilohertz is 1 part in 1000. 1 cycle in 100 seconds for 10 MHz is one part in 10E9 Does the time for a phase rotation vary with the range switch? Bill Hawkins -Original Message- From: Bob Camp Sent: Wednesday, February 26, 2014 9:16 PM Not having one here, about all I can guess is that there are 360 degrees in a cycle. If it's going through 360 degrees in 10 seconds it's 0.1 Hz off at what ever point it's comparing. If it takes 100 seconds that's 0.01 Hz. Yes I get this pesky decimal point stuff wrong from time to time ... Bob On Feb 26, 2014, at 9:19 PM, Paul A. Cianciolo pa...@snet.net wrote: I have a Fluke montronics frequency comparator. It has 2 inputs, one from my GPS and one from my DUT. After a given oscillator is warmed up, I can read the meter in parts 10 -X There are 2 meters, One for phase 0 to 360 degrees, and one for part to the -nth In the 10-9th position on the selector switch the a given oscillator will show a 0 to 360 degrees travel lets say in 1 second. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Phase noise and geomagnetism
Hi Antonio you must remember the static geomagnetic field is around 50,000nT and the biggest Solar induced events are around 500nT so the effect might be difficut to detect as events of this size are not very common. More common events are in the 100 to 200nT range. Alan G3NYK - Original Message - From: iov...@inwind.it To: time-nuts@febo.com Sent: Monday, April 28, 2014 10:18 PM Subject: [time-nuts] Phase noise and geomagnetism As our geomagnetic field gets quite noisy during geomagnetic storms (which are connected to solar activity), I was wondering if this could affect phase noise of oscillators. I see that theoretically it could. Has anybody ever measured phase noise increments which could be explained this way?Antonio I8IOV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Diodes as temperature sensors
Simple temperature sensors use the static diode characteristic, but a more accurate method is to use the slope of the characteristic, this is independent of individual diode parameters, though requires a little it more electronics to display. There are many papers on this back in the 1960/70s. Alan G3NYK From: Hal Murray hmur...@megapathdsl.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Cc: hmur...@megapathdsl.net Sent: Monday, 21 July 2014, 4:58 Subject: Re: [time-nuts] Diodes as temperature sensors alw.k...@gmail.com said: Apparently, the forward biased silicon diode was temperature sensitive enough that a small D.C. amplifier could drive a meter to read-out with reasonable accuracy. Well, maybe not accurate by Time-nut standards but close enough for its intended purpose. I think that mechanism is widely used for silicon temperature sensors. There is one (or more) on most modern CPU chips as well as special temperature measuring chips such as the Maxim/Dallas DS18B20 and DS18S20. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] temperature sensor
er not boiling watersteam. Water's boiling point is affected by the dissolved gasses and other contaminants. Alan G3NYK - Original Message - From: Bill Dailey docdai...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, July 21, 2014 5:43 PM Subject: Re: [time-nuts] temperature sensor Ice water and boiling water coupled with altitude will give you two points. Sent from mobile On Jul 21, 2014, at 10:12 AM, Attila Kinali att...@kinali.ch wrote: On Mon, 21 Jul 2014 04:39:51 -0700 Alexander Pummer alex...@ieee.org wrote: NTC are not that very stable, they are amorphous material winch could recrystallize slowly and therefore change it's electrical behavior , PT100 style is more reliable since it is pure metal How long is the time constant for NTCs? I guess, it wouldn't matter for most of the measurements we do, as NTCs need to be calibrated before precision measurements anyways. Unless one measures over several months, or years. But on this timescales, i wouldn't really trust an off the shelf PT100 either. Not unless i measure its stability For use in GPSDOs and OCXOs, i guess it doesn't really matter, as long as the NTC stays within spec. There an external loop corrects for the variation/drift of the measurement. While we are at it: what is a good way to calibrate/characterize temperature sensors that is available to hobbyists? Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] temperature sensor
Yes but water can be superheated too if there are no nucleation points for bubbles to form and like super-cooling this can amount to a couple of deg C in a very clean container. However the vapour cannot be superheated without increasing the pressure .as in a steam engine, or autoclave. I may not be as accurate as temperature nuts would like but unless you are very sure of your conditions it is probably more reliable. I notice the wiki on temperature scales doesn't include boiling water (or steam) these days, but if does say is 17mK low of an exact 100 :-)) http://en.wikipedia.org/wiki/Temperature_scales#International_temperature_scale_of_1990 I note it doesnt actually say where you place the sensor :-)) Alan G3NYK - Original Message - From: Brooke Clarke bro...@pacific.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, July 21, 2014 9:11 PM Subject: Re: [time-nuts] temperature sensor Hi: The temperature of steam can be anything above boiling water. http://en.wikipedia.org/wiki/Steam Super heating of steam was common railroad practice. Boiling pure water will get rid of any trapped gases quickly. In fact this is the recommended thing to do to tap water before using it for freshly cut roses. Of course you need to let the water cool before putting them into it. Removing the trapped oxygen makes them last longer. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Alan Melia wrote: er not boiling watersteam. Water's boiling point is affected by the dissolved gasses and other contaminants. Alan G3NYK - Original Message - From: Bill Dailey docdai...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, July 21, 2014 5:43 PM Subject: Re: [time-nuts] temperature sensor Ice water and boiling water coupled with altitude will give you two points. Sent from mobile On Jul 21, 2014, at 10:12 AM, Attila Kinali att...@kinali.ch wrote: On Mon, 21 Jul 2014 04:39:51 -0700 Alexander Pummer alex...@ieee.org wrote: NTC are not that very stable, they are amorphous material winch could recrystallize slowly and therefore change it's electrical behavior , PT100 style is more reliable since it is pure metal How long is the time constant for NTCs? I guess, it wouldn't matter for most of the measurements we do, as NTCs need to be calibrated before precision measurements anyways. Unless one measures over several months, or years. But on this timescales, i wouldn't really trust an off the shelf PT100 either. Not unless i measure its stability For use in GPSDOs and OCXOs, i guess it doesn't really matter, as long as the NTC stays within spec. There an external loop corrects for the variation/drift of the measurement. While we are at it: what is a good way to calibrate/characterize temperature sensors that is available to hobbyists? Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] fast switching quiet synthesizer
Jim I am not sure if this will meet your requirement for hygene but google Trinity Power Inc (Bob Yarbrough) he has a unit that was featured in EDN some time around a year ago. I doesnt switch fast enough at present but that could be altered. the problem might be that I think it is a PLL Rather than a DDS. But might be worth a look I know the PTS I have a couple of earlier Wavetek- Rockland units ...one TTL and one GPIB also an Adret 201 which uses the same technique. Alan G3NYK - Original Message - From: Jim Lux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, October 07, 2014 6:02 PM Subject: [time-nuts] fast switching quiet synthesizer At work, I'm putting together a multichannel stepped frequency CW radar breadboard, and I'm looking for something to serve as a source that I can step quickly. I'm looking at stepping every millisecond or so. Right now, I use a Ardunino type microcontroller driving a serial DAC driving a VCO, but that's a bit wonky and noisy, although it's easy to get the step timing right on. The spectral purity is, shall we say, downright ugly. Since I'm going to be doing precision ranging with this, the spectral purity has to be reasonably good (not 1E-15 at 1000 seconds good, fortunately).. I was thinking about a PTS synthesizers (beloved of time-nuts for all kinds of reason), and they're nice because they are quiet, and switch really fast (microseconds). However, they all seem to have BCD or GPIB interfaces (only). Sure, I can code up something on an Arduino or other microcontroller to drive the BCD on the PTS, but maybe there's something else out there that might work as well? And is already off the shelf. I could hook a Prologix on the back of a PTS with GPIB, and hit it over the ethernet, but I'm not sure I'd be able to get the steps to occur when I want them (ethernet and determinism do not go well together). Maybe some DDS in a box product? That will take my nice clean 10 MHz reference? Ultimately, I'm looking at output frequencies in single digit GHz, but something that can be mixed/multiplied up will work just fine. I'm looking for something that is off the shelf-ey as much as possible. Using surplus gear is ok, because I really only need 3 or 4 channels and that might be scroungeable, but spending hours wiring up weird adapters or locating connectors that haven't been made since 1943 is something I'd like to avoid. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] fast switching quiet synthesizer
Hi Don, Jim, that is the one I was refering to, It has a VCO as the source (all part of the AD4351) but I think your description of the unit is more accurate that mine. Contact him directly he is keen to contact new areas and hobbyists. There are two units one is a source with 4 output levels, I believe he sells that on eBay at $280 but direct contact may get you a better deal. There is a version with a calibrated attenuator but this has FM capability which adds to the VCO control and may not be good for PN. I think this sells for $340. Robert Yarbrough rob...@rf-consultant.com (blame me for airing his ID :-)) ) Alan G3NYK - Original Message - From: Don Latham d...@montana.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, October 07, 2014 9:19 PM Subject: Re: [time-nuts] fast switching quiet synthesizer I have two versions of the ADF4351 dds. One is the AD eval board, and the other the TPI synthesizer (http://www.rf-consultant.com/calibrated-signal-generator/) at $280 that might do the job. The latter device performs well. It will be as good as the 4351, I think. It has a programmable attenuator. A good price. Requires a Healthy! USB port. Don Magnus Danielson You should be able to use DDS test-boards and by timing your last write, you should be able to time the frequency jump. The STEL-1173 takes 6 bytes, but writing the last one latches all 6 bytes over to a single 48 bit word. I expect that other DDSes have the same distinct transfer-phase if you only look in the datasheet for the details. Some of the modern DDSes can take 10 MHz directly and step it up internally before hitting the DDS core, but it may be that you need to synthesize a higher clock from the 10 MHz first. Cheers, Magnus On 10/07/2014 07:02 PM, Jim Lux wrote: At work, I'm putting together a multichannel stepped frequency CW radar breadboard, and I'm looking for something to serve as a source that I can step quickly. I'm looking at stepping every millisecond or so. Right now, I use a Ardunino type microcontroller driving a serial DAC driving a VCO, but that's a bit wonky and noisy, although it's easy to get the step timing right on. The spectral purity is, shall we say, downright ugly. Since I'm going to be doing precision ranging with this, the spectral purity has to be reasonably good (not 1E-15 at 1000 seconds good, fortunately).. I was thinking about a PTS synthesizers (beloved of time-nuts for all kinds of reason), and they're nice because they are quiet, and switch really fast (microseconds). However, they all seem to have BCD or GPIB interfaces (only). Sure, I can code up something on an Arduino or other microcontroller to drive the BCD on the PTS, but maybe there's something else out there that might work as well? And is already off the shelf. I could hook a Prologix on the back of a PTS with GPIB, and hit it over the ethernet, but I'm not sure I'd be able to get the steps to occur when I want them (ethernet and determinism do not go well together). Maybe some DDS in a box product? That will take my nice clean 10 MHz reference? Ultimately, I'm looking at output frequencies in single digit GHz, but something that can be mixed/multiplied up will work just fine. I'm looking for something that is off the shelf-ey as much as possible. Using surplus gear is ok, because I really only need 3 or 4 channels and that might be scroungeable, but spending hours wiring up weird adapters or locating connectors that haven't been made since 1943 is something I'd like to avoid. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] fast switching quiet synthesizer
Jim, Bob Yarbrough's built units do 50 to 4400MHz, +10dBm and input for external 10MHz ref signals, though has an internal 10MHz TCXO. It sounds worth a try if it can be programmed to step fast enough, min step size is 1kHz (from memory). Alan G3NYK - Original Message - From: Jim Lux jim...@earthlink.net To: time-nuts@febo.com Sent: Wednesday, October 08, 2014 12:36 AM Subject: Re: [time-nuts] fast switching quiet synthesizer On 10/7/14, 10:32 AM, Magnus Danielson wrote: You should be able to use DDS test-boards and by timing your last write, you should be able to time the frequency jump. The STEL-1173 takes 6 bytes, but writing the last one latches all 6 bytes over to a single 48 bit word. I expect that other DDSes have the same distinct transfer-phase if you only look in the datasheet for the details. Yes, virtually all of them have a load input of some form (I'm familiar with the AD98xx and AD99xx ones, and they certainly do). What I'd really like, though is something at a slightly higher level of integration (for which I am willing to pay.. it's a time vs money thing). Does someone sell a DDS in a box with connectors, etc. I need a tuning range, for now, of around 3.1 to 3.4 GHz, so any of the 1 GHz DDSes can generate something that I could mix up with a 2.8-3 GHz LO (which I have), although I'd have to be careful about images. Or I can run the few hundred MHz out of the DDS into a doubler/tripler, then mix up. Some of the modern DDSes can take 10 MHz directly and step it up internally before hitting the DDS core, but it may be that you need to synthesize a higher clock from the 10 MHz first. Not a problem, I think I have a 10 in to 100 MHz out set of bricks from Wenzel (x5 and x2) from a previous project ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Said I read through the description carefully .I suggest you request a refund from eBay for their use of incompetant computer translation which fails to recognise English technical words and phases, so blocking your paid for posting. The trigger can only be due to a stupid word selection in translation. I can see no English (or American :-)) ) word that could be responsible. Alan G3NYK - Original Message - From: S. Jackson via time-nuts time-nuts@febo.com To: sylva...@netcourrier.com; time-nuts@febo.com Sent: Saturday, October 18, 2014 9:02 PM Subject: Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt. Hello Mr Richard, that's a first! While I lived in Germany for almost 2 decades, I am not sure what other connection the listing could have to Nazi propaganda??! If anyone has any suggestions how to reword the listing I would love to hear them. For now, can you use a proxy server to get access to the site? Don't we just love internet censorship. Bye, Said In a message dated 10/18/2014 12:35:27 Pacific Daylight Time: Mr Jackson, May I suggest you rewrite the eBay description for the LTE-Lite. As it stands, it triggers the anti-nazi filters that block some items from being displayed in France possibly some other countries (at least Germany and Austria): Unfortunately, access to this particular item has been blocked due to legal restrictions in some countries. We are blocking your viewing in an effort to prevent restricted items from being displayed. Regrettably, in some cases, we may prevent users from accessing items that are not within the scope of said restrictions because of limitations of existing technology. Please accept our apologies for any inconvenience this may cause, and we hope you may find other items of interest on eBay. Best regards, Sylvain RICHARD Le 18/10/2014 19:58, David J Taylor a écrit : See http://www.ebay.com/itm/LTE-Lite-GPSDO-Evaluation-Kit-with-20MHz-TCXO-/171504586548 Ships World wide for $10 US Regards, John K1AE === Well, no. If I look at that entry from the UK it says: $24.75 USPS Priority Mail International Small Flat Rate Box so it's not US $10 worldwide. David ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] BBC TV program Click has material about GPS jammingand e Loran
The politics of this system are a bit dubious as are the claims on accuracy and freedon from jamming. But it does give us another off-air frequency standard. Alan G3NYK - Original Message - From: Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, November 01, 2014 3:07 PM Subject: [time-nuts] BBC TV program Click has material about GPS jammingand e Loran Click is a short TV program produced by the BBC about tech related things. Anyway, the issue I see today (1/11/2014) http://www.bbc.co.uk/programmes/b04p21jv had a bit about GPS failure, GPS jamming, and use of eLORAN as a backup. *Hopefully* you can see it on the BBC iPlayer if interested, although I am not sure if those outside the UK can see it - you might need to use a proxy server in the UK, since I have no idea if they block access based on IP. Also more on the BBC in the last 24 hours or so about this. http://www.bbc.co.uk/news/science-environment-29758872 Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Digital temperature compensation
Mmmm yes you can see the equation evaluation starting to rise in your Warmer plot, as Mark says, which will make a nonsense of the formula if your summer temps get above 28. Why not a table and then interpolate between the table data points?. You might have more points where the changes are greater. The colder plot looks cubic maybe for a crystal made for 20 deg C ?? But depending on the oscillator electronics you may have component tempcos affecting the frequency as well? I suspect the turnover at 21deg C should be a smooth curve not as your formula predicts. Which suggests that you have too too high an order of polynomial I think, but you may not get a good fit with a cubic if other effects are present. Alan G3NYK - Original Message - From: Dan Drown dan-timen...@drown.org To: time-nuts@febo.com Sent: Saturday, November 01, 2014 10:07 PM Subject: Re: [time-nuts] Digital temperature compensation I gave zunzun a try and the one with the lowest root mean squared error was: f(x) = a( x**0.5) + b( x ) + c( sin(x) ) + d( cos(x) ) It got 0.202 RMSE, so I guess I'll stick with my original function as it seems to be closer to what I expect will happen at colder/hotter temps. You have a good point about temperatures outside my data samples. Once it gets hot again in the summertime, I'm sure I'll have to re-evaluate this. Quoting Mark Sims hol...@hotmail.com: You could try submitting your data to zunzun.com It will fit it to around 40,000 different curves and find the best ones. Beware that with all curve fitting formulas, once your live data starts to wander out of the range of your original curve fit data, things can go rather badly... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Quad Driven Mixer 5 to 10 MHz Doubler Atricle
As a subscriber to QEX I saw this article but thought that the bi-phase rectifier was a lot easier and has be well characterised by the time-nuts experts. Now it has shown up here I would be interested to hear from those experimenting how badly the NE602 performs compared with a passive DBM for nuts-style applications :-)) I have a pile of kit with 5MHz VCXOs (Racal and Marconi) including an excellent GPSDO by Rapco. Alan G3NYK - Original Message - From: Dave Daniel kc0...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, November 12, 2014 10:36 PM Subject: Re: [time-nuts] Quad Driven Mixer 5 to 10 MHz Doubler Atricle I believe I have a PDF copy of the article if anyone wants it. It's about 1.3 MB in size. DaveD On 11/12/2014 2:36 PM, Don Latham wrote: It's interesting. I took the hint, and tried sin(a)*sin(b) expand and set b=a+pi/2. fun fun fun. All that's needed in theory is a mixer and a pi/2 phase shifter at 5 MHz. Probably a bunch of other stuff because of real parts :-) Minicircuits will sell you one, packaged, for about 50 rasbucknicks. Don Dave M I am able to download the files associated with the article, but not the article itself. Guess I need to be a paying member to get the article. The only files in the download are the XLS file for calculating the filter values, and the parts list. It's at http://www.arrl.org/qexfiles in the year 2011 listings, filename 3x11_Roos.zip titled Converting a Vintage 5 MHz Frequency Standard to 10 MHz with a Low Spurious Frequency Doubler Dave M John C. Roos via time-nuts wrote: Several list members contacted me expressing interest in the article. None of them were able to download much or anything from the ARRL QEX web site. That includes me and other ARRL members. I am working the issue with one call to ARRL so far today. I will contact Larry Wolfgang at ARRL and see what Ican bust loose. So hang in there. It is a cute technique, not originated by me, but useful. Right now I have to get the ARRL FMT done first. -73 john c roos k6iql ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Division Circuit
Isn't the 10i/p gate to do the divide by N+1?? not just to avoid an all zeros switch on which does not need all 10 stages fed back if all you want is an N stage ring counter?? Alan G3NYK - Original Message - From: Tim Shoppa tsho...@gmail.com To: Said Jackson saidj...@aol.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, November 14, 2014 9:53 PM Subject: Re: [time-nuts] Division Circuit Yes! I did find a patent that illustrated the exact same feedback circuit as in the EE times article. But most self-decoding ring counters in mass-produced applications use simpler lower propagation-delay gate arrangements to ensure the counter self-corrects any defective sequences. e.g. look at how the CD4017 does not use a 10 input NAND gate!!! Tim N3QE On Fri, Nov 14, 2014 at 4:39 PM, Said Jackson via time-nuts time-nuts@febo.com wrote: The premise of higher than normal click speed is false in the article too because the complex NOR gate is slow with that many inputs, and its tpd needs to be added to the Tsu and Tco of the flip flop chains, as well as the pcb propagation delays through the worst case trace.. It would have been faster to simply use a single reset RC delay to reset all FF asynchronously while only setting one FF at the same time during power-on. That would remove the Nor gate delay from the max speed calculation.. Sent From iPhone On Nov 14, 2014, at 12:13, Don Latham d...@montana.com wrote: Thanks. You reminded me of the time when design ideas really had content. No more, I'm afraid... Don Azelio Boriani No need to digitize, the article is available here: http://www.edn.com/design/test-and-measurement/4347165/Circuit-divides-frequency-by-N-1 or here (in .PDF): ftp://ztchs.p.lodz.pl/PRP/PRP_2006_2007/71102di.pdf On Fri, Nov 14, 2014 at 8:02 AM, Perry Sandeen via time-nuts time-nuts@febo.com wrote: List, I’ve digitized and edited an article titled* Circuit DividesFrequency by N+1 by Bert Erickson, Fayetteville, NY from EDN 7/11/2002*. Essentially, this circuit is expandable and allows for adivision by any number plus one. Anyone who wants a PDF copy please send me an original emailoff list. Regards, Perrier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 10811
Yes below about 4v is the only place where you get the real Zener effect, as you go above 5v it becomes Avalanche Breakdown. The trick is zener effect has a negative tempco and avalanche a positive one (I thinkthey are opposite senses anyway :-)) ) the result is a regulator diode (zenerso called) specced at around 5 to 5.5 volts has a near zero overall tempco. Alan G3NYK - Original Message - From: Brooke Clarke bro...@pacific.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, November 18, 2014 10:31 PM Subject: Re: [time-nuts] 10811 Hi Rick: When working on Tunnel Diode amplifiers we used (AFAICR) 5.1 V Zener diodes to stabilize the lower voltage that drive the diode. 5.1V was supposed to have excellent temperature characteristics in terms of repeatability (don't remember if low noise was part of the selection criteria). http://www.prc68.com/I/Aertech.shtml#TDA The boards with the terminals have the Zener and a custom compensation network using both Veco (spelling?) (-TC) and Balco (+TC) and fixed resistors so that the gain stays constant over mil temperature ranges. Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Richard (Rick) Karlquist wrote: On 11/17/2014 5:54 PM, Bert Kehren via time-nuts wrote: I ground one side of the tuning diode and use the 2 to 12 V as the external OCXO for my FRK's along with increasing the time constant. I have not verified it but I think removing the zener Voltage should also improve ADEV. Bert Kehren The choice for the Zener diode came from my old boss at HP, who was very knowledgeable about using discrete zener diodes as low noise references. According to him, this particular part number has very respectable noise. This is just something you have to know experientially, there is no theory of zener noise AFAIK. You might try measuring the noise of the 6.2V reference voltage directly at baseband, and then multiplying by the 1 Hz/volt sensitivity. Let us know your results. Rick Karlquist N6RK (Now retired from HP/Agilent/Keysight) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 57600 baud rate with Basic???
Hi Corby I havent checked Liberty Basic but I believe it does support 57.6kBd.. I have definitely used this speed on PowerBasic for Windows which is a latter day upgrade of Borland stable, I believe, but very is very different to GWBasic or QBasic (which is also limited to 9600Bd) and is much more like MS Visual Basic which also support 57.6kBd but with totally abysmal support on comms interfacing. That was why I moved to PBfW which has a good working example that could probably be hacked for your purposes. Their API is a lot easier to understand too. I hope that helps I am sure other will have their thoughts. Moving code from GWBasic to another flavour just to chnge the speed might not be completely trivial :-)) Alan G3NYK - Original Message - From: cdel...@juno.com To: time-nuts@febo.com Sent: Tuesday, October 09, 2012 6:44 PM Subject: [time-nuts] 57600 baud rate with Basic??? Hi, I'm currently using a GWBasic program at 9600 Baud to get 1 second T.I. data (12 digits) from an SR620 counter, display the reading , put the reading into a file, name the file sequentialy, and either save or delete the file via a function key. I'm switching to a new counter that outputs at 57600 Baud (9 digits). Is there a version of Basic I can use that would support that 57600 Baud rate? Thanks, Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/507462c97549762c919e3st02duc ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 57600 baud rate with Basic???
Dinosaurs ruled the world for millions of years, and morphed into creatures that ruled the air until very recently .bit longer than dotcomms ...They were very successfull :-)) Alan G3NYK - Original Message - From: shali...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, October 09, 2012 7:55 PM Subject: Re: [time-nuts] 57600 baud rate with Basic??? I am pretty sure good old Visual Basic Pro version 6.0 (and newer) supports to 115kb. GW Basic officially makes you a ... Didier KO4BB Sent from my Droid Razr 4G LTE wireless tracker. -Original Message- From: cdel...@juno.com To: time-nuts@febo.com Sent: Tue, 09 Oct 2012 12:46 PM Subject: [time-nuts] 57600 baud rate with Basic??? Hi, I'm currently using a GWBasic program at 9600 Baud to get 1 second T.I. data (12 digits) from an SR620 counter, display the reading , put the reading into a file, name the file sequentialy, and either save or delete the file via a function key. I'm switching to a new counter that outputs at 57600 Baud (9 digits). Is there a version of Basic I can use that would support that 57600 Baud rate? Thanks, Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/507462c97549762c919e3st02duc ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 10811 Tuning Diode
Rick, Adrian, I think there are a number of possibly material related areas that could cause a varicap to go noisy but I have no experience of them First a reversed biased diode makes quite a good particle detector :-)) and remanent radioactive atoms in say the glass could cause localised avalanches. This would seem unlikely because it would affect a whole batch but possible. I also wonder what the effect of strain, crystaline dislocations etc might do to the very small current flowing in a very high impedance. These can lead to odd effects when they penetrate the junction.. It could just be an unfortunate sample. I suspect the level of noise current is way below any specified meaured value. Alan G3NYK - Original Message - From: Adrian rfn...@arcor.de To: rich...@karlquist.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, October 19, 2012 9:10 PM Subject: Re: [time-nuts] HP 10811 Tuning Diode I didn't notice any damage, nor was there a visibly bad solder joint. However, I couldn't reproduce the excess noise with a quick bench test at 30V / 100k neither. DC-wise there are a few microvolts only. Same with the SMD diode. Exept, when the original glass diode is exposed to light. With a LED Maglite, I got up to 50 mV (across 100 kOhm) out of it! But there is no light shining inside of a 10811, is there? I had first suspected a 0.1 ceramic cap, but that didn't cure the phase noise desease. The diode in the original circuit appeared to be heat sensitive, and the excess phase noise has gone away since I replaced the diode. The noise was clearly there, and it was also there using a test adapter and two lab power supplies. Adrian Rick Karlquist schrieb: I wonder if the glass case got a crack in it or if the kovar seal was failing. Maybe a failed solder joint (which gets fixed when you install the new diode). I've never heard of a noisy varactor before either. Rick ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Is it sensible to update every few seconds from NTPserver?
Hi Paul think synchronous data transmission where you cant detect enough signal to synchronise reliably via the bit edges received. Initially developed for LF (136kHz) where the ERP of amateur antennas is very low. Google Joe Taylor but not for his Nobel prize, who's original interest was Moonbounce communication. He has now generated modes for LF too. Alan G3NYK - Original Message - From: paul swed paulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, November 07, 2012 10:11 PM Subject: Re: [time-nuts] Is it sensible to update every few seconds from NTPserver? Interesting I am unaware of any amateur service requiring that tight of a timing relationship. At least modern PC clocks do not drift that badly in a few minutes. So it is pretty odd. Without further detail I am at a loss for why you need to do that. Maybe he is tinkering with spreadspectrum? Regards Paul On Wed, Nov 7, 2012 at 5:04 PM, David davidwh...@gmail.com wrote: Some Windows NTP clients like Tardis can calculate and implement a clock frequency adjustment instead of stepping the clock if the time adjustment is below a specified limit. If he was using an application that was upset by the time being stepped, then that might allow less frequent updates. If he is polling that often to maintain accurate time, then I would assume he is using a local known to be accurate NTP server. There are Windows NTP clients which will synchronize to GPS PPS time. That should be better than stock hardware and Windows can handle anyway. Something like a Garmin GPS18 is specified to be within 1uS and has a pulse to pulse jitter in the 10s of nanoseconds. On Wed, 7 Nov 2012 21:41:36 +, David Kirkby david.kir...@onetel.net wrote: Someone at my radio club uses some mode of operation where accurate time is required. He said the standard Windoze clock does not keep sufficiently accurate, so he has software which updates from an NTP server every 4 seconds or so. It's not exactly a denial of service (DOS) attack, but seems almost close to it in NTP terms to me. I can't really believe updating every few seconds is sensible myself, but he assures me it works very well. (I'm rather hoping it does not use a stratum 1 server!) I'm sure someone will say if you want accurate time on a PC, to use some combination of GPS, rubidium or OCXO with a 1 pps pulse and a serial port on a FreeBSD or similar computer. But that's probably not practical if your software only works on Windoze. Any comments? Dave, G8WRB. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best phase detector / mixer for 100MHz?
Hi Anders, isn't this format exactly what is inside the high level mixers (spec'e +17dBm) from Minicircuits? Alan G3NYK - Original Message - From: Anders Time anderst...@gmail.com To: time-nuts@febo.com Sent: Friday, November 23, 2012 3:42 PM Subject: [time-nuts] Best phase detector / mixer for 100MHz? I have been using an minicircuits mixer as a phase detector for measuring low frequency(5-10MHz) and it is usually good enough. But when I want to measure 100MHz the sensitivity of the mixer decreases a lot, so when I want to measure some really low noise 100MHz(Pascall -178dBc floor with 18dBm out) oscillators the sensitivity is not good enough. I read in an old article by Walls, Stein et al(Design considerations in state-of-the-art signal processing and phase noise measurement system) that one can use two diodes in series in the double balanced mixer to increase the sensitivity. I tried this with some standard 1n5711 Schottky and the sensitivity is now 1V/rad, but is there a easier way to do this? /Anders ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Best phase detector / mixer for 100MHz?
Not unreasonable Bruce..no free lunches etc. :-)) Alan G3NYK - Original Message - From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, November 23, 2012 5:38 PM Subject: Re: [time-nuts] Best phase detector / mixer for 100MHz? NIST have shown (at least at 10MHz) that the high level mixers they tested are noisier than the ZRPD1. Bruce Alan Melia wrote: Hi Anders, isn't this format exactly what is inside the high level mixers (spec'e +17dBm) from Minicircuits? Alan G3NYK - Original Message - From: Anders Time anderst...@gmail.com To: time-nuts@febo.com Sent: Friday, November 23, 2012 3:42 PM Subject: [time-nuts] Best phase detector / mixer for 100MHz? I have been using an minicircuits mixer as a phase detector for measuring low frequency(5-10MHz) and it is usually good enough. But when I want to measure 100MHz the sensitivity of the mixer decreases a lot, so when I want to measure some really low noise 100MHz(Pascall -178dBc floor with 18dBm out) oscillators the sensitivity is not good enough. I read in an old article by Walls, Stein et al(Design considerations in state-of-the-art signal processing and phase noise measurement system) that one can use two diodes in series in the double balanced mixer to increase the sensitivity. I tried this with some standard 1n5711 Schottky and the sensitivity is now 1V/rad, but is there a easier way to do this? /Anders ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] C-MAC hookup
Joe do you have a model number I have a C-Mac data book for this company and they have a wide variety of packages Alan G3NYK - Original Message - From: Joseph Gray jg...@zianet.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, November 24, 2012 3:21 AM Subject: [time-nuts] C-MAC hookup A friend just got a C-MAC Sine 10MHz Double Oven Oscillator and asked me to see if anyone here knows how to hook it up and get it working. Joe Gray W5JG ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 12.8 MHz OCXO
Joe the reason why its not so uncommon may not be obvious in the US :-)) 12.8MHz is used as a reference for commercial and amateur PLLs in Europe where the common channel spacing is 12.5kHz (/1024) or 6.25kHz (/2048). This may mean that 12.8MHz oscillators may be more easily found in Europe ?? A TCXO should be capable of 0.1ppm. I have seem a lot in mobile/cellular product from a UK firm called Golledge but I dont know what the specs were. Alan G3NYK - Original Message - From: Joseph Gray jg...@zianet.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, November 24, 2012 3:59 PM Subject: Re: [time-nuts] 12.8 MHz OCXO David, Thanks for the links, but none of those meet my 0.25 ppm requirement. Joe Gray W5JG On Sat, Nov 24, 2012 at 1:55 AM, David C. Partridge david.partri...@perdrix.co.uk wrote: With only 0.25ppm needed would a TCXO do? Howsabout this: http://www.kuhne-electronic.de/en/products/special-offer/128-mhz-crystal-oscillator-tcxo.html or http://www1.futureelectronics.com/doc/IQD%20FREQUENCY%20PRODUCTS/E4191LF.pdf or even http://cgi.ebay.com/310376642284 Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Joseph Gray Sent: 24 November 2012 08:26 To: Discussion of precise time and frequency measurement Subject: [time-nuts] 12.8 MHz OCXO Can anyone recommend an inexpensive 12.8 MHz OCXO that outputs a sine wave? I've looked online, but the only ones I find costs hundreds of dollars. Anything 0.25 ppm or better is fine. A Vcc of 5-13.8 VDC preferred. Joe Gray W5JG ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Cinox source
Have you tried Princeton Applied Research who seem to own the EGG rights now?? Alan G3NYK - Original Message - From: johnk0...@juno.com To: time-nuts@febo.com Sent: Sunday, December 09, 2012 8:14 PM Subject: [time-nuts] Cinox source I realize this is pretty mundane for such an elite group, but would anyone have some information(specifically the pinout) for an EGG Cinox 10Mhz source. It has the following numbers printed on it: 10085-0611 and 20296-1891 and has three feedthrus labelled E1(orange wire), E2(black wire), and E3(yellow wire) and also a connector which is either an SMB or an MMCX(I can never remember which is which). Thanks for any and all help. John K0GCJ Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3131/50c4f158e437715802a6st02duc ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] noisy varactor diodes
The HP sceme in the patent refers to an array of series and parallel diodes to reduce noise. Just paralleling them does not reduce the noise! Might this not depend what the type of noise was ?? JRC use this technique in the RF stage of their receivers but I am wondering if this is only valid for Gaussian noise?? the faulty diode looked anything but Gaussian. Is there a situation here where we are not consider noise power which should add(??) but in the case of the JRC receiver S/S+N ..maybe C/C+N ( :-)) ) i.e it is the effect of the noise on the total capacitance in terms of the FM noise it produces?? The commonly called Zener diodes will work, all diffused diodes have an approximately square-law voltage capacitance relationship. Avalanche diodes (zeners above 6v Vbr :-)) ) are made with big junction areas so can give high capacitance. The lower the breadown voltage, the narrower the depletion layer so the bigger the static capacitance. However the surfaces might not be so well controlled as diodes intended for RF use. The noise demonstrated was probably a surface state effect rather than a bulk defect. Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 101, Issue 152
Volker.look at the subject line, the posting is in your hands, you dont need to just use the reply button, as somone did with a digest which forked the thread.. This means all the posing under Digest are hidden from view and searching. You can edit the subject line but this does not always return to the old thread if you use he reply button. I think it depends on the mail client. Alan G3NYK - Original Message - From: Volker Esper ail...@t-online.de To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, December 22, 2012 8:44 PM Subject: Re: [time-nuts] time-nuts Digest, Vol 101, Issue 152 Plot 1: MDEV of the time interval reported by GPSDO Yes, Said, that are important issues. By the way: I'm now writing in two threads, I don't know, why the original thread (Z3805A cooling requirements?) was splitted... Can we please move to the original thread? I am sure, that the noise of the GPSDO PPS-TI data is much to high to recognize the effects. I'm going to make a new setup, where I'll compare the GPSDO PPS with an external oscilator, e.g. an HP 10544 or the high stability reference within my SMX signal generator. Volker Am 22.12.2012 05:07, schrieb Said Jackson: Hi Volker, What is being plotted here? Efc? Time interval as reported by the GPSDO? External counter versus a stable reference? It looks like the resolution is approaching 10ns/s (1E-08 at 1s), and that the short term effects may be hidden in this noise? The effects are clearly visible in your first GPSCon plot, not sure if we can see the short term noise in these plots.. The 10811 I had tested went from ~3E-012 at 100s to ~2E-011 when the fan was on, I think both values are quite a bit below the noise floor of your plot so probably hard to measure. Bye, Said Sent from my iPad On Dec 21, 2012, at 6:47 PM, Volker Esperail...@t-online.de wrote: Said, Unfortunately I don't have the equipment to measure the phase noise of an HP 10811 (yet). But I did some work on evaluating the results of my fan experiment. Within this posting you'll find two diagrams. The first (named 1_DF9PL...) shows five MDEV curves (Modified Allan Deviation), each of them measured at different times. Total time span is 30.5 hours. At small tau values (up to 1000 s) only a slight increase of sigma over time can be noticed. However, at a tau of 5000 s or greater you can watch sigma making a big bump. Ok, that's what we expected before. In diagram no. 1 it's somewhat fussy to recognize the change of a particular sigma(tau). Now, that we've got curious, we want to see, how the sigma(tau) changes over time. So I've been providing a second diagram (2_...), where sigma(tau) is a function of the time. You can see, for example, the curve of tau=20480s developing a big hump, and falling back to a proper value after about 1800 minutes. All curves at a tau greater or equal 2560 do so. At smaller values the curves are esentially less affected, but - they are not back at their starting value after 1800 minutes (30 hours)! You could guess, that the hump moves up to longer times with increasing sigma - but it doesn't. There is something significantly different below tau=2560s. 1 hour ago, I switched off the fan and laid back the aluminium cover. We wait and see. And now, dear time nuts, it's time to go to bed. Volker Am 21.12.2012 18:53, schrieb Said Jackson: Mark, Your plot still shows excursions of +/-1E-010, about 100x higher base noise than the Z3801A/Z3805A are capable of achieving. Wonder where that noise is coming from? This noise is probably much higher than the thermal effects. The original post was the question does my Z380xA have reduced stability if I add a fan or similar, I think the answer is shown to be yes. Volker, I wonder if you also see fan-induced spurs in the phase noise from 1Hz to 100Hz. I would not be surprised if the fan vibration adds significant spurs to the 10811A crystal. Bye, Said Sent from my iPad On Dec 21, 2012, at 9:42 AM, Mark Spencermspencer12...@yahoo.ca wrote: This plot should show the frequency change more clearly. (Same data just presented differently.) It seems to me that the noise goes may be going down a bit for a minute or so just after the fan is turned on but I don't believe these plots provide conclusive evidence of this. Regards Mark Spencer Message: 7 Date: Fri, 21 Dec 2012 09:27:29 -0800 From: Said Jacksonsaidj...@aol.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Cc: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Z3805A cooling requirements? Message-ID:83ce0384-2996-4155-b51b-9d79910b2...@aol.com Content-Type: text/plain; charset=us-ascii Great plots guys! Looking at these results I think my original claim still holds: ADEV goes up when a fan is involved versus no fan, even on a double oven
Re: [time-nuts] Questions about TAC frontend, and some measurements
Hi Fabio taking BJTs deep into saturation stores a lot of charge in the collector base capacitance. this must br discharged before a state change can occur. LSTTL gets round this and gets the speed at lower currents by clamping the collector to only just in saturation with a schottky diode between base and collector. Higher speeds are obtained with a long-tail pair like configuration, which switches (diverts) the current flow between left and right transistors for the two logic states. The current and power dissipation is high but speeds 10 times saturated logic are obtainable. see ECL, MECL, or PECL logic family schematics. Alan G3NYK - Original Message - From: Fabio Eboli fabi...@quipo.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, December 22, 2012 11:00 PM Subject: Re: [time-nuts] Questions about TAC frontend, and some measurements Hello, Bruce Using saturated transistors as switches in the current source and elsewhere isn't conducive to fast switching. The traditional arrangement using current mode switches is much faster and more predictable. This is something I'd like to understand better. I'm referring to this schematic here: http://www.flickr.com/photos/14336723@N08/8293076065/ Q2 and Q5 are saturating toward the end of the ramp pulse, when the ramp capacitor C1 starts to go up. I was prepared to see the circuit I designed fail miserably on switch time, but it seem to be working, as far as I could see on the DSO. As far I can understand, the fact that Q2 and Q6 don't saturate, saves the circuit, since at the end of the ramp, when Q1 and Q5 are into saturation, Q6 is able to steer the current to ground, and reverse bias BE (and CB) of Q5. Is this correct, or I was only lucky with the specific parts I used? Buffering the ramp with an opamp requires that the opamp settling time be known so that the opamp has fully settled before a sample is taken. With a charge redistribution ADC that has a sampling switch connected to a capacitor array a buffer isnt usually necessary. Bruce I was planning to read the voltage with a microcontroller's ADC. I will set a fixed delay from the PPS rising edge and start sampling there. To do so I need that the voltage on integrating capacitor to stay reasonably stable during the delay. Fabio ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] YIG oscillators
Hi Daniel, I cant remember the reference the web site might help but there have been at least a couple of articles on YIG modules in VHF Comms magazine Alan G3NYK - Original Message - From: Daniel Mendes dmend...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, January 04, 2013 2:19 PM Subject: [time-nuts] YIG oscillators Hi, maybe this topic is a bit boundary for this list, but i´ll just ask for general directions I´ve discovered these wonderfull bits of hardware called YIG (Yttrium iron garnet) Oscillators (and filters!) in Ebay. If someone doesn´t know what i´m talking about, they are very broadband tunnable oscillators and filters. Now, the questions: 1) Does someone has some good references about them? 2) Can I get them new from somewere in decent prices or just collect the trash from ebay? (as most of our Rubudium, OCXOs, Thunderbolts, etc) Thank you for any help... Daniel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] eLoran for GPS backup
Hi Chuck, It never went off!! The French are spear-heading this. An experimental eLoran station was run from Rugby (GBR site) before it finally closed then the gear was relocated to be run by VT Communications, now Babcock I believe, based on Anthorn (south bank of the Solway Firth). This uses the gear that was originally destinded for Loop Head in Ireland (but cancelled due to local protest) as the 3rd slave on the Lessay chain. Anthorn is not ideal but it was already a Mil VLF (19.6kHz) site. The original experiment was mounted from Trinity House, the Lights an Nav authority for the UK, at their base in Harwich just across the river from me. The French have attempted to resurect the Mediteranean chain but have had no interest. Most of the financers of the Baltic Sylt chain do not seem enthusiastic but it remains on (I believe subsidised by the French) Alan G3NYK - Original Message - From: Chuck Forsberg WA7KGX N2469R c...@omen.com To: ExTek gatesja-l...@eskimo.com; time-nuts time-nuts@febo.com Sent: Wednesday, January 09, 2013 8:04 AM Subject: [time-nuts] eLoran for GPS backup The Brits are turning their Loran system back on to protect against GPS outages from jamming or space weather: http://www.gpsworld.com/uk-switches-on-eloran-for-backup-in-the-english-channel/ -- Chuck Forsberg WA7KGX c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT - USB to LPT Adapter - Does it exist?
I dont have the reference in front of me but it might just be worth checking the article archive for the Elektor magazine.I have a vague feeing I might have seen something there. Many of their past projects have used the LPT as a programmable port. There should be an article index on their web site I think. Alan G3NYK - Original Message - From: J. L. Trantham jlt...@att.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, January 11, 2013 1:09 PM Subject: [time-nuts] OT - USB to LPT Adapter - Does it exist? Not sure where to ask this question but thought I would start here. Is there a way to connect a parallel port to a computer via USB? Not a device that shows up as 'USB Print Support' but, instead, shows up in Device Manager as an LPT port? I have been able to do it via PCMCIA to Parallel Port adapters but I have never found a USB device that would do this. My goal is to connect a parallel port chip programmer via USB but the software only looks for LPT ports. It works with PCMCIA to parallel port adapters but I haven't solved the puzzle yet with a USB connected device. Thanks in advance. Joe ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PTS 3200 remote programming
Hi Iban do you have a manual? they are available. From memory because its a while since I worked on my Wavetek- Rockland unit I believe the remote programming is in parallel with the front panel switches. The reason for raising this is that there may be a problem on the back of the panel switches.mabe a wire off. Does the 800Mhz front panel switch setting work correctly ?? Alan G3NYK - Original Message - From: Iban Cardona icard...@gmail.com To: time-nuts@febo.com Sent: Friday, March 01, 2013 6:42 PM Subject: [time-nuts] PTS 3200 remote programming Hi, I'm traying to use to program the bcd interface of a PTS 3200. My truble us tha the 100Mhz decade 8 value bit is ignored by the PTS, then if I send 800Mhz to the PTS dont get output, and if send 900Mhz then I get 100Mhz. I checked the unit and the hardware looks OK. And my code is working well in another PTS units like the 620. The 3200 have some trick? Thanks for all 73! Iban eb3frn ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PTS 3200 remote programming
Hi Iban well my knowledge of the older generation is not much use to you :-)) still I always think any response will bring more comments out of the woodwork even if only to correct the false impressions. The suggestion of of a faulty chip on that remote digit sounds like a worthwhile way to go. Good Luck with it these are useful units if a bit big by modern standards. Best Wishes Alan G3NYK - Original Message - From: Iban Cardona icard...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 02, 2013 12:37 AM Subject: Re: [time-nuts] PTS 3200 remote programming Hi Alan, thanks for answer. Yes I have the manual, but the latches on my pts not are as are showed in the user manual. Maybe my unit it is a different version or release, or have some customozation from the pts guys. In myunit, I tested the SO-2005 module that is that generates the 100Mhz decade, and I tested manually the 4bit to generate the 800Mhz and works well. My unit dont have front panel, only can be controllated remotelly. The differences from the user manual, is that un the user manual the 1ghz and 100mhz decade shares latch, and in my unit the shares latch the 100mhz with the 10mhz. The 1ghz latch is shared by the 1hz decade. Best regards 73! Iban eb3frn On Fri, Mar 1, 2013 at 8:27 PM, Alan Melia alan.me...@btinternet.com wrote: Hi Iban do you have a manual? they are available. From memory because its a while since I worked on my Wavetek- Rockland unit I believe the remote programming is in parallel with the front panel switches. The reason for raising this is that there may be a problem on the back of the panel switches.mabe a wire off. Does the 800Mhz front panel switch setting work correctly ?? Alan G3NYK - Original Message - From: Iban Cardona icard...@gmail.com To: time-nuts@febo.com Sent: Friday, March 01, 2013 6:42 PM Subject: [time-nuts] PTS 3200 remote programming Hi, I'm traying to use to program the bcd interface of a PTS 3200. My truble us tha the 100Mhz decade 8 value bit is ignored by the PTS, then if I send 800Mhz to the PTS dont get output, and if send 900Mhz then I get 100Mhz. I checked the unit and the hardware looks OK. And my code is working well in another PTS units like the 620. The 3200 have some trick? Thanks for all 73! Iban eb3frn ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Don't use cheap cables -- a cautionary tale
Some of the older synchronised signal generators (2-box systems) e.g Marconi, used TNC connectors with solid coax where signal leakage was likely to be a problem. Alan G3NYK - Original Message - From: Volker Esper ail...@t-online.de To: time-nuts@febo.com Sent: Sunday, March 03, 2013 6:49 PM Subject: Re: [time-nuts] Don't use cheap cables -- a cautionary tale Yes, we all have to learn that lesson... At the time I use bedea RG-223 and Belden H155 with soldered and crimped Telegaertner BNC connectors as general purpose cable (up to 2 GHz). Above that frequency I wouldn't use BNC. If you simply connect your tracking generator with the spectrum analyzer by using such a BNC cable there's not one that is absolutely stable when stressing the connector. I tried several manufacturers, HP, Suhner, Radiall, Rosenberger, it's always the same. To make precise measurements I prefer screwed connectors like N or SMA. Volker ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Releasing sources (was Re: Brooks Shera)
Hi John Please dont take it down! remember there are more of us who quietly appreciate sites like yours. I once suggested to a query the answer was in the help file and background by googling or using wikipedia, and was told it was a lot easier and quicker to play dumb and ask.!! I also suggest you do as some do and say This is not a beginners project. If you do not understand the requirements or have the construction skills, please dont expect support for a freebie It prob wont stop it but it will give your a clearer conscience when you decline to reply :-)) Alan G3NYK - Original Message - From: NeonJohn j...@neon-john.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, March 28, 2013 6:16 PM Subject: [time-nuts] Releasing sources (was Re: Brooks Shera) On 03/25/2013 09:36 AM, Jim Lux wrote: One reason is that if one DOES release source, one will wind up supporting it, because generally, we all nice people and helpful, and it's hard to tell someone no when they send an email asking how to get it to compile on Version N+3 when you used version N, etc. This can be a real distraction from whatever else you are doing. Boy, you can say that again. And open source hardware is even worse. A couple of years ago I put up an open source induction heater on my site. Everything included - schematics, board layouts, CAD files, theory of operation, how to wind the transformer - in short, everything I could think of. There's even a kit available from Fluxeon.com. Yet I probably spend an hour a day responding to emails about that project. Approximately 100% of the questions are either answered on my site or by a little googling. It's getting to be enough of a burden that I'm considering taking the page down. I'm a dedicated supporter of Open Source but this experience has tempered my enthusiasm a bit. And then there's the folks who argue with you about your implementation or coding style. Or electrical design style. I think that the people who want to argue design, especially what if I did this? type arguments are more tiresome than the software know-it-alls. People need to really think and do their Google homework before hitting the email button on a project site. John -- John DeArmond Tellico Plains, Occupied TN http://www.fluxeon.com -- THE source for induction heaters http://www.neon-john.com-- email from here http://www.johndearmond.com -- Best damned Blog on the net PGP key: wwwkeys.pgp.net: BCB68D77 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GPS antenna??
Hi all an interesting problem you may have encountered, I want to use a GPS frequency standard inside a building with no opening windows (opening windows are known as air conditioning in the UK :-)) ) This is part of a two day amateur microwave conference so we should have the expertise. I intend to try and pass the signal through a a double glazed glass window unit (hopefully not metalised) using a couple of patch antennas. The outer GPS antenna is active so will need a 5v supply via an inserter. Inner patch active, outer patch passive to avoid problems of feedback. Main antenna can be shielded from the coupling either physically or with a slab of absorber. Has anyone tried this? does it work?.any gotchas? Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS antenna??
Hi Bob yes it is South facing.I may have todo that anyway because the window may be too far above ground level (the land slopes away from the ground entrance.. pity I had totally forgotten that. Thanks Alan G3NYK - Original Message - From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Monday, April 08, 2013 8:28 PM Subject: Re: [time-nuts] GPS antenna?? Hi Is the proposed window south facing? If not, you will need enough cable outdoors to get your second antenna to a south facing location. Assuming it's south facing and reasonable sky view, have you tried a patch antenna on / at the window? That should at least give you some idea of how likely the signal is to get through it. It's not uncommon to run GPSDO's with window mounted antennas. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Alan Melia Sent: Monday, April 08, 2013 1:00 PM To: time-nuts measurement Subject: [time-nuts] GPS antenna?? Hi all an interesting problem you may have encountered, I want to use a GPS frequency standard inside a building with no opening windows (opening windows are known as air conditioning in the UK :-)) ) This is part of a two day amateur microwave conference so we should have the expertise. I intend to try and pass the signal through a a double glazed glass window unit (hopefully not metalised) using a couple of patch antennas. The outer GPS antenna is active so will need a 5v supply via an inserter. Inner patch active, outer patch passive to avoid problems of feedback. Main antenna can be shielded from the coupling either physically or with a slab of absorber. Has anyone tried this? does it work?.any gotchas? Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS antenna??
Hi Tom yes I have produced some similar plots I think they get cold feet about 70deg N. I'm not sure of the actual value it is a long time since I played with that last. Alan - Original Message - From: Tom Van Baak t...@leapsecond.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, April 08, 2013 9:19 PM Subject: Re: [time-nuts] GPS antenna?? Aren't GPS birds all over the sky. South facing is for the Clarke belt. Well, mostly all over, but with higher probability facing up, east, west, and towards the equator compared to significant black hole towards the pole. For example, see the GPS reception sky map of John's TBolt: http://ke5fx.com/heather/readme.htm For those of you down under, the hole is south rather than north, of course. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS antenna??
Hi David yes its ferro-concrete which makes quite a good screen (a lot worse than domestic brick) but the windows are not coated I think. (BT Labs at Martlesham) Thanks all for some thought stimulating ideas .GPSDO outside might not be too easy1U rack case mains poweredno power available outside but 10MHz (or 5MHz in this case) coupling through wall or window is a lot easier if I had a battery powered unit.I have a feeling there may be battery back-up terminals on it must get the book out. The windows are SW I think but give a good view of a quadrant of the sky. It will be interesting to see how long it takes to lock up compared with an outside antenna. Thanks and Best Wishes Alan G3NYK - Original Message - From: David J Taylor david-tay...@blueyonder.co.uk To: time-nuts measurement time-nuts@febo.com Sent: Monday, April 08, 2013 7:46 PM Subject: Re: [time-nuts] GPS antenna?? Hi all an interesting problem you may have encountered, I want to use a GPS frequency standard inside a building with no opening windows (opening windows are known as air conditioning in the UK :-)) ) This is part of a two day amateur microwave conference so we should have the expertise. I intend to try and pass the signal through a a double glazed glass window unit (hopefully not metalised) using a couple of patch antennas. The outer GPS antenna is active so will need a 5v supply via an inserter. Inner patch active, outer patch passive to avoid problems of feedback. Main antenna can be shielded from the coupling either physically or with a slab of absorber. Has anyone tried this? does it work?.any gotchas? Thanks Alan G3NYK === Alan, Here I am on the top floor of a standard house, and get an adequate signal for today's GPS receivers with simple patch antennas. One GPS I have is in a walk-in cupboard adjacent to a north-facing outside wall. Obviously, there are no guarantees, but you may get away with just being adjacent to an outside wall, or getting the puck near the non-opening window (but that may be worse than the wall). If it /must/ be a GPS relay like you are suggesting, perhaps for multiple receivers inside a room, I can't help. Be sure to place the puck on an appropriate ground plane - I find a clean, unused baking tray to be perfect! 73, David GM8ARV -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS antenna??
Hi Tom Ah I didnt realise there were such beastsI probably have not the time left now but it is one to consider. Yes I might have to watch the patch polarisation. I did consider two L-band waveguide transitions at one stage but thought that might be going too far :-)) I thought of the on-glass antenna used in the days of The Brick on mobile cellular, or amateur and commercial 2-way radios. Thanks again for the ideas. Alan G3NYK - Original Message - From: Tom Van Baak t...@leapsecond.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, April 08, 2013 10:12 PM Subject: Re: [time-nuts] GPS antenna?? Alan, Google for words like GPS re-radiator or GPS repeater. There are also units on eBay. If not to buy, at least to study examples. The one I have is made by www.gpssource.com but it seems you could build one yourself. It's easy to test by looking at your indoor SV count and reception levels. With patch antennae you don't have to worry about RHCP issues, right? /tvb - Original Message - From: Alan Melia alan.me...@btinternet.com To: time-nuts measurement time-nuts@febo.com Sent: Monday, April 08, 2013 9:59 AM Subject: [time-nuts] GPS antenna?? Hi all an interesting problem you may have encountered, I want to use a GPS frequency standard inside a building with no opening windows (opening windows are known as air conditioning in the UK :-)) ) This is part of a two day amateur microwave conference so we should have the expertise. I intend to try and pass the signal through a a double glazed glass window unit (hopefully not metalised) using a couple of patch antennas. The outer GPS antenna is active so will need a 5v supply via an inserter. Inner patch active, outer patch passive to avoid problems of feedback. Main antenna can be shielded from the coupling either physically or with a slab of absorber. Has anyone tried this? does it work?.any gotchas? Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Low-pass Filter for 5 and 10 MHz
Maybe a silly question but isnt the phase response of the filter important in this application ?? notches have fairly vicious phase shifts. Alan G3NYK - Original Message - From: Luciano Paramithiotti timeok...@gmail.com To: time-nuts@febo.com Sent: Thursday, April 11, 2013 5:42 PM Subject: [time-nuts] Low-pass Filter for 5 and 10 MHz A simple low pass filter to cut second and third harmonics from a 5 or 10 MHZ signal. See the paper: http://www.timeok.it/files/5_and_10mhz_low_pass_notch_filter.pdf Luciano Timeok ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Brooks Shera ASM release
Bert is there any way we can add our names to some expression of thanks to his widow Karen and her helpers for their work and maybe leave a remembrance of his worldwide friends for his family? Thanks for your efforts Best wishes Alan Melia (G3NYK) UK - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Friday, April 12, 2013 8:52 PM Subject: [time-nuts] Brooks Shera ASM release The time-nuts server takes out all spaces so allow me to resend the acknowledgementsBert Kehren At this time I like to thank Brooks for all the work he did, his wife Karen Stoll for deciding to release HEX and ASM and Bob Leichner who implemented the software commands. Brooks did not have the chance to put final touches in and complete his work, so Richard McCorkle stepped in and made the final changes. For almost a decade Brooks and Richard collaborated on the GPSDO, which benefits all of us. Also major recognition has to go to Juerg Koegel an other time nut that put our other projects on hold to check every iteration. Attached is part of a test that clearly shows the performance of the Alpha filter. Limited by attachment size contact me off list for more data. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Brooks Shera ASM release
Ok Bert I will stick my head above the parapet and repeat that query.Sometimes it is frustarting the get no response, but later get personal appreciation as you meet individuals. I didn't know the guy. I was trying with a friend to contact him long after the original article. We were disapointed but not unhappy. I certainly appreciate the help and expertise the Group provides..and it is nice to be able to say so, and salute the work Brooks did. Thanks and Best Wishes Alan Melia (G3NYK) - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Monday, April 15, 2013 8:17 PM Subject: Re: [time-nuts] Brooks Shera ASM release Alan You may suggest something to time nuts, looking at the response I doubt it and ask my self why did three of us spend three weeks to fully check it out and fix some of the code. Will reflect future projects. Bert Kehren In a message dated 4/12/2013 8:39:40 P.M. Eastern Daylight Time, alan.me...@btinternet.com writes: Bert is there any way we can add our names to some expression of thanks to his widow Karen and her helpers for their work and maybe leave a remembrance of his worldwide friends for his family? Thanks for your efforts Best wishes Alan Melia (G3NYK) UK - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Friday, April 12, 2013 8:52 PM Subject: [time-nuts] Brooks Shera ASM release The time-nuts server takes out all spaces so allow me to resend the acknowledgementsBert Kehren At this time I like to thank Brooks for all the work he did, his wife Karen Stoll for deciding to release HEX and ASM and Bob Leichner who implemented the software commands. Brooks did not have the chance to put final touches in and complete his work, so Richard McCorkle stepped in and made the final changes. For almost a decade Brooks and Richard collaborated on the GPSDO, which benefits all of us. Also major recognition has to go to Juerg Koegel an other time nut that put our other projects on hold to check every iteration. Attached is part of a test that clearly shows the performance of the Alpha filter. Limited by attachment size contact me off list for more data. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Brooks Shera ASM release
Bert I am grateful for the work you and friends have done. Is there any way we can add our names to some expression of thanks from members of the Group to his widow Karen and her helpers for their work in making the checked source code for the GPSDO available to us and maybe leave a token of remembrance of his worldwide friends, for his family? Even if it is just a me too replying to this message. Alan Melia (G3NYK) Ipswich, UK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Italian Time Station on 10 MHz ?
Hi Marco maybe you should run a web site with daily measurements and shame them into doing it properly ( your traceable to NIST should raise some hackles !!) I took me four months to get a short term wander on 198kHz looked at a few years ago. I was cured when the synth finally failed completely ! The private contractor did not have at the time any way of measuring it off-air, despite taking the NPL money for running it. :-)) Alan G3NYK - Original Message - From: Marco IK1ODO -2 ik1...@spin-it.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, April 28, 2013 9:25 PM Subject: Re: [time-nuts] Italian Time Station on 10 MHz ? For what I know they have an experimental license by the Telecom authority, and operate from Tuscany near Viareggio since two or three years. The license has been given on the basis that there are no more HF time and frequency signals operating in Europe. When I knew about it I offered to donate a rubidium standard, to have it at least on the right frequency. I had no answers... they continue to radiate a worthless off-frequency signal (IMHO). May be it is a case of beaconitis :-) (a disease that mandates to activate beacons). On a similar base, I know of an attempt to restore and put in operation the old transmitter of IBF (5 MHz, Istituto Nazionale di Elettrotecnica, now INRIM, the national standard keepers). That was a custom built 5 kW (carrier) Continental broadcasting TX. It has been found in the underground storage of INRIM, stripped of power and modulation transformers, and should be rebuilt to operate at only 1 kW carrier on the original 5 MHz frequency (Rb or GPS controlled!). The plans are to operate it from the original place on the hills near Torino, by remote control, as a museum and educative item. I offered my workshop to work on it, I hope that the project may go on to again hear IBF, IBF, IBF, standard time and frequency signals from the National Electrotechnical Institute, Turin, Italy from minutes 45 to 60 on 5 MHz ;-) Marco IK1ODO / AI4YF ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OCXO Adjustment Question
I use this method too, but I also find it little use trying to get the internal reference down to the last squeak in 10^11 on this kind of kit. It will not hold the setting for vey long and it takes ages to get the adjustment spot on. I get as close as I can easily.then allow the unknown to stabilise and do an estimate of the error and stick a label with thay value on the front until the next check is required eg 2 in 10^9 high 6thApr13 ..would not suit an avid time-nut but then the equipment is often barely time-nut quality :-)) Alan G3NYK . - Original Message - From: Bill Riches bill.ric...@verizon.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Wednesday, May 08, 2013 11:52 AM Subject: Re: [time-nuts] OCXO Adjustment Question This is the method I use for my 5110. There are two 10 mhz outputs on the osc - you can unplug one of the plugs and use a 10x probe there. My unit will hold a couple of parts in 10-8 for months. 73, Bill, WA2DVU Cape May, NJ -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Tuesday, May 07, 2013 11:52 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] OCXO Adjustment Question Fred, What I do is to apply the GPSDO to the trigger input of a scope and the output of the OCXO to be adjusted to the vertical input of the scope. Set the time base to something line 100 nSec or faster and watch the output of the OCXO after it has warmed up for 30 minutes or so. This is an option only if you have an output from the OCXO you can watch. If no output, try a x10 probe attached to a 10 MHz connection from the OCXO inside the monitor. However, be careful that the probe does not 'load' the OCXO and shift the frequency. Adjust the OCXO for a stable display, not drifting left or right. If the sine wave (or square wave) is moving to the left, the OCXO is high in frequency. If it is moving to the right, the OCXO is low in frequency. If stable, it is matched to the GPSDO. This is useful as long as the OCXO and GPSDO are within a few Hz of each other. The amount of time it takes for the display to shift 1 cycle tells you how close the OCXO is to the GPSDO. For instance, if it takes 10 seconds for the display to shift one cycle, 100,000,000 +/- 1 cycles went by in that 10 seconds or 1 part in 10E9 if I have my math correct. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Frederick Bray Sent: Tuesday, May 07, 2013 9:25 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] OCXO Adjustment Question This might be slightly off-topic, but probably there is a time-nut who knows the answer. I am trying to adjust the 10 MHz OCXO in a Cushman 5110 service monitor. I am using a frequency counter driven by a GPSDO. Perhaps someone can educate me about a couple problems I am encountering. I tried making small incremental adjustments but after I am done, the frequency drifts several Hz and then re-stabilizes at a new value. When I make further adjustments, I notice strange behavior. For example, if I initially turned the adjustment clockwise to increase the frequency, it will now decrease if I turn it clockwise and increase if I turn it counter-clockwise. On the next adjustment, it will reverse again. Is there some correct procedure to adjust an OCXO? Many thanks for any suggestions. Fred Bray ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Ground loops in measurements?
Hi Bob whats the problem at low freqs ?? I thought leakage was a function of the size of the holesv the wavelengthor are we into braid skin effect below 100kHz?? so as not to drag this OT a reference will suffice in answer. Best Wishes Alan G3NYK - Original Message - From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Monday, May 20, 2013 6:00 PM Subject: Re: [time-nuts] Ground loops in measurements? Hi Coax is interesting stuff. The shielding is only good down to some lower frequency limit. For anything practical that's going to be 100 KHz. At the frequencies you *should* use coax at, transformer coupling is the easy way to break the ground loop. In this era of cell phones all over the place, a transformer plus some sort of common mode choke is the standard approach. For things like 1 pps, you should be using some sort of balanced transmission. Twisted pair, or better, shielded twisted pair. You can either run into a balanced receiver IC and dc couple or into a transformer and do something a bit fancier. With the IC you have a maximum voltage offset that can be tolerated. With the transformer you have the cost / delay / possible error in picking up the edges. If your environment is noisy enough, you may have to transport your pps on some sort of carrier. RF and optical both have their fans. None of that is going to be easy. The alternative is to do what you would do in a screen room. Single point ground, everything tied tightly together. Put reasonable filtering on everything in and out. Tie the filters to the common ground point. This also is not easy, but possibly not as hard as redesigning the ins and outs of every box in sight. I have seen this approach used on some *very* large systems. A some what extreme approach (that I have seen used). Forget about all the shielding and stuff. Buy a farm, put up a small metal shack in the middle of a large field. Bring a hand cart with batteries. Run everything on a big copper covered table. Lots of ways to go. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila Kinali Sent: Monday, May 20, 2013 8:08 AM To: time-nuts@febo.com Subject: [time-nuts] Ground loops in measurements? Moin, A couple of weeks ago, there was a short discussion on bad connectors and cables and the coupled in noise of those. Summarized it said that measurements in the time-nuts scale are very sensitive to even the lowest noise levels and coupled in signals. But, all the measurements we do are done using some sort of coax which have their shield connected to the case of the devices. As the invovled devices in a measurement are also grounded over their power supply this will lead to ground loops and thus a 50/60Hz noise. Also, because loops are good magnetic antennas, a lot of other noise floating around in the ether is coupled in (eg a nearby radio station). How do you handle this kind of problems? Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] synchronizing a large number of weakly coupled oscillators
Well I guess no because accuracy is the deviation from a known standard (I think) Stability repeatability might be better but you need to consider what the variables might be. Variations in thickness (basically frequency), cut angle (temp coeficient and maybe others), crystal purity (aging, ESR ?). If you average many randomly selected samples you might reduce the level of variablilty of these aspects but would that make them more accurate? I doubt that maybe more capable of staying within a given accuracy once adjusted. I still think the cost effective way is get one good one, the best you can afford, characterise it and the make adjustments either calculated or by disciplining. Even an ordinary crystal can be made to perform quite well by adjusting it to track it to something better. Many LF BC stations in Europe are much better than a cheapy (computer grade) crystal and Droitwich and Allouis are locked to a Rb standard and regularly measure against the national standards. A few part in 10^11 costs a couple of hundred dollars.This is 5 orders better than a cheapy crystal. My back of envelope calculation suggest you might need about 100,000 oscillators to achieve this level (ok tell me I'm wrong with the calculation and, as the exam script says, show you working .the red wine was very nice I can take it !! :-)) ) Alan G3NYK - Original Message - From: Hal Murray hmur...@megapathdsl.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, May 12, 2010 11:31 PM Subject: Re: [time-nuts] synchronizing a large number of weakly coupled oscillators Presumably, a large population of cheap coupled oscillators could be rather accurate collectively. Why? There are 2 main sources of error in inexpensive crystal oscillators. The first is the initial manufacturing error. I'd expect crystals made from the same batch to have similar errors. If you want a large population, you are going to get most/many of them from similar batches. The other is temperature. I'd expect that oscillators of a specific design to have similar temperature dependencies. Some vendors even include a graph in their app-notes. It might be interesting to collect oscillators from different vendors and batches and see what sort of spread you end up with. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 70, Issue 31
Is it possible that mechanical (pendulum) clocks could couple not due to energy transfer between the clocks but external mechanical events such as seismic events of a very low level ?? or even gravitational or lunar gravitational effects.?? Maybe the same for water clocks ?? Alan G3NYK - Original Message - From: Christopher Hoover c...@murgatroid.com To: time-nuts@febo.com Sent: Thursday, May 13, 2010 1:00 AM Subject: Re: [time-nuts] time-nuts Digest, Vol 70, Issue 31 On 5/12/2010 10:41 AM, Jim Lux wrote: It never occurred to me that they might couple, although almost every other mechanical clock does. What would the mechanism be? Perhaps if all of them run off the same reservoir ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 70, Issue 31
Nice reference thanks for those Stanley...interesting, thought provoking reading! Moving apart and possibly changining the relative positions of the plane of the swing too to test the coupling. There are ways of measuring this if you have the time :-)) My thought was that even an uncoupled set might move closer together if all subject to the same external impulse? Alan - Original Message - From: Stanley Reynolds stanley_reyno...@yahoo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, May 13, 2010 2:19 AM Subject: Re: [time-nuts] time-nuts Digest, Vol 70, Issue 31 That would not explain the lessing of the effect as the clocks are moved father from each other or arranged as sides of a triangle. Maybe gravity between the pendulums or more likely vibrations. http://www.scholarpedia.org/article/Synchronization http://www.siam.org/pdf/news/481.pdf http://www.bhi.co.uk/hj/Coupled%20Pendulums%20Quadrature%20and%20Clocks%20by%20John%20Haine.pdf http://www.ralph-abraham.org/articles/MS%2344.Resonance/ms44.pdf Stanley - Original Message From: Alan Melia alan.me...@btinternet.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wed, May 12, 2010 7:12:55 PM Subject: Re: [time-nuts] time-nuts Digest, Vol 70, Issue 31 Is it possible that mechanical (pendulum) clocks could couple not due to energy transfer between the clocks but external mechanical events such as seismic events of a very low level ?? or even gravitational or lunar gravitational effects.?? Maybe the same for water clocks ?? Alan G3NYK - Original Message - From: Christopher Hoover c...@murgatroid.com To: time-nuts@febo.com Sent: Thursday, May 13, 2010 1:00 AM Subject: Re: [time-nuts] time-nuts Digest, Vol 70, Issue 31 On 5/12/2010 10:41 AM, Jim Lux wrote: It never occurred to me that they might couple, although almost every other mechanical clock does. What would the mechanism be? Perhaps if all of them run off the same reservoir ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lucked out
The ones they cant get to work are the most fun...:-)) Alan G3NYK - Original Message - From: Bruce Lane kyr...@bluefeathertech.com To: time-nuts@febo.com Sent: Friday, May 21, 2010 11:31 PM Subject: [time-nuts] Lucked out Fellow time-tickers, I lucked out on that NTS100i. No, it didn't have GPS (it was the IRIG version), but the fix was very simple. To recap: The Ebay seller had said he was unable to get it to synchronize to an IRIG input no matter how hard he tried. The solution: Turns out the IRIG version of the 100i (sub-model NIC-215) has a hardware jumper setting for different IRIG code formats. I discovered this when, on a whim, I fed the thing an IRIG-E stream -- and it locked! Some further experimentation located the jumper. I fed the thing a standard IRIG-B signal, then moved the jumper to different positions until I got a lock. One quick set of modified rack brackets later, the thing is doing its duty as a slave clock and NTP server, drawing its reference from my Odetics 425. I would call this $47 well-spent. ;-) Bruce Lane, Owner Head Hardware Heavy, Blue Feather Technologies (http://www.bluefeathertech.com) Assoc. member, AZA AAZK for many moons. Salvadore Dali's computer has surreal ports... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Apelco ...was Loran-C POSAID2 Software
Hi John I have a manual dated 1989 for a later version Apelco ( DXL 6300) The manual covers operation nicely, but the data for the Lessay chain is incorrect. I can enter the GRI manually and the receiver locks nicely. I have disassembled the eprom but cannot recognise the data areas to patch the right rates in, and associate them with the lat and long of the statons. I have tried the obvious paths but had no help the UK dealer ceased trading and filed earlier in the year. Their engineer did try to help but could not find information. Are you aware of any source of information on their products and updates?? I am in the process of turning this into a 10MHz locked source, (a couple of internal links) as it is not really too useful for Nav but it would be nice to get it working properly. Particularly as we look like having one of the last operational chains in Western Europe. Alan G3NYK - Original Message - From: J. Forster j...@quik.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, July 09, 2010 11:14 PM Subject: Re: [time-nuts] Loran-C POSAID2 Software A definite maybe. In the late 1970s, Raytheon farmed out their small boat LORAN receivers to a New Hampshire company, Appelco. They made 8085 based LORAN receivers w/ LED readout of time differences. Later, Appelco produced an upgraded version with a daughter board, also with an 8085, that took the data from the mother board and converted it to Lat/Long readout. Obviously, that daughter board had the needed SW in its ROM. Mine certainly worked on the bench and gave consistent positions to within about 100 feet. The model number was LC? I'm not certain there were many produced, but it might be worth a look. BTW, Raytheon places a muli-million dollar order w/ Appelco, then pulled the plug on a technicality. Appelco went bust. I got the stuff at their bankrupcy auction. The down side is I cannot put my hands on it any time soon. FWIW, -John The Coast Guard Research and Development Center has developed Coast Guard POSAID2 ver 2.1a, a DOS-based program for converting LORAN-C time differences (TDs) to latitude and longitude. As the old link at the USCG site is apparently broken, I wonder if someone in this novel group still has such an interesting program. Thanks in advance, Antonio CT1TE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Remove Pictic boards from envelopes
I have not been involved in this project but have had pcbs from eastern sources supplied to RoHS. Some have come in with bare copper pads. I wonder if the reason for this may be that their standard process was not tinning, but it was a a solder-flow stage, and they still have lead-tin solder baths. So they avoid the one proces involving lead to produce an RoHS produce. Other manufactures happily produce compliant tinned pcbs. I found the use of a flux pen was adequate to ensure even lead-free manual soldering even after the board had been in store for several months. Could there maybe be a thin flux coating over the pads which is cause the disquiet? Alan G3NYK - Original Message - From: Leigh L. Klotz, Jr WA5ZNU le...@wa5znu.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, August 10, 2010 6:38 AM Subject: Re: [time-nuts] Remove Pictic boards from envelopes I tried water, then isopropyl, but what worked was a quick cleaning with a white eraser. Leigh/WA5ZNU On 08/06/2010 08:15 AM, Ed Palmer wrote: You mean they are tinned? I received my two boards a couple of days ago. I thought that they missed the tinning solution. There's just an occasional splash of bright tin here and there, particularly on the back. The rest looks like oxidized copper. I haven't tried to solder them yet. Hope the rosin cuts through it. Ed Stanley Reynolds wrote: Please remove Pictic boards from envelopes when you receive them. Received a report that the tinning on the bottom of the board was discolored perhaps due to some contamination in the envelope. Will wrap boards in plastic wrap in the future. Stanley ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Remove Pictic boards from envelopes
Hi Jim ...being ironic...see the smiley Alan - Original Message - From: jimlux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, August 10, 2010 11:55 PM Subject: Re: [time-nuts] Remove Pictic boards from envelopes Alan Melia wrote: Pencil?? only us oldies know what that is... it is surprising the lead pencil hasn't been banned under RoHS :-)) Alan G3NYK I don't know that lead (as in the element) has ever been used in pencils.. I read a fascinating book on the history of the pencil a few years back.. it described how graphite (the mines of Cumberland were famous for graphite with good writing/drawing properties) was called plumbago (lead ore) because chemical analysis didn't really exist and the dense black substance seemed to resemble lead. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulation
Surely all this is a case of an engineer being able to read..specifications :-)) Manufactures specify to sell parts, most of the important parameter are minimum values, and the range is as wide as it can be. If you want a parameter bracketed then you must specify that when buying and pay the premium or take the expense of testing incomming batches for sensitive parameters. I used to give lectures to new engineers on reading specifications .and what Absolute maximum actually means. Clever engineers also love using operations that rely on unspecified parameters. For example using a stock switching diode as a spike quencher in a relay driver. The usually work (but not always!) but are generally not specified for that service. Spice parameters are probably a few typical samples of even the one I happened to choose to measure!! I had a case of some +/-12v transistor logic which made it was into a big telecoms project. the prototypes worked fine. By the time of bulk manufacture the supplier of the the main transistor had had several cost improvement stages. The result was the kit was unreliable. The problem was that first the base junction were swung to -12v by the 0 logic state and second from a transistor with a fairly simple round dot geometry emitter, the device had been replaced by an interdigital high ft chip (it still met the basic greater than specs.) The interdigital device suffered severe loss of gain after a period of avalanching at several millamps (I think it also suffered electromigration) much more than the circular geometry transistors. I think this was due to the increased emitter periphery length. It was solved by placing a simple diode in the emitter leg, or a clamp on the base. The engineer had not read, or not understood the meaning of the Vebmax = 5v parameter, and his prototype had worked. The production side were not very happy but eventually were forced to junk thousands of 8inch square pcbs and do a re-layout. This was in the days before computer simulation !! It might have helped! Alan G3NYK - Original Message - From: jimlux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, August 14, 2010 10:42 PM Subject: Re: [time-nuts] Simulation Hal Murray wrote: Line got moved to other side of big ocean. Process got tweaked beta is now 4x what it was. I'm pretty sure that military grade parts have paperwork and processes to cover that case. I expect it costs a lot. I think the same sort of service is available to high volume customers at a less than military price. just so.. In the space business, we call it traceability to sand... you haven't lived til someone has a failed 2n, somwhere on some piece of critical hardware, and they issue a GIDEP alert, and then the mission assurance folks call you up and ask, you don't by any chance have 2N's in your flight hardware do you?.. then there's the whole manufacturer and date code hunt.. Looking through the build documentation to find out. (or worse yet, if you had decided for some reason to use the prototype, which you didn't keep such good records on, but which you have photos of, and trying to read the date codes off the assembled item with a magnifying glass) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulation
Hi Bob yes that was a point raised by Prof Nat Sokal after I published some data, or rather he pointed out it happened in RF amps. I guess if you take an used PA transistor out of service and measure it you might find the base emitter junction very leaky, but does few mA of leakage matter so much in a low impedance high drive power circuit. Reliability asks does it do the job it was designed for not is it as good as new now Alan G3NYK - Original Message - From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, August 15, 2010 1:33 AM Subject: Re: [time-nuts] Simulation Hi Simulation might or might not have helped. 1) Was Vbe breakdown even included in the Spice model 2) If so did it ring bells (rare) or did it just clip without error ( common ) 3) Would the same designer who didn't understand it in the first place have seen it clipping at -5 and concluded looks to be in spec at -5 4) Would any of it be reviewed in light of the new transistor or was the guy on another project by then My favorite in the absolute max Vbe category is the typical class C RF amp. Look at the spec, check a few thousand working boards. Scratch head and move on. Lots of reverse bias on the base and they run forever. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GPS pcb IDs??
Hi I have just acquired a couple of GPS receiver pcbs, ex Telcoms equipment. I know a lot of htese poards were discussed so time ago on the group. Does anyone recognise what they are and could point me at some intrormations please. I am afraid the flash has washed the the pics out a bit but hopefully there is enough detail to be recognised http://www.alan.melia.btinternet.co.uk/GPS/Trimble_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Trimble_lower.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_lower.JPG The Trimble pcb is 2.6 by 1.25in., and the Synergy is 3.15 by 1.6 in. Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS pcb IDs??
Thanks Didier I will certainly let you know the results Alan - Original Message - From: Didier Juges did...@cox.net To: Time-Nuts time-nuts@febo.com Sent: Thursday, August 19, 2010 12:43 AM Subject: Re: [time-nuts] GPS pcb IDs?? Alan, You may want to compare to those: http://www.ko4bb.com/Timing/GPS_Pics/ If they do not match and you eventually find out what they are, please let me know and I will add them to my collection. That goes for anybody who has identified, clear pictures of GPS receiver boards, both sides preferably. Thanks in advance, Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Alan Melia alan.me...@btinternet.com Sender: time-nuts-boun...@febo.com Date: Thu, 19 Aug 2010 00:07:20 To: Time-Nuts measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] GPS pcb IDs?? Hi I have just acquired a couple of GPS receiver pcbs, ex Telcoms equipment. I know a lot of htese poards were discussed so time ago on the group. Does anyone recognise what they are and could point me at some intrormations please. I am afraid the flash has washed the the pics out a bit but hopefully there is enough detail to be recognised http://www.alan.melia.btinternet.co.uk/GPS/Trimble_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Trimble_lower.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_lower.JPG The Trimble pcb is 2.6 by 1.25in., and the Synergy is 3.15 by 1.6 in. Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS pcb IDs??
Stanley, Thank you very much for the rapid response I will browse those URLs and see if I can id the pcbs. Didier has advised he has a gallery so we should make good progress. Thanks Alan G3NYK - Original Message - From: Stanley Reynolds stanley_reyno...@yahoo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, August 19, 2010 12:38 AM Subject: Re: [time-nuts] GPS pcb IDs?? Synergy Motorola info here : http://www.wa5rrn.com/GPS%20Other/Motorola%20M12/5vltb.pdf UT+ Oncore R5xxxU Customer Specials trimble resolution t http://trl.trimble.com/docushare/dsweb/Get/Document-183796/13441+Resolution+FA2.pdf http://www.dpie.com/manuals/gps/trimble/ResolutionT_072408.pdf Stanley From: Alan Melia alan.me...@btinternet.com To: Time-Nuts measurement time-nuts@febo.com Sent: Wed, August 18, 2010 6:07:20 PM Subject: [time-nuts] GPS pcb IDs?? Hi I have just acquired a couple of GPS receiver pcbs, ex Telcoms equipment. I know a lot of htese poards were discussed so time ago on the group. Does anyone recognise what they are and could point me at some intrormations please. I am afraid the flash has washed the the pics out a bit but hopefully there is enough detail to be recognised http://www.alan.melia.btinternet.co.uk/GPS/Trimble_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Trimble_lower.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_lower.JPG The Trimble pcb is 2.6 by 1.25in., and the Synergy is 3.15 by 1.6 in. Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS pcb IDs??
Hi Didier, the Trimble is a Resolution T (3.3v)user manual at the URL quoted by Stanley (Thanks again Stanley) The Synergy is Motorola UT+ Oncore (5v) and I am sure the manual for those is around somewhere but not had time to chase that yet. Please feel free to add these to your gallery...I may have some more when I get round to taking some photos Thanks and Best Wishes Alan G3NYK - Original Message - From: Didier Juges did...@cox.net To: Time-Nuts time-nuts@febo.com Sent: Thursday, August 19, 2010 12:43 AM Subject: Re: [time-nuts] GPS pcb IDs?? Alan, You may want to compare to those: http://www.ko4bb.com/Timing/GPS_Pics/ If they do not match and you eventually find out what they are, please let me know and I will add them to my collection. That goes for anybody who has identified, clear pictures of GPS receiver boards, both sides preferably. Thanks in advance, Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Alan Melia alan.me...@btinternet.com Sender: time-nuts-boun...@febo.com Date: Thu, 19 Aug 2010 00:07:20 To: Time-Nuts measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] GPS pcb IDs?? Hi I have just acquired a couple of GPS receiver pcbs, ex Telcoms equipment. I know a lot of htese poards were discussed so time ago on the group. Does anyone recognise what they are and could point me at some intrormations please. I am afraid the flash has washed the the pics out a bit but hopefully there is enough detail to be recognised http://www.alan.melia.btinternet.co.uk/GPS/Trimble_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Trimble_lower.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_lower.JPG The Trimble pcb is 2.6 by 1.25in., and the Synergy is 3.15 by 1.6 in. Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS pcb IDs??
Thanks Christian, I have that doc but although I think it is probably relevant the outline of the pcb is totally different to the pcb I have though more like a number of M12 Oncores I have. Thank you for your interest, and help. Best Wishes Alan G3NYK - Original Message - From: Christian Riesch christian.rie...@omicron.at To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Friday, August 20, 2010 1:13 PM Subject: Re: [time-nuts] GPS pcb IDs?? -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Alan Melia Sent: Thursday, 19. August 2010 12:44 To: did...@cox.net; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS pcb IDs?? Hi Didier, the Trimble is a Resolution T (3.3v)user manual at the URL quoted by Stanley (Thanks again Stanley) The Synergy is Motorola UT+ Oncore (5v) and I am sure the manual for those is around somewhere but not had time to chase that yet. Alan, on the gpsd website you can find the Motorola Oncore Documentation: http://gpsd.berlios.de/vendor-docs/motorola/ Christian Please feel free to add these to your gallery...I may have some more when I get round to taking some photos Thanks and Best Wishes Alan G3NYK - Original Message - From: Didier Juges did...@cox.net To: Time-Nuts time-nuts@febo.com Sent: Thursday, August 19, 2010 12:43 AM Subject: Re: [time-nuts] GPS pcb IDs?? Alan, You may want to compare to those: http://www.ko4bb.com/Timing/GPS_Pics/ If they do not match and you eventually find out what they are, please let me know and I will add them to my collection. That goes for anybody who has identified, clear pictures of GPS receiver boards, both sides preferably. Thanks in advance, Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Alan Melia alan.me...@btinternet.com Sender: time-nuts-boun...@febo.com Date: Thu, 19 Aug 2010 00:07:20 To: Time-Nuts measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] GPS pcb IDs?? Hi I have just acquired a couple of GPS receiver pcbs, ex Telcoms equipment. I know a lot of htese poards were discussed so time ago on the group. Does anyone recognise what they are and could point me at some intrormations please. I am afraid the flash has washed the the pics out a bit but hopefully there is enough detail to be recognised http://www.alan.melia.btinternet.co.uk/GPS/Trimble_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Trimble_lower.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_top.JPG http://www.alan.melia.btinternet.co.uk/GPS/Synergy_lower.JPG The Trimble pcb is 2.6 by 1.25in., and the Synergy is 3.15 by 1.6 in. Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS pcb IDs??
Thanks Art that describes it faithfully and explains the differences. I am sure one of the guys will offer to host the information for the group. Thanks and Best Wishes Alan G3NYK - Original Message - From: Art Sepin a...@synergy-gps.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, August 20, 2010 9:27 PM Subject: Re: [time-nuts] GPS pcb IDs?? Gentlemen, What you have is a Motorola SL Oncore navigation receiver, R6 series model number, with timing firmware installed. These 8 channel receivers, slightly smaller than the UT+ but larger than the M12x receivers, were flashed with UT+ timing firmware and shipped to various telecom companies between 1999 and 2003. Unlike the Motorola VP, GT/GT+ and UT/UT+ receivers, the SL Oncore receivers are characterized by an RF Dam PC trace in place of the full metal shield covering the RF components. Most of the SL Oncore receivers we shipped were mounted in a full, shielded enclosure to operate in higher EMI environments encountered in telecom installations. An SL Oncore Engineering Notes document outlines the physical, electrical and environmental characteristics of this GPS receiver. A separate User's Guide for the SL was not published. The navigation firmware load is like the older GT+ and the timing firmware load is like the UT+. Therefore, the UT+ command/reply messages outlined in the GT+/UT+ User's Guide can serve as a reference to the timing messages available in the SL Oncore. Because of continuing requests, we will be updating our web site to include information on Motorola's legacy GPS receivers. In the interim, please let me know where I can e-mail the SL Engineering Notes so that anyone with interest can make reference to them. Engineering notes in electronic form are also available for the Basic Oncore, VP Oncore, GT+ UT+ Oncore and the M12 Oncore (but not M12+) - Thanks! Art Sepin Synergy Systems, LLC San Diego T (858) 566-0666 F (858) 566-0768 a...@synergy-gps.com -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Alan Melia Sent: Friday, August 20, 2010 6:37 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS pcb IDs?? Thanks Christian, I have that doc but although I think it is probably relevant the outline of the pcb is totally different to the pcb I have though more like a number of M12 Oncores I have. Thank you for your interest, and help. Best Wishes Alan G3NYK - Original Message - From: Christian Riesch christian.rie...@omicron.at To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Friday, August 20, 2010 1:13 PM Subject: Re: [time-nuts] GPS pcb IDs?? -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Alan Melia Sent: Thursday, 19. August 2010 12:44 To: did...@cox.net; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS pcb IDs?? Hi Didier, the Trimble is a Resolution T (3.3v)user manual at the URL quoted by Stanley (Thanks again Stanley) The Synergy is Motorola UT+ Oncore (5v) and I am sure the manual for those is around somewhere but not had time to chase that yet. Alan, on the gpsd website you can find the Motorola Oncore Documentation: http://gpsd.berlios.de/vendor-docs/motorola/ Christian Please feel free to add these to your gallery...I may have some more when I get round to taking some photos Thanks and Best Wishes Alan G3NYK - Original Message - From: Didier Juges did...@cox.net To: Time-Nuts time-nuts@febo.com Sent: Thursday, August 19, 2010 12:43 AM Subject: Re: [time-nuts] GPS pcb IDs?? Alan, You may want to compare to those: http://www.ko4bb.com/Timing/GPS_Pics/ If they do not match and you eventually find out what they are, please let me know and I will add them to my collection. That goes for anybody who has identified, clear pictures of GPS receiver boards, both sides preferably. Thanks in advance, Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Alan Melia alan.me...@btinternet.com Sender: time-nuts-boun...@febo.com Date: Thu, 19 Aug 2010 00:07:20 To: Time-Nuts measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] GPS pcb IDs?? Hi I have just acquired a couple of GPS receiver pcbs, ex Telcoms equipment. I know a lot of htese poards were discussed so time ago on the group. Does anyone recognise what they are and could point me at some intrormations please. I am afraid
Re: [time-nuts] Small quantity custom crystals
Mark to my inexpert eye that doesnt look like a very good overtone oscillator but I appreciate that it is slimmed down to keep the weight and size down, I can see why it is touchy. There is nothing to make the oscillator degenerate at the crystal fundamental. In fact it looks like a Pierce with a tuned circuit in the anode. If it goes off at the overtone my guess is that it by luck! But there are more clever people than me in this Group who may be more useful to you. Old fashioned crystals (lapped to frequency) used 5th OT up to just over 100MHz and the 7th and then 9th the blank was too fragile to go further. I believe modern micro machining techniqes where a thicker ring of quartz surrounds the resonator will allow a 5th overtone operation at 200MHz but you still have to make sure it doesnt go off at the fundamental or the 3rd .it may still transmit, but it will be off-channel and lower in power. Overtones are not harmonics.in radio anyway. Alan G3NYK - Original Message - From: Mark Sims hol...@hotmail.com To: time-nuts@febo.com Sent: Thursday, September 30, 2010 7:57 PM Subject: [time-nuts] Small quantity custom crystals I need to build some small tracking transmitters (using a circuit similar to http://www.jbgizmo.com/page4.html This circuit uses a fifth overtone crystal to get an output in the 216 to 220 MHz range. The circuit is rather finicky about the crystal and transistor... most don't work. Smaller and more rugged crystals are preferred. Does anybody know of a place that can make 1 off crystals in this range for a reasonable price. Many of usual suspects don't seem to be able to make crystals in that range. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Small quantity custom crystals
Hi Mark looking at the M15m article where the design seems to stem from suggests that the oscillator is NOT opertaing on 150 or 200 MHz but in fact 40 to 50 Mhz with a cheap crystal and the LC collector circuit is selecting the the 3rd or 5th harmonic (not overtone a common mis-apprehension) The pulsing is just an RC in the base bias where the high value of R wont allow the circuit to oscillate hence it takes no current until the C is charged up. My thought is a 200MHz overtone crystal could cost you $60, whereas a 50MHz 3rd OT will probably cost $20 and a cheap computer grade $2. The big difficulty will be getting cheap crystals on the right or anyway different enough frequencies. Crystals removed in rechannelling older 2-way radios may be a better source. I have hunders of these.unfortunately I am in the UK. Alan G3NYK - Original Message - From: Mark Sims hol...@hotmail.com To: time-nuts@febo.com Sent: Friday, October 01, 2010 10:18 PM Subject: [time-nuts] Small quantity custom crystals This type of circuit is NOT a free running oscillator. It is a type of blocking oscillator that generates a short, high powered ping every second or two. It is designed to be able to extract every bit of power out of the battery. It can run for over a month off of a couple of button cells, yet generate a signal detectable over a mile away while it is laying flat on the ground. The allowable frequency bands are at 216, 217, and 219 Mhz. Each unit must be on its own freq, hence the need for one-off custom crystals. Yes, it is a weird circuit and depends upon all sorts of unspecified parameters. The components have to be hand selected and matched. This is the price one has to pay for this sort of operation. --- -Build a free running Colpitts oscillator and get it tuned to the frequency you want. Then, insert the crystal in series with theemitter. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP/Dymek DY-5842
Dick did you ever try an unscreened loop ?? they should be just as good if not better at 60kHz. Alan G3NYK - Original Message - From: Dick Moore rich...@hughes.net To: time-nuts@febo.com Sent: Saturday, October 02, 2010 11:22 PM Subject: Re: [time-nuts] HP/Dymek DY-5842 I used to have one of these marvelous receivers and sold it. I still have the WWVB/60kHz shielded loop antenna that I made for it and although it is big, at about 30 x 30 x 2 or so, I believe it will ship FedEx or UPS OK. It's free to anyone who'll pay the shipping. It's made out of copper pipe and works quite well, and is tuned for the 5842 at 60kHz. Best, Dick Moore On Oct 1, 2010, at 3:50 PM, time-nuts-requ...@febo.com wrote: Message: 5 Date: Fri, 01 Oct 2010 16:34:57 -0600 From: ziggy9 zig...@pumpkinbrook.com Subject: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec DY-5842 VLF receiver? To: time-nuts@febo.com Message-ID: 990bd60b3c5d084910c10c8855912...@pumpkinbrook.com Content-Type: text/plain; charset=UTF-8 Fellow time-nuts: I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in conjunction with an external time interval counter to make a frequency comparison. So you would select WWVL for example, and use that as your primary standard for comparison to your local standard. It's got 5 crystals in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, WWVB). It works and I have the manual. The thing is, the interest in something like this is bound to be a bit narrow, so I thought I'd mention it here. So if there are any collectors, equipment museums, etc. that might be interested in this, please let me know. I'm a bit sentimental about this thing, it's sort of a bit of history, and from what I can tell, somewhat rare (doesnt make it worth anything though :). Since it's a bit of a curiosity, I'd like to pass it to someone that might be interested in it rather than just tossing it. I can always provide more details to anyone that wants them. Best regards, Paul Davis - K9MR -- Message: 6 Date: Fri, 1 Oct 2010 18:42:16 -0400 From: jmfranke jmfra...@cox.net Subject: Re: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec DY-5842 VLF receiver? To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: b7ea2d4ab6f34ab19da25cfdc85a6...@franke Content-Type: text/plain; format=flowed; charset=iso-8859-1; reply-type=original I am very interested. Do you have any images? John Franke WA4WDL Portsmouth, VA 23703 -- From: ziggy9 zig...@pumpkinbrook.com Sent: Friday, October 01, 2010 6:34 PM To: time-nuts@febo.com Subject: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec DY-5842 VLF receiver? Fellow time-nuts: I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in conjunction with an external time interval counter to make a frequency comparison. So you would select WWVL for example, and use that as your primary standard for comparison to your local standard. It's got 5 crystals in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, WWVB). It works and I have the manual. The thing is, the interest in something like this is bound to be a bit narrow, so I thought I'd mention it here. So if there are any collectors, equipment museums, etc. that might be interested in this, please let me know. I'm a bit sentimental about this thing, it's sort of a bit of history, and from what I can tell, somewhat rare (doesnt make it worth anything though :). Since it's a bit of a curiosity, I'd like to pass it to someone that might be interested in it rather than just tossing it. I can always provide more details to anyone that wants them. Best regards, Paul Davis - K9MR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Message: 7 Date: Fri, 01 Oct 2010 17:50:17 -0500 From: Brian Kirby kilodelta4foxm...@gmail.com Subject: Re: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec DY-5842 VLF receiver? To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 4ca665a9.1090...@gmail.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed You might consider contacting Dr. Ken Kuhn -- kennathak...@gmail.com check his HP museum at http://www.kennethkuhn.com/hpmuseum/ Brian Kirby KD4FM On 10/1/2010 5:34 PM, ziggy9 wrote: Fellow time-nuts: I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in conjunction with an external time interval counter to make a frequency comparison. So you would select
Re: [time-nuts] 60kHz Loop antenna
Thanks Dick, Ok with interference that close it would help. Shielding doesnt always provide much at these frequencies and can reduce the Q of the loop. Best Wishes Alan G3NYK - Original Message - From: Dick Moore rich...@hughes.net To: time-nuts@febo.com Sent: Sunday, October 03, 2010 6:56 AM Subject: Re: [time-nuts] 60kHz Loop antenna Alan, I did try a real half-a$$ed pile of wire and a tuning cap. My shop has fluorescent lights and I got a lot of noise. Once I built the shielded loop and got it lined up with east and a little south (I'm in Washington State), WWVB came in gang-busters. This was before I built a GPSDO or two and then got a TBolt. The shielded loop has just been sitting for years. Dick On Oct 2, 2010, at 3:42 PM, time-nuts-requ...@febo.com wrote: Message: 5 Date: Sat, 2 Oct 2010 23:40:52 +0100 From: Alan Melia alan.me...@btinternet.com Subject: Re: [time-nuts] HP/Dymek DY-5842 To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 015501cb6283$10071ad0$4001a...@lark Content-Type: text/plain; charset=iso-8859-1 Dick did you ever try an unscreened loop ?? they should be just as good if not better at 60kHz. Alan G3NYK - Original Message - From: Dick Moore rich...@hughes.net To: time-nuts@febo.com Sent: Saturday, October 02, 2010 11:22 PM Subject: Re: [time-nuts] HP/Dymek DY-5842 I used to have one of these marvelous receivers and sold it. I still have the WWVB/60kHz shielded loop antenna that I made for it and although it is big, at about 30 x 30 x 2 or so, I believe it will ship FedEx or UPS OK. It's free to anyone who'll pay the shipping. It's made out of copper pipe and works quite well, and is tuned for the 5842 at 60kHz. Best, Dick Moore On Oct 1, 2010, at 3:50 PM, time-nuts-requ...@febo.com wrote: Message: 5 Date: Fri, 01 Oct 2010 16:34:57 -0600 From: ziggy9 zig...@pumpkinbrook.com Subject: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec DY-5842 VLF receiver? To: time-nuts@febo.com Message-ID: 990bd60b3c5d084910c10c8855912...@pumpkinbrook.com Content-Type: text/plain; charset=UTF-8 Fellow time-nuts: I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in conjunction with an external time interval counter to make a frequency comparison. So you would select WWVL for example, and use that as your primary standard for comparison to your local standard. It's got 5 crystals in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, WWVB). It works and I have the manual. The thing is, the interest in something like this is bound to be a bit narrow, so I thought I'd mention it here. So if there are any collectors, equipment museums, etc. that might be interested in this, please let me know. I'm a bit sentimental about this thing, it's sort of a bit of history, and from what I can tell, somewhat rare (doesnt make it worth anything though :). Since it's a bit of a curiosity, I'd like to pass it to someone that might be interested in it rather than just tossing it. I can always provide more details to anyone that wants them. Best regards, Paul Davis - K9MR -- Message: 6 Date: Fri, 1 Oct 2010 18:42:16 -0400 From: jmfranke jmfra...@cox.net Subject: Re: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec DY-5842 VLF receiver? To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: b7ea2d4ab6f34ab19da25cfdc85a6...@franke Content-Type: text/plain; format=flowed; charset=iso-8859-1; reply-type=original I am very interested. Do you have any images? John Franke WA4WDL Portsmouth, VA 23703 -- From: ziggy9 zig...@pumpkinbrook.com Sent: Friday, October 01, 2010 6:34 PM To: time-nuts@febo.com Subject: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec DY-5842 VLF receiver? Fellow time-nuts: I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in conjunction with an external time interval counter to make a frequency comparison. So you would select WWVL for example, and use that as your primary standard for comparison to your local standard. It's got 5 crystals in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, WWVB). It works and I have the manual. The thing is, the interest in something like this is bound to be a bit narrow, so I thought I'd mention it here. So if there are any collectors, equipment museums, etc. that might be interested in this, please let me know. I'm a bit sentimental about this thing, it's sort of a bit of history, and from what I can tell, somewhat rare (doesnt make it worth anything though :). Since it's a bit of a curiosity, I'd like to pass it to someone that might be interested in it rather than just
Re: [time-nuts] 60kHz Loop antenna
The loop will be tuned (!) but hopefully to a freqency much above 60kHz by the inter-turn and turn to screen capacitance. Also hopefully this will be a low Q resonance and the phase frequency response at 60kHz should then be stable with ambient conditions. Interestingly a lot of the modern LF and VLF Off-air Standards use ferrite rod antennas and there are known problems with those, Quartzlock advise a air loop for critical requirements. Alan G3NYK - Original Message - From: Arthur Dent golgarfrinc...@yahoo.com To: time-nuts@febo.com Sent: Sunday, October 03, 2010 5:09 PM Subject: [time-nuts] 60kHz Loop antenna John-…”HP's loop for the 117A is not tuned, as I rember, but it is followed with a narrow band amp.“ Both the nuvistor and FET versions of the loop show capacitors across the loop winding to tune it. http://www.leapsecond.com/museum/10509a/ -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Radio based time stations
Hi Poul-HenningOh yes we did ! but the closed a long time ago. MSF was on 2.5, 5 and 10 Mc/s:-)) (It only hertz when I laugh) OMA similar HBG there may have been others. I seem to remember the HF stations took it in turns to transmit Alan G3NYK - Original Message - From: Poul-Henning Kamp p...@phk.freebsd.dk To: kd...@spamcop.net; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, October 05, 2010 12:34 PM Subject: Re: [time-nuts] Radio based time stations Lee Reynolds writes: Overall, we probably now have a quarter to a third of the SW time stations compared to those that that existed 20 years ago. I think too many radio-controlled alarmclocks have been sold for the remaning big VLF stations to disappear any time soon... Shortwave ? I can live without those, as far as I know we never really had any here in europe... Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 60 KHz Receiver
Hi Magnus its was a pity they didn't manage to communicate with some of my office collegues so as to to confirm the hand of the polarisation they were using though :-)) Goodhilly changed the feed for the other polarisation on the day of the first test, and it was a bit of a TV disaster. Lanion had a horn so had the same sytem. The horns are long gone except for the microwave background experiment but the Goonhilly Down dish called Arthur after a certain medieval king who spent his time whopping Danes :-)) I dont think the dish still carries traffic but it is capable, fully steerables are not needed for telecoms now. Arthur is now a historic monument so we do get some things right !! Alan G3NYK - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: time-nuts@febo.com Sent: Thursday, October 07, 2010 9:16 PM Subject: Re: [time-nuts] 60 KHz Receiver On 10/07/10 17:09, J. Forster wrote: Telstar was a BIG DEAL! There was even a pop song about it. Reading the Bell labs books on the Telstar project is very nice. Nice fold-outs on control-panels etc. They did spent a lot of time to engineer the whole thing. Their antenna setups that would track the high-dynamic movement due to the low orbit. Amplifiers was rubin-maser cooled with liquid helium... and stuff like that. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] RAPCO 1804 GPS Frequency Standard
It'll be your fault !! :-)) I was wondering about these but didnt know what they were like.I have a space in the rack.it 'ud better be good!! Alan G3NYK - Original Message - From: gandal...@aol.com To: time-nuts@febo.com Sent: Monday, October 11, 2010 10:13 PM Subject: [time-nuts] RAPCO 1804 GPS Frequency Standard Hi All Anybody fancy a Rapco 1804 GPS frequency standard for 70 GBP plus postage? Ebay item 320601939698 has eight available as a buy it now and available for worldwide shipping from the UK. These are 5MHz units using an HCD-66-SC ovened oscillator and mains powered in a 1U rack mount case. As far as I can tell the GPS module is a Trimble SV6 although I've also got one with what looks to be a retrofitted SV8 that does report 8 satellites via the Rapco serial port. Usual disclaimer applies, I have no vested interest whatsoever other than as a previously happy customer of this seller but am happy to recommend both him and these units. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Question about SoundCard stability?
Hi I do not follow al the techniques in detail but a lot of work has been done on soundcard sampling rates in the low frequency amateur radio groups where GPS locking is used to extract very weak signals from the noise in very narrow band widths. It has been found that some of the supposed standard samping rates are not exact divisors of the clock crystal and are achieved by a bodge in teh software but are regarded as close enough for some audio work The 11kHz rate is a particularly odd one but many of the 8kHz rates are quite a way off. There are several ways of locking the spectrogram software to a harmonic of the 1pps. If there is interest I may be able to dig out some URLs a quick check didnt yield what I wanted to show. Alan G3NYK - Original Message - From: jimlux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, October 15, 2010 2:26 PM Subject: Re: [time-nuts] Question about SoundCard stability? Ulrich Bangert wrote: Gents, I have already pointed to this paper http://ipnpr.jpl.nasa.gov/progress_report/42-121/121G.pdf for a number of times but appearantly it is still too less known or too less understood. Its appendix explains completely the necessary signal processing for frequency and phase extraction from a sampled sine using ALL samples. While the paper itself addresses this algo to radio frequencies it naturally works as well at audio frequencies. And, in any case, the RSA described in the paper is sampling an audio frequency beat note, so it's exactly applicable to what is contemplated here. As Ulrich comments in the rest of his post, the math is straightforward, the performance is all in the hardware execution. When measuring a gnat's eyelash, you need to worry about the bumps on the eyelash. Sound cards in PCs have all sorts of idiosyncracies. Consider them as a 10 bit/ 60dB sort of device: For instance, the sampling clock may be fairly stable, but it has interference from the processor clock on it, so you'll see spurs from that. There's leakage between channels. The low frequency response isn't very wonderful. etc. The folks doing ham software defined radios (in particular with the Flex-Radio boxes of the SDR1000 vintage a few years ago) spent a lot of time trying out different external sound interfaces: the performance of the interface directly affects the RF performance in the Flex direct conversion scheme. Unfortunately, a lot of the mail reflector archives aren't on-line, but there was a lot of empirical data that some dedicated people collected. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Does TIME-NUTS LIST-SERV allow CLASSIFIED For-Sale private advertisment?
You must also bear in mind that this a world-wide list. personally I would not be interested in sales of test equipment within the US, and I would not look here for equipment I might like to own. (Others in the Europe might) However, I would not object to a note that some gear is avilable and a detailed description or list can be viewed at... (maybe the trader site?) Many may seek to move unwanted or superceded gear to like minded collegues rather than be ripped off by a dealer on an auction site. This is to be encouraged in some part, but remember that I, and many others are members to share in the astonishing technical expertise available to all in the group. I remember that like OTs and discussions that go cosmic I always have the delete key. :-)) Thanks for a great communitylong may it flourish! Alan G3NYK - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: time-nuts@febo.com Sent: Monday, October 18, 2010 8:15 PM Subject: Re: [time-nuts] Does TIME-NUTS LIST-SERV allow CLASSIFIED For-Sale private advertisment? On 10/18/2010 06:31 PM, John Ackermann N8UR wrote: We've never had a hard-and-fast rule, but in general the community seems OK with (a) non-dealers making occasional postings about TF related items (i.e., excess or housecleaning items), and (b) commercial sellers making *very* occasional postings about unusual items. I think John agrees with me that occasional information on availability of DIY-related PCBs/kits (such as the PICTIC) created by fellow time-nuts is also OK. So is the case when people has come over a bunch of components which is hard to get. Periodic ads, or general we have the following items ads, would not be appropriate. At bottom, this is intended to be a technical discussion forum, and not a swap shop. We could have a separate time-nuts classified side-kick list, it would be much easier to direct other stuff there to keep clean. Just a thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New leap second
On the 4th July it (the Sun) was actually at its furtherst point from earth so we were getting less radiation .did your burghers take longer to cook ?? :-)) Alan G3NYK - Original Message - From: Chuck Harris [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, July 04, 2008 8:07 PM Subject: Re: [time-nuts] New leap second Bill Hawkins wrote: Chuck Harris wrote, Two leap seconds in as many years! It must be that global warming. Well, yes. The Earth expands from the heat, rotation slows, and we get another leap second - as we watch symptom after symptom occur while being unable to come to consensus on what to do. I say that we take up the issue with the Sun. Clearly it is also causing global warming on Mars. -Chuck Harris Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 74ac112 and 74ac164 sources and 200 Ohm resistors for frequency divider board?
Hi Dave Rapid Electronics in Colchester do SMBs the eaiest way to get 200 ohms might be 2 by 100ohm in series..though it wont fit a ready made 1206 size pcb :-(( www.rapidelectronics.co.uk or www.rapidonline.com is one they quote now I think both work. I dont think you will get 74ACs there though Alan G3NYK --snip I'm looking for 74ac164 and 74ac112 in SOIC (.15 wide) as the usual suspects (Farnell and RS Components) don't seem to stock these in UK :-( I found most of the other 74AC logic I want. I'm also hunting 200 Ohm 0.25W 1206 case thick film resistors. I can buy a reel of 5000 at about USD34 from RS Components, but don't really need quite as many as that!!! 300 ohm don't seem any easier :-( Yes, I know these aren't in the standard resistor sequence. I'll be using SMA rather than SMB connectors - they were easier to find (and I bought some on eBay). Cheers Dave Partridge ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Hameg HM8125 Time/frequency Standard
Hi Ian I dont know whether it works for that unit, but try the Hameg site. http://www.hameg.com/66.0.html There are almost complete manuals for all the units (well certainly the scopes!) You may find that there are no schematics in the English versionsdownload the German versions (which you may see are bigger files) and the are often schematics at the back of thesethe titles etc are also bilingual. Hope that helps Cheers de Alan G3NYK - Original Message - From: Ian Sheffield [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Tuesday, July 22, 2008 7:51 AM Subject: [time-nuts] Hameg HM8125 Time/frequency Standard Hello, Does anyone have a copy of a schematic or service manual for the down-converter for the Hameg HM8125 GPS frequency/time receiver? The receiver and display seems to be working fine, but the separate down-converter appears to have been modified with a capacitor blocking the DC power feed from the receiver and what may be a voltage regulator has been removed. The downconverter appears to do more than just shift frequency, as it has a TDA 1574 FM subsystem chip in it as well as the expected RF circuitry. Any help would be appreciated, or even if someone had a spare downconverter for sale.? These units do unfortunately, appear to be as scarce as hens' teeth. Thanks in advance, Ian Sheffield ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Hameg HM8125 Time/frequency Standard
You might try the UK agent who has been quite helpful on scope spares. [EMAIL PROTECTED] I can't remember the fellow's name now, but I bought several control knobs to refurb an HM1005 scope. He was very helpful though this adress is not the one on the back of the manuals! Alan G3NYK - Original Message - From: Ian Sheffield [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, July 22, 2008 11:43 AM Subject: Re: [time-nuts] Hameg HM8125 Time/frequency Standard Hi Alan, Tried that, and downloaded the operating manual a while back. Tried your tip and looked at the German version, but no luck either. Thanks for the suggestion though. Cheers, Ian. - Original Message - From: Alan Melia [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, July 22, 2008 10:50 AM Subject: Re: [time-nuts] Hameg HM8125 Time/frequency Standard Hi Ian I dont know whether it works for that unit, but try the Hameg site. http://www.hameg.com/66.0.html There are almost complete manuals for all the units (well certainly the scopes!) You may find that there are no schematics in the English versionsdownload the German versions (which you may see are bigger files) and the are often schematics at the back of thesethe titles etc are also bilingual. Hope that helps Cheers de Alan G3NYK - Original Message - From: Ian Sheffield [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Tuesday, July 22, 2008 7:51 AM Subject: [time-nuts] Hameg HM8125 Time/frequency Standard Hello, Does anyone have a copy of a schematic or service manual for the down-converter for the Hameg HM8125 GPS frequency/time receiver? The receiver and display seems to be working fine, but the separate down-converter appears to have been modified with a capacitor blocking the DC power feed from the receiver and what may be a voltage regulator has been removed. The downconverter appears to do more than just shift frequency, as it has a TDA 1574 FM subsystem chip in it as well as the expected RF circuitry. Any help would be appreciated, or even if someone had a spare downconverter for sale.? These units do unfortunately, appear to be as scarce as hens' teeth. Thanks in advance, Ian Sheffield ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.5.3/1565 - Release Date: 7/21/2008 18:36 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GPS shielding by power lines?
Hi all, in the process of setting up a GPS time standard for a Radio Astronomy facility (amateur) we installed a GPS receiver in a small cabin with a translucent roof, thinking that would not impede the GPS signal. After a lot of head scratching as to why we were not getting the performane we got at another site, we realised that the convenient position for the cabin was directly below a three phase 11kV power distribution line ( common UK rural electricity distribution system). We extended the cable and moved the antenna about 20 - 30 feet to the side of the line run, which was mounted on wooden poles at about 25 feet. In this position we immediately got a reliable fix. The fix and number of usable satellites degrades as we move nearer the lines. The thought was that there as interference arcing or corona noise from the line insulators, and a receiver (AM) was deployed to listen for what was expected to be a substantial wide band noise signalwe didnt hear one! We are now confused about what the effect is. The signal could not be screened by the wires which are about 3 feet apart, but they definite provide a cone of interference directly under the run. The experiment was later repeated with two further different GPS receivers and produced the same result. Has anyone seen this before? have you any idea of what level noise we should be looking for? I believe this is a wide signal so maybe an AM receiver is not the best choice The area is a rural, horticultural area (called market garden in the UK) We are obviouslt concerned to trace any noise sources in the vicinity of the Hydrogen line frequency at 1420MHz. Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS shielding by power lines?
Hi Dave, Ah I meant a 1600Mhz AM RX not a MW job the resuly is quite dramatic from seeing no usable satelites to seeing 10 to 12. The software we are running plots the tracks of the those sats seen so we can see that when seen even close to trees, foliage shielding is not a problem. I could post this plot over a number of hours it is very pretty, and shows clearly the northerly extent of the orbits very clearly. Thanks Magnus for thoughts on further tests. We are logging the NMEA sentences so most of that detail could be available. A job for a laptop I think. Alan G3NYK - Original Message - From: David Ackrill [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, August 10, 2008 8:30 AM Subject: Re: [time-nuts] GPS shielding by power lines? Alan Melia wrote: Hi all, in the process of setting up a GPS time standard for a Radio Astronomy facility (amateur) we installed a GPS receiver in a small cabin with a translucent roof, thinking that would not impede the GPS signal. After a lot of head scratching as to why we were not getting the performane we got at another site, we realised that the convenient position for the cabin was directly below a three phase 11kV power distribution line ( common UK rural electricity distribution system). Since the satellite signals are in the high UHF range, arround 1575MHz, the AM receiver test is not going to tell you alot about the noise at the frequency that the GPS receiver is using. So, even if you had detected any noise from the overhead lines, it might not have been proof that this was the cause of the problems. I find that the positioning of the antenna for a GPS receiver can be very touchy. You really need a good view to the horizon and, despite what you might see on simple presentations of the satellite positions, they do tend to be mainly in the southern sky when viewed from the UK. See http://www.guralp.com/articles/20060405-howto-gps-troubleshooting/print for details. The other effect that you may notice is that your 'good' position for the antenna isn't so good all of the time as the satellites appear to move round the sky and the signal strengths from each alters. Dave (G0DJA) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS shielding by power lines?
Hi Tom Brilliant I hadnt thought of the fields actually affecting the operation of the electronics! that is certainly something that might be interesting to check. I note there lines have three phase feeds but no neutral wire so they must use ground as the return path to any unbalance currents.(?) Thanks Alan G3NYK - Original Message - From: Thomas A. Frank [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, August 10, 2008 6:38 AM Subject: Re: [time-nuts] GPS shielding by power lines? Alan; I have no idea if this is a cause of your problem, but in some work I have done, I found that the high field strengths (electrostatic and magnetic) found under power lines can adversely effect electronic equipment that should otherwise be unaffected by the presence of power lines and their low frequency signals. there. --snip ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS shielding by power lines?
Hi Didier, thanks for that idea, yes they were all pucks all Garmin two intended for marine use and one was a old Garmin GPSIIplus with a mag puck. I have a Trimble Palisade that I have not got round to working on yet, but I understand that there are problems putting this version into NMEA mode...so will have to be careful. Thanks Alan G3NYK - Original Message - From: Didier Juges [EMAIL PROTECTED] To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Sunday, August 10, 2008 12:52 PM Subject: Re: [time-nuts] GPS shielding by power lines? Alan, I don't believe you have said what type of antenna you are using. If you are using a true timing antenna (Symmetricom, Trimble Bullet) I would expect little or no direct effect from the power lines, but if you are using a puck or other inexpensive commercial antenna (which have little or no filtering or shielding), you may well be affected directly by the field from the power line on the antenna itself. The Thunderbolt itself should have enough filtering to protect you from a direct effect, the Thunderbolt has been designed to be co-located with other equipment, particularly cell transmitters, so I would expect it to be fairly immune to stray fields. Didier KO4BB ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS shielding by power lines?
Hi David yes indeed and the qualify of the fix imporves as we move away at right angles to the linedespite some trees and a tall hedge on one side. Dramatic and quite repeatable. Alan G3NYK - Original Message - From: David McGaw [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, August 11, 2008 5:12 AM Subject: Re: [time-nuts] GPS shielding by power lines? You didn't say if you tried the antenna under the power lines but outside the cabin. What is translucent to light may not be to microwaves. David N1HAC . ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Austron 1250B
Hi Corby, my 1250a has an EFC connection on the rear panel (a bnc connector) I have some circuitry but not sure at present what suffix letter it refers to My 1250as have a 5MHz OCXO. Alan G3NYK - Original Message - From: corby d dawson [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Saturday, August 30, 2008 10:50 PM Subject: Re: [time-nuts] Austron 1250B Hi, I am playing with an Austron 1250B and I'd like to add a fine frequency adjust. The data sheet I have on the 1150 oscillator inside indicates that the EFC input is an option. Anyone have a schematic for the 1250B that shows how the 1150 is wired in. If no EFC on this unit I'll be getting rid of it. Thanks, Corby Dawson Click to make millions by owning your own franchise. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m6iSRbslUuv6eYSqQX4VKjWuK 9N7IRHgjWc9Dfez5DWUmBr/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Austron 1250B
Hi Corby and Nigel. I think I have a data sheet for the 1150 oscillator somewhere as well. I have an orphan 1MHz unit. The a definitely has the EFC on the rear and I recollect seeing a spec for the swing per volt. I seen to think it is quite fine and would be useful for GPS steering. Alan G3NYK - Original Message - From: corby d dawson [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Saturday, August 30, 2008 10:50 PM Subject: Re: [time-nuts] Austron 1250B Hi, I am playing with an Austron 1250B and I'd like to add a fine frequency adjust. The data sheet I have on the 1150 oscillator inside indicates that the EFC input is an option. Anyone have a schematic for the 1250B that shows how the 1150 is wired in. If no EFC on this unit I'll be getting rid of it. Thanks, Corby Dawson Click to make millions by owning your own franchise. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m6iSRbslUuv6eYSqQX4VKjWuK 9N7IRHgjWc9Dfez5DWUmBr/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Do any regulations or laws require tim e to be accurate within 'x' seconds?
- Original Message - From: Gretchen Baxter [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, November 03, 2008 5:03 PM Subject: [time-nuts] Do any regulations or laws require time to be accurate within 'x' seconds? Greetings, There are a lot of regulations that mandate synchronized time. But do any of these regulations or laws require time to be accurate within 'x' seconds? Such as, 'time much be synchronized within 5 seconds of GPS time. Thanx, Gretchen ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Checking accuracy of Rubidium standards
This is an interesting thread again.it may be similar to ones that have been discussed, but one or two furthur questions occur to me. I have a Montronics sytem that does comparisons by the multiply and mix process, and I find (also common to more modern Kethly systems) that the limitation is around a part in 10^10 where the noise on the phase output makes it not really usable (without a lot of averaging) being around or in excess of 90 degreees even with a couple of very good OXCOs. How does the 10G comparision avoid this problem with standard multipliers? I doubt you can go all that way with low-noise multipliers and have any useful signal left, or have I missed something. At present I use a phase meter (lock in amps can be quite good) at the MHz range and datalog the phase drift for several hours. I have determined that setting on the nose is not necessary (for my applications). It is more useful to know how far a source is off. How does the mix down compare with the seemingly more popular mix down and timestamp I understand from previous threads that this has more potential but might it also be as good even using simpler circuits that the NIST system. Thanks for all your efforts inthe background John. great reading material ! Alan G3NYK - Original Message - From: Jeffrey Pawlan [EMAIL PROTECTED] To: [EMAIL PROTECTED]; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, November 08, 2008 6:40 PM Subject: Re: [time-nuts] Checking accuracy of Rubidium standards On Sat, 8 Nov 2008, Randy wrote: I was wondering if it is worthwhile or even feasible to compare an LPRO Rubidium standard against a Z3801. Since their frequencies are probably going to be extremely close anyway it would seem some special method/equipment would be required for high precision. Suggestions? Randy, W7HR Port Orchard, WA The best way would be to compare the highest possible frequencies you can generate with these two sources. I use two 10GHz sources that are each phase locked to an external 10MHz reference. Then the 10GHz outputs can be compared using either of these easy methods: 1) look at the DC/IF output of a microwave mixer where the LO and RF ports are driven by the two 10GHz sources. Don't overdrive the RF input to a level that can burn out your mixer. 2) use a good microwave frequency counter to read one of the 10GHz outputs while driving the counter's 10MHz ext ref input with the 10MHz from the other 10MHz source. This is very fast but will only give you accuracy readings that are a function of the resolution of the counter plus the bounce of the last digit owing to sampling and triggering. 3) if you have access to a lab with one or two microwave synthesized signal generators, then you can apply the 10MHz sources to the ext ref inputs of each of these signal generators and then proceed as in 1) or 2) I have done comparison at 26GHz this way so I have a bit more resolution. 73, Jeffrey Pawlan WA6KBL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Why/when did cell towers switch to 15 MHz?
Some of the ex Telcom units I have seen have 10MHz Rb or OCXO (Datum or Lucent) and a 10 to 15MHz converter in a milled cover externallysome frequencies are more easily generated from 15MHz. Alan G3NYK - Original Message - From: [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, November 16, 2008 10:57 PM Subject: Re: [time-nuts] Why/when did cell towers switch to 15 MHz? Not exactly sure why they use 15 MHz, but a good buddy of mine who's a Verizon Wireless tech says 15 MHz it is. Mike there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PC run FFT
Neville there is a Fourier routine built in I have used it for time sequence analysis. It is not loaded by default. You may have to check the dropdown menus to load it in (at least that was what I needed to do, but I am mean and running an old Op-system :-)) ) Cheers de Alan G3NYK - Original Message - From: Neville Michie namic...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, December 20, 2008 9:50 PM Subject: [time-nuts] PC run FFT Hi, does anyone know of a fast fourier transform module or subroutine that could be run in XCEL ? Or a small program that could process a data set in a PC. It is a convenient way of handling data but I have not seen a FFT in the box of tricks. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Solstice question, about 5000 years ago
Hi Bill About 100 millenia of accumulated experience with probably the last 2 or three actually farming very successfully where you need to know about seasons. The Celts were a very civilised people (but their history was written by their conquorers!) and great traders even in those days. Flints were exported and later metals tin lead and copper, and even some gold. The Romans didnt beat us up for nothing !! It had to be worth the effort. GB was the granary of their western empire. Note Stonehenge dates from the same period or even earlier and has 10 ton stones which can only be found 100 miles away on the Welsh mountains.not just picked up near by! Mind you I dont expect the drummed the local Druid out of the time-nuts if he got it wrong by a day :-)) Alan G3NYK - Original Message - From: Bill Hawkins b...@iaxs.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Sunday, December 21, 2008 9:11 PM Subject: [time-nuts] Solstice question, about 5000 years ago The passage grave at New Grange, Ireland, is one of those astronomical wonders where the rising sun at winter solstice shines down a relatively long tunnel to shine on carved stone at the far wall of a chamber. We know that solstice has the shortest day and the longest night. How'd they know that? Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Astro-paleology or paleo-astronomy
Hi Magnus, I am sure I have at least one astro planetarium program somewhere (it doesnt get much use here) that will allow you to set the clock to 5000BC not GPS disciplined though :-)) I will have to check the detail. One was written by a good friend now deceased. Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lady Heather Update
Hi all, I am running an AMD Duron 700MHz running W98SE when run the program opens a DOS window but crashes the video monitor until the program is stopped with the escape key. So some of the problems may be with the monitor parameters which may not support the high res that a lot will be running even on 98. One solution might be to temporarily select a generic VGA ?? and the boot the program ?? But setting the display to 640 x 480 and 16 colours also gave a blank sccreen (the monitor didn't undestand the drive to it ) Alan G3NYK - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: Richard W. Solomon w1...@earthlink.net; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, January 31, 2009 6:31 PM Subject: Re: [time-nuts] Lady Heather Update Richard W. Solomon skrev: I tried it on my Compaq 486 running WIN98SE I get a black screen with Logoff on it and a couple of other lines that make no sense ? Who has the Rosetta Stone ?? I do not know... British Museum maybe? I tried to recompile in my Cygwin environment but with no luck, failed to compile. It seems to be beyond me... I know nothing about Windows... I just need to run the damn thing for some apps... Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS antenna installation problem
I am sure it is NOT a good idea to hand heavy cable like RG-8 from the N-type connector. What will hapen is that the cable will walk out of the connector and the centre pin will withdraw from the socket. This happens whilst the outer jacket stretches so there is no indiction there is a physical problem. This can happen very quickly but does depend on the strain put on the cable (Amateur Radio field-day experience !!) You should always loop the cable and take the strain off the connector totally. Take the cable down and remake it, add strain relief, and all will probably be well. Alan G3NYK - Original Message - From: Bill Hawkins b...@iaxs.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Sunday, March 01, 2009 8:05 PM Subject: [time-nuts] GPS antenna installation problem Group, My GPS time system consists of two Z3801A receivers with two HP cone antennas. I built a mast from plastic pipe (6 base to 2 arms) that is about 16 feet tall. The antennas are 4 feet apart, each 2' from the center of the mast. The mast rises from a deck and is fastened 8' up at the roof line. The mast sits on a 3/4 sheet of high density marine plastic fastened to the deck with stainless hinges so that the antenna can be folded away from the house and brought to the deck railing. The mast was put up in 2003. The antenna cables are each half of a 100' coil of RG-8U. Each cable is about half in the house and half outdoors. N connectors are soldered to both ends, so no adapters are used. The cables leave the house through a waterproof boat deck fitting and travel about 5' under the deck to the mast. There's a service loop to allow the mast to be lowered, then the cables rise unsupported through the mast pipe and branch out to the antennas, which support the weight of the cables. Oh, and the location is Minneapolis, MN, USA. The problem is loss of signal during cold weather. Last winter (07-08) I lost the signal from one antenna during a cold snap, but it came back a week or so later when it warmed up outside. This winter, I lost The North antenna on Nov 22 when the low was 15, and it didn't come back. Then the South antenna went away on Dec 24 with a -17 low and didn't come back. I'm still running on holdover. I suspect that it's not a good idea to hang 20 feet of RG-8 from an N connector without some kind of strain relief, but I don't know why that would be a cold weather effect. Perhaps the center conductor shrinks more than cable and its braid, and pulls the center pin out. There's definitely an open circuit, looking at the receiver end of the cable. There's no alarm from the Z3801. Any thoughts, comments or ideas? Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS antenna installation problem
Hi Hal, No, not as far as I know, and it is only intended to happen for a short (stub mast) distancce. The method I would use is to cable cleat two or three pieces of cord (use two or three cleats in series over 2 or 3 inches of jacket) on the jacket/sheath before dropping the cable down the tube. Support the weight of the cable on theseit will depend on your fixings etcyou may need to drill small exit holes or slots for the cord exit. Fasten the cords to take the weight, keeping the strain off the N-type brain clamp. Messy but essential. The used of adhesive shrink-sleeeving on the N-type body and the sheath my also give some extra support. The sheath and braid will stretch inder the weight whereas the inner and inner dielectic will not, this is what causes the pin whidrawal. I believe. How much cable will a connector support??none in my opinion!! The creep will just take longer! Practically maybe a couple of feet, it depends on the stiffness of the sheath material. Another thought is that if you are using heavy cable like RG-8, force it back up the mast an tie-wap it at the bottom as well. This wont work with RG-58 though. Richard, crimp connetxors dont solve the problem either because the weight is supported on the braid. They need adhesive shrink as well to provide jacket to connector-body support even in normal applications. I have repaired a lot of crimp connector systems that have failed this way, just under flexing and not any weight. I think it is what gives the system a bad name in some quarters. Alan G3NYK. - Original Message - From: Hal Murray hmur...@megapathdsl.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, March 01, 2009 11:50 PM Subject: Re: [time-nuts] GPS antenna installation problem Take the cable down and remake it, add strain relief, and all will probably be well. Is there a standard trick for how to do the strain relief when the antenna is setup to have the cable go up the inside of the mounting pipe? - Thanks everybody for all the roof/antenna hints from a week ago. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] delete
Helmut maybe you are not seeing it but it is the 2nd line attached below. Alan G3NYK - Original Message - From: helmut.im...@t-online.de To: time-nuts@febo.com Sent: Saturday, March 07, 2009 4:31 PM Subject: [time-nuts] delete Please delete me from the email distribution list. Thanks! Helmut ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran-C French Clocks
Hi Rob you might be able to get the official line from Peter Whibberly at Teddington. Alan G3NYK - Original Message - From: Rob Kimberley r...@timing-consultants.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Tuesday, March 17, 2009 7:58 PM Subject: Re: [time-nuts] Loran-C French Clocks UTC is the accepted international standard, but GMT appears to be steadfastly held onto by the UK (especially Government departments). I believe that GMT is actually by definition UTC_NPL, i.e. NPL contributes to UTC, but will have a small local offset as will all contributors. Feel free to correct me if I'm wrong here. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: 17 March 2009 19:20 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran-C French Clocks Steve Rooke skrev: Hi Magnus, Try this site out for size: http://wwp.greenwichmeantime.com/info/timezone.htm No. It just fails to make the distinction that I am asking for... Stockholm, Sweden is UTC+1h as normal time and UTC+2h as summer time, not GMT+1h and GMT+2h as indicated in the above site. Let me rephrase it properly so that it is understood: Does anyone has a collected list of the legally accepted time scale and offset, such that distinctions such as that between UTC and GMT is maintained? Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Rubidium is good for you...
I wonder what the FDA (Frequency Determining Association ??) has to say about that :-)) Alan G3NYK - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, April 17, 2009 11:15 AM Subject: [time-nuts] Rubidium is good for you... Fellow time-nuts, You find the strangest things when just surfing around ebay: Item number: 370158541330 Is it good for you??? Cheers, Magnus - not popping the lids... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Rubidium is good for you...
What radioactive decay ?? There are isotopes of most of these naturally occuring alkaline elements but most are very stable.you dont want the gas in your Rb lamp transmuting away !! There may even be nutritional benefits in snake oil :-)) Alan G3NYK - Original Message - From: Dave Carlson dgcarl...@sbcglobal.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, April 17, 2009 4:43 PM Subject: Re: [time-nuts] Rubidium is good for you... Since it's in a liquid, it must be in the hydroxide or some other ionic-compound form. Who can say as to any nutritional benefits? Anyone know whether the mild radioactive decay carries over to these compounds? Dave - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, April 17, 2009 3:15 AM Subject: [time-nuts] Rubidium is good for you... Fellow time-nuts, You find the strangest things when just surfing around ebay: Item number: 370158541330 Is it good for you??? Cheers, Magnus - not popping the lids... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Solartron 7081 ROMs
Or find the right prommer Peter :-)) Rom read correctly and image returned to David with the right checksum. Alan G3NYK - Original Message - From: Peter Vince pvi...@theiet.org To: bro...@pacific.net; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, April 29, 2009 8:50 PM Subject: Re: [time-nuts] Solartron 7081 ROMs I'm sure there was a message on this group a month or two ago, where the bottom line was to read the EPROMs with a slightly lower than usual voltage. Peter Vince On Tue Apr 28 15:40 , Brooke Clarke bro...@pacific.net sent: Hi Dave: I've read that there are some tricks to coaxing the data from memory chips related to reading them under different conditions. It's a lot of work, but it's possible to disassemble the code. That would allow it to be repaired. Have Fun, Brooke Clarke http://www.prc68.com David C. Partridge wrote: This is a call to anyone who has a Solartron 7081 and has saved a copy of their ROMs (if you haven't you may end up in the same boat as I am - the one that's up the creek without a paddle). One of the ROMs on my earthy processor board has died. It would appear that the ROMs in this 7081 were updated to a high level of firmware at some stage in its life as the total ROM image size is greater than that of a set that was copied by Bill Ezell from his 7081 even though his meter has a higher serial number (461) than mine (180). The ICs in question and the CRC16 checksums (in hex) for my ROM set are: IC430 3238 IC415 C5C0 IC414 1260 IC413 B958 IC412 ED50 If you have saved your firmware ROM images, and the checksums for your ROMs match these, I would be immensely grateful if you could send me the image for IC414 (the middle one of the three). If as a result of reading this message you feel impelled to save your ROM images and find your checksums match these ... Obviously if I can't find a good image of that ROM, I'll just install the older firmware, but one never knows. Cheers, David Partridge ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Cathodeon TCXOs??
Hi I wonder if anyone still has a datasheet/catalogue of Cathodeon products. This firm made crystals and oscillators and filters in the 1980 and 90s in Cambridge, England. (It is only 50 miles up the raod but I have not been able to find anyone who still has any knowledge of the products.) The units are FS5980/01 10MHz FS5951/315MHz I think the the 10MHz may be a TCXO,VCTCXO or even an OCXO, but the 5MHz does not have enough pins to be other than a TCXO. The spec would be useful (I think I have that from a previous query) but a pin-out is the vital information because none of the pins is common to the case, so it is difficult to work out the connections with an ohm-meter. Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Cathodeon TCXOs??
Thanks Roy, yes I know several peple who worlled for Pye / Philips, and the firm I was involved in was a dealer for a while in the 80s. I have some data but not on those units. I cant remember when Philips bought them but it was a kiss of death ! Thanks and Best Wishes Alan G3NYK - Original Message - From: Roy Phillips phill...@btinternet.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, May 24, 2009 9:53 PM Subject: Re: [time-nuts] Cathodeon TCXOs?? Alan The Cathodeon Company was part of Pye of Cambridge, which in turn became part of Philips. I understand that nothing has survived of the old Pye Group, so it may be difficult to obtain any new data. Roy - Original Message - From: Alan Melia alan.me...@btinternet.com To: time-nuts@febo.com Sent: Sunday, May 24, 2009 8:12 PM Subject: [time-nuts] Cathodeon TCXOs?? Hi I wonder if anyone still has a datasheet/catalogue of Cathodeon products. This firm made crystals and oscillators and filters in the 1980 and 90s in Cambridge, England. (It is only 50 miles up the raod but I have not been able to find anyone who still has any knowledge of the products.) The units are FS5980/01 10MHz FS5951/315MHz I think the the 10MHz may be a TCXO,VCTCXO or even an OCXO, but the 5MHz does not have enough pins to be other than a TCXO. The spec would be useful (I think I have that from a previous query) but a pin-out is the vital information because none of the pins is common to the case, so it is difficult to work out the connections with an ohm-meter. Thanks Alan G3NYK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Cathodeon TCXOs??
Hi Paul thanks for looking, the pin out for these beasties is the real info I am after. It is amazing how rapidly all the data has been lost..I am glad I saved some from the WPB myself. Thanks and Best Wishes Alan G3NYK - Original Message - From: Reeves Paul paul.ree...@uk.thalesgroup.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Tuesday, May 26, 2009 10:38 AM Subject: Re: [time-nuts] Cathodeon TCXOs?? I'm pretty sure that I have a Cathodeon filter/osc catalogue at home (work reference material relocated due to constant 'downsizing' of storage space by my employer - everything is on the internet); I'll check up on it tonight. Paul G8GJA -Original Message- From: Alan Melia [mailto:alan.me...@btinternet.com] Sent: 24 May 2009 20:12 To: time-nuts@febo.com Subject: [time-nuts] Cathodeon TCXOs?? Hi I wonder if anyone still has a datasheet/catalogue of Cathodeon products. This firm made crystals and oscillators and filters in the 1980 and 90s in Cambridge, England. (It is only 50 miles up the raod but I have not been able to find anyone who still has any knowledge of the products.) The units are FS5980/01 10MHz FS5951/315MHz pruned! ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sound Cards for locking to GPSDO 10 MHz references
I have seen it talked about (around the LF fraternity, but generally they are stable enough there and just need calibation) a lot but not accomplished yet. How about injection locking the on board oscmaybe gating the feedback with the referencenote I havent tried this? Another technique I have used to shift logic-block oscillators is to vary their supply voltage, they will oscillate from around 3v to well over 5.5v that might enable you to phase lock it using a variable regulator to vcxo to crystal?? Alan G3NYK - Original Message - From: Rex Moncur rmon...@bigpond.net.au To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Monday, June 01, 2009 10:59 PM Subject: [time-nuts] Sound Cards for locking to GPSDO 10 MHz references Hi all Does anyone have any experience of locking a USB external soundcard to a GPSDO 10 MHz reference. I am interested in advice on any good quality soundcards that can be readily locked to either 10 MHz or if necessary to some other frequency that we can derive from a GPSDO source. I have done some tests with the SignalLink soundcard that uses a Texas Instruments PCM2904 chip and requires a 12 MHz lock frequency. This requires some cutting of tracks to remove the internal oscillator feedback and insert the locking frequency. 12 MHz is readily derived from 10 MHz but I have not been able to get it to lock. The Texas instruments data sheet suggests that it is possible to use an external refernce but also says this is not recommended. With this expereicne I would rather find a sound card that is designed for external locking that does not require the cutting of tracks. For info the purpose of this request is that we are looking at using very narrow bandwidth modes at less than 1 mHz for light wave communcation. To date using LEDs and cloud reflection we have worked over 200 km with WSJT but we should be able to do 20 dB better if we can get down to milli-Hz bandwidths (at the expense of spending all night to complete a QSO). Our expereince to date is that standard sound cards are just not stable to better than 5 milli-Hz at 1000 Hz which should be readily solved by GPS locking let us get down to sub milli-Hz levels. Rex VK7MO ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
