Re: [time-nuts] Terrestrial GPS

Hi But, by their nature, not useful for timing or precision navigation. They are simply a solution to the “feed you coupons at the mall” issue. Since they run as an independent system (they have their own ID’s) the direct “pollution” issue on a GPSDO is eliminated. You still have the

Re: [time-nuts] Need a Watch Recommendation

rom a trusted 1PPS source. > > So now all that's needed is an alternate way for trimming the watch's > frequency > without opening the case. There must be a way... > > Dana > > > On Thu, Mar 15, 2018 at 8:13 AM, Bob kb8tq <kb...@n1k.org> wrote: > >> H

Re: [time-nuts] Need a Watch Recommendation

Hi > On Mar 15, 2018, at 1:33 AM, Dana Whitlow wrote: > > I concur with Bill. And even if one keeps tabs on the current watch error, > as is the usual practice by celestial navigators, once that error reaches > or exceeds more than a minute the process frankly gets more

Re: [time-nuts] Need a Watch Recommendation

Hi Yes, but will it display TimeNuts emails on the face of the watch? Better hope it’s a top poster it does :) …. scrolling through a lot of text is sort of non-functional on the Apple Watch. Bob > On Mar 14, 2018, at 9:58 PM, Jean-Louis Oneto wrote: > > The half dial in

Re: [time-nuts] Terrestrial GPS

emont most frequently > shows up as the "closest store" when I am looking at (for example) hardware > store web sites. > > Jeremy > N6WFO > > > On Wed, Mar 14, 2018 at 10:15 AM Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> WiFi based loca

Re: [time-nuts] Terrestrial GPS

Hi WiFi based location can be pretty good or it can be a real joke. It all depends on how good the database happens to be and how many stationary WiFi setups you can “see”. I’ve had it pop up with locations that are off by many miles. ISP’s feed you IP addresses via DHCP and the “on net”

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger --> GPS Issues

Hi > On Mar 12, 2018, at 9:54 AM, Peter Reilley wrote: > > Reading this paper makes one wonder if there are other improvements that > can be made to increase the robustness against jamming, software bugs, solar > events > or hostile attacks to the GPS system > > A

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi If you pick the “right” STM board, it can handle processing up around a megasample. It’s internal ADC’s are more of an issue than the sample rate. You can only do just so well on harmonics with a 12-ish bit ADC. Even if you go crazy and get one with a display, they still are pretty cheap.

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi Cute !! It certainly beats firing up an R-392 to see if you can get a tick from WWV… Bob > On Mar 11, 2018, at 5:42 PM, Tom Van Baak wrote: > >> “Back in the day” we used WWV and the kitchen clock for that sort of thing…… > > Bob, > > Yes, not much has changed. I

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

ly fun project. Much of > what you ever need to know about time & frequency metrology can be done by a > student with $10 in parts and a 60 Hz outlet. > > /tvb > > p.s. Yes, it's very early here on the west coast, but I had to check how > badly my WWVB clocks handled D

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi So, how good is “good enough?”. My first attempt ran a counter with a 1 us period resolution. (remember, it was tube based …). That turned out to be major overkill in terms of line frequency measurement. 60.123 Hz is doing pretty well in terms of line frequency. Even to get that level, you

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi The most basic question is - what do you have already? My first adventure with line monitoring was with a vacuum tube based counter. It was what I just happened to have. One basic need is something to monitor against. GPS is a pretty cheap option if you have nothing already. Rather

Re: [time-nuts] GPS L2 CNAV health reporting changes

Hi The Trimble empire here (NetRS’s and NetR8) seem to be reasonably happy with everything. I haven’t dug into any of the data. They all show L2C tracking along like normal. Bob > On Mar 8, 2018, at 9:23 PM, J. Grizzard wrote: > > I got a message from the

Re: [time-nuts] Ultra low power RTC

Hi > On Mar 7, 2018, at 6:33 PM, Mike Cook <michael.c...@sfr.fr> wrote: > > >> Le 7 mars 2018 à 11:10, Attila Kinali <att...@kinali.ch> a écrit : >> >> On Tue, 6 Mar 2018 21:57:32 -0500 >> Bob kb8tq <kb...@n1k.org> wrote: >> >>&g

Re: [time-nuts] Ultra low power RTC

Hi Ok, so energy harvesting from Lazy Bob in his arm chair makes a button cell look like a giant power source ….. You likely aren’t going to win any ADEV competitions with that oscillator. They did go to a *lot* of effort to squeeze out that last nano watt. Bob > On Mar 7, 2018, at 11:47 AM,

Re: [time-nuts] Ultra low power RTC

Mar 2018 08:27:00 -0500 > Bob kb8tq <kb...@n1k.org> wrote: > >> Since we don’t often *need* the smallest cell made *and* we’re probably >> talking lifetime of the cell….. does 22 na vs 33 na matter? > > Not really. It starts to matter when you are spac

Re: [time-nuts] Ultra low power RTC

Hi Since we don’t often *need* the smallest cell made *and* we’re probably talking lifetime of the cell….. does 22 na vs 33 na matter? …. hmmm …. CR2032 ( which is the smallest I would use) is rated at 0.22 AH. A nano amp for a year is about 8 uA hours a year. So 30 na for 20 years is

Re: [time-nuts] HP 107BR Ski Question

Hi The oscillators were tested and sorted at the end of the manufacturing line. Everything got checked for aging. It’s not clear that everything got detail tested for ADEV. The suspicion is that they did enough ADEV to get the few tight(er) spec units they needed. Next layer is that these

Re: [time-nuts] Ultra low power RTC

Hi Assuming you are going to run it off a battery. What’s the self discharge rate on a reasonable battery? Bob > On Mar 6, 2018, at 8:34 PM, Attila Kinali wrote: > > On Tue, 6 Mar 2018 22:59:34 + > Mark Sims wrote: > >> Sparkfun is selling an

Re: [time-nuts] My Favorite Watch

Hi Most (as in the center of the distribution) afordable watches are calibrated to run fast. There is info on this in the archives. A pretty typical target is 10 seconds a month. Yes, we used that as a target back in the 70’s but it’s still pretty common. You have to get lucky to find one

Re: [time-nuts] u-blox F9

Hi Looking at the press release, this is sort of the next step in the process that got us the NovaTel GPS units on eBay as ex-Uber surplus. If they can come up with a $1,000 board that replaces the NovaTel $5,000 unit, they have a product …. Will we see a $100 LEA-9T with the chip in it? Only

Re: [time-nuts] Z3801A OCXO manual trimming

Hi Assuming you can break the EFC lead to the OCXO, you aren’t going to damage anything inside by feeding the EFC line with +/- 5V. If you are going to tear open the OCXO, the line will need to be pulled anyway. Without knowing what they drive the EFC line with, it’s hard to know if the

Re: [time-nuts] Z3801A OCXO manual trimming

Hi The control range should be +/- 5V if I remember correctly. If it’s not, the only other standard would be 0-5V. There is zero logic in running a wider swing mod to an OCXO at a lower EFC range. It indeed sounds like the DAC has trouble. Bob > On Mar 6, 2018, at 1:24 AM, Mark Sims

Re: [time-nuts] Z3801A OCXO manual trimming

Hi Either tear into the OCXO or go shopping for a new(er) GPSDO. The Z38xx devices all had a lot more in common with each other than they did differences. The OCXO design changed from the 10811 to various more modern designs. The disciplining process seems to have remained pretty much the same

Re: [time-nuts] WWV or Net Clock controlled oscillator

Hi A very normal way to get the 60 Hz into the clock chips is to pull it off of something like the 24V transformer winding. They run through a resistor over to a limiter circuit to turn the sine wave into a square wave. That square wave heads into the input pin on the clock chip. Some “quality

Re: [time-nuts] Need a Watch Recommendation

Hi > On Mar 5, 2018, at 1:38 AM, Don Murray via time-nuts > wrote: > > Hello Time Nuts... > > > > After 6 years of no troubles, in sync with WWV any > hour of the day, flawless transfer between > standard and daylight time my Stauer Titanium > Atomic wristwatch bite

Re: [time-nuts] Z3801A OCXO manual trimming

Hi > On Mar 4, 2018, at 10:30 PM, Joe Hobart wrote: > > > Mark, > > When I press "D" Lady Heather replies: > > Manual disciplining not supported by this receiverpress ESC > > > Questions about the Z3801A: > > Does the oscillator have an adjustment? If so, is this

Re: [time-nuts] While we are talking about Z3801's

Hi Basic troubleshooting: Check the regulator output voltages and repair as needed. Basic serial troubleshooting: Bring up a terminal program, loop back the serial with a jumper, see if you have a connection. If you do, issue basic commands, see what happens. Switch to likely baud rates

Re: [time-nuts] LT1016 as a pulse shaper...

Hi Having tried to do these measurements a lot of ways ….. the TimePod makes it *very* easy. The ability to get phase noise and ADEV “all at once” is part of it. The ability to handle a wide range of input levels with minimal degradation is a also part of the why. The software makes it easy

Re: [time-nuts] LT1016 as a pulse shaper...

Hi The “best” way to measure phase noise will always be a “that depends” sort of thing. One pretty darn good way to check noise on any amplifier is to use something like a TimePod. You use a power splitter and a pretty good source. First you check your TImePod (or whatever) for floor. You

Re: [time-nuts] Z3801A OCXO manual trimming

Hi > On Mar 4, 2018, at 1:13 PM, Joe Hobart wrote: > > My Z3801A failed about a year ago (there was a warning the electronic > frequency > control was nearing a limit). > > Symptoms (most from GPS Control and Lady Heather: > > Frequency about 1E-8 low > > Time Invalid

Re: [time-nuts] Z3801A OCXO manual trimming

kled it yet, figuring I'd have to dismantle the whole > thing. Certainly troubleshooting a non-operating heater would be much more > pleasant. > > Thanks for that insight. > > Tom Holmes, N8ZM > > -Original Message- > From: time-nuts <time-nuts-boun...@febo.com&g

Re: [time-nuts] 50 ohm drivers

Hi We have gone over CMOS 50 ohm line driving a bunch of times. Check the archives for all of the various opinions. A quick summary: If you are driving CMOS, the output swing does not have to hit 99% of the supply. You can do a pretty good job with gates in parallel and no source termination.

Re: [time-nuts] LT1016 as a pulse shaper...

Hi If you are simply dealing with 10 MHz sine waves (as many of us are). — and — It’s a “matched” application ( = you know the level / the source and converter are tied together) — and — You don’t mind an L network to match increase the Vpp when it goes to the gate — and — Once the

Re: [time-nuts] Z3801A OCXO manual trimming

Hi First off some basics about OCXO’s. In a single oven design, you have a heater that warms up the entire crystal and the guts of the oscillator. It is on all the time and it gets things up to a temperature that makes sense for a given crystal. It can be adjusted based on manufacturing data

Re: [time-nuts] Microsemi up for sale?

Hi There’s a big chunk of sales under the “not semiconductor” side of Microsemi. It may not be big compared to an $8 billion sell price, but it’s not a trivial part of the company. Exactly what happens to things like the 5071 … we’ll see ….. How the sales policies of one or the other

Re: [time-nuts] Setting Z3801 date

Hi > On Mar 2, 2018, at 5:05 PM, Hal Murray wrote: > > Thorbjørn Pedersen said: >> Try this: >> Disconnect antenna. >> Power off / power on. >> Set date correctly. (You have the commands?) >> Connect antenna. >> Let it survey and stabilize > > That's what I

Re: [time-nuts] Efratom 105243-003 10MHz OCXO

Hi Pretty good bet that if it’s a 100K termination it’s a square wave output. The highest impedance you typically see on a sine wave is about 1K ohms. Even that is pretty rare on OCXO’s. Bob > On Mar 2, 2018, at 2:07 PM, David C. Partridge > wrote: > > Does

Re: [time-nuts] FRK

Hi Judging from the date codes on some of the parts, I’d guess that your FRL-L is from 1982. I’m only looking at a few parts that came through well enough in the picture to read (and that have what look like rational date codes …). Bob > On Feb 27, 2018, at 5:30 AM, Attila Kinali

Re: [time-nuts] Allan variance by sine-wave fitting

oila, that noise went away. Makes > sense when you think of the power variations associated with a blinking > incandescent lamp. > > /tvb > > - Original Message - > From: "Bob kb8tq" <kb...@n1k.org> > To: "Tom Van Baak" <t...@leapsecond.co

Re: [time-nuts] Allan variance by sine-wave fitting

Hi One of the TimePods that I had access to in the past was particularly good at telling you it was sitting on top of a power transformer. It didn’t matter a lot which instrument the power transformer was in. For some weird reason it was a good magnetometer at line frequencies. I never bothered

Re: [time-nuts] Beware the Casio WaveCeptor analog watch

Hi I’ve had the Citizen “Atomic” analog watches for quite a few years. The solar powered versions have gotten a bit better over the years. They nave never had a “hand slip” problem that I have noticed. Bob > On Feb 25, 2018, at 6:52 PM, Skip Withrow wrote: > > Hello

Re: [time-nuts] Replacement Backup Battery for 5065A?

Hi One very practical option: Pull the battery and don’t replace it. When the unit next comes out of storage, run it on a very normal UPS. The battery was a fine idea back in the era when this gear was newly designed. These days, the better option is an external “bulk” backup. If you are going

Re: [time-nuts] Replacement A9 boards for the HP 5065A

Hi Teflon is the traditional “best of the best” for integrator caps. Simply finding any plastic cap (other than a motor start device) up around 5 uf is not that easy these days. As mentioned by PHK, being sure it is what it’s supposed to be …. good luck. Bob > On Feb 24, 2018, at 6:45

Re: [time-nuts] Curious, how many t-nuts have 5065A

Hi The “pickup only” part of the deal would be a bit of an issue for some of us :) Bob > On Feb 24, 2018, at 5:46 AM, George Atkinson via time-nuts > wrote: > > There is one on UK ebay at the moment but its not being given away. From the > one partial photograph it looks

Re: [time-nuts] Curious, how many t-nuts have 5065A

Hi Well, if anybody else is “giving away” 5065’s I’d certainly be willing to “accept” one :) Bob > On Feb 23, 2018, at 10:25 PM, Pete Lancashire wrote: > > Wow, don't know why but more than I expected. I no longer do, but if the > person who I gave it to wants and is

Re: [time-nuts] HP 5065A super

Hi > On Feb 23, 2018, at 6:17 PM, jimlux <jim...@earthlink.net> wrote: > > On 2/23/18 1:33 PM, Bob kb8tq wrote: >> Hi >>> On Feb 23, 2018, at 4:23 PM, Attila Kinali <att...@kinali.ch> wrote: >>> >>> Hoi Bob, >>> >>>

Re: [time-nuts] HP 5065A super

Hi > On Feb 23, 2018, at 4:23 PM, Attila Kinali <att...@kinali.ch> wrote: > > Hoi Bob, > > On Thu, 22 Feb 2018 21:58:09 -0500 > Bob kb8tq <kb...@n1k.org> wrote: > >> The same nickel plating effect gets into a lot of things. If you are >> sho

Re: [time-nuts] Chinese made eBay antenna breakdown.

HI > On Feb 22, 2018, at 8:46 PM, John Green wrote: > > I didn't mean to imply that all Chinese made products are garbage. But, > some of them are. And, has been said, that is because people want to pay > the absolute lowest prices for stuff. The company I recently retired

Re: [time-nuts] HP 5065A super

Hi The same nickel plating effect gets into a lot of things. If you are shopping for very low IMD connectors, nickel plating is out. Things get non-linear (to a very slight degree) when it is present. If -180 db is the goal for those spurs, you might only hit -120 db with the nickel

Re: [time-nuts] Teardown of Chinese made eBay GPS antenna.

India > On Feb 22, 2018, at 5:37 PM, Van Horn, David > wrote: > > > "Some of you are to young to remember when Javanese products were considered > junk same storyBert Kehren" > > I've lived through Japan, Taiwan, and now China. Who's next?  > > >

Re: [time-nuts] Teardown of Chinese made eBay GPS antenna.

Hi As mentioned in another post, the part does claim to have thermal limit built in. They appear to pulse test them at 150 ma and 16V so there is indeed *something* that would suggest operation at 12V would be ok. I’d guess that the thermal regulation spec applies up to 16V and past that you are

Re: [time-nuts] HP 5065A super

Hi The control loop (of which A9 is a part) ultimately locks the OCXO in the 5065 to the Rb transition. Gain in the control loop suppresses the noise of the OCXO, making it’s ADEV better than it would have been stand alone. Ok so far? Bob’s not off the tracks (yet)? The various processes

Re: [time-nuts] LED instead of discharge lamp for Rb vapor cell standards

Hi > On Feb 22, 2018, at 8:22 AM, Attila Kinali wrote: > > On Wed, 21 Feb 2018 18:10:17 + > "Poul-Henning Kamp" wrote: > >>> So the Rb85 "notch" filter might not get rid of all the unwanted light >>> and some of this might depopulate the excited

Re: [time-nuts] LED instead of discharge lamp for Rb vapor cell standards

Hi There are a number of papers on LED / Laser excitation of Rb cells (and other gas cells). They go back quite a ways. The gotcha (as pointed out in PHK’s post) is that you need to stabilize the LED source. Doing that is a bit complex. Doing that so that the result beats a gas lamp is a bit

Re: [time-nuts] The "NAKED" 5065A optical unit

Hi Indeed very cool pictures. If the lamp is like most gas bulb lights, there is indeed a “strike voltage” required to get things going (or an RF excitation). There inevitably is some temperature dependence as well. A constant current driver might be the better bet. Bob > On Feb 20, 2018, at

Re: [time-nuts] Looking for some Frequency Electronics info....

Hi If it works like the unit that replaced it, it has a level detect on the external input that rejects signals below some threshold. It either locks up to the internal standard or to the external input. All of the outputs are in the 7 to 13 dim range when operating. The fault circuit looks

Re: [time-nuts] Rubidium for HP 53131A

Hi Be careful about air flow. Those counters have heat issues even in the stock configuration. The Rb is a bit of a power hog so it heats up as well. Not saying it won’t work, only that you need to be sure the air is moving in the right places. Bob > On Feb 19, 2018, at 4:18 PM, Skip Withrow

Re: [time-nuts] Symmetricom 58532A GPS Antenna : Launch3 Surplus

Hi One of the other variables in all this is the type of coax you use. The “best stuff” is flooded with silicon goop that is an absolute mess to deal with. It also will have a jacket on it that withstands UV better than the typical stuff. You may or may not need the UV protection, but you get

Re: [time-nuts] GPS Talking Clock

Hi > On Feb 17, 2018, at 11:01 PM, Nick Sayer via time-nuts > wrote: > > It’s been a while since I’ve posted here, but I’ve had a bunch of irons in > the fire. I’m working on adapting my GPSDO to the ECS ECOC-2522, which the > manufacturer claims has a short term ADEV in

Re: [time-nuts] eBay GPS antenna test.

Hi I think you probably will have to move up to around $500 or so (and still shop pretty hard) to find a Zephyr Geodetic 2 in excellent condition. A Novatel 703 Pinwheel would also be on the list of things to watch for. If you find a proper (L1 / L2 / L5 ) GNSS receiver with a pps out in

Re: [time-nuts] Hemisphere Antenna PCB

Hi I think I’d wait for the next batch of “new old stock” telecom L1 only GPS antennas to show up. I’d bet they will be roughly the same price. At least with them you also get the enclosure. They do show up in various conditions at various prices:

Re: [time-nuts] eBay GPS antennas

that said, still not encouraging. Bob > On Feb 16, 2018, at 2:49 PM, Gary E. Miller <g...@rellim.com> wrote: > > Yo Bob! > > On Fri, 16 Feb 2018 13:47:24 -0500 > Bob kb8tq <kb...@n1k.org> wrote: > >> Reports to date on Glonass have not been encouraging. >

Re: [time-nuts] eBay GPS antennas

Hi A full blown choke ring antenna is a pretty big heavy gizmo. That said, yes indeed, some shipping charges are insane. Bob > On Feb 16, 2018, at 1:51 PM, Wes wrote: > > On 2/16/2018 11:31 AM, Stewart Cobb wrote: >> ... >> >> For example, any AeroAntenna whose part

Re: [time-nuts] eBay GPS antennas

Hi Well, the interesting point about Glonass timing is that it is independent of the GPS empire. Galileo is another independent time source. Running a GPSDO linked to each one would let you inter-compare the time from each of them. Indeed I would *guess* that Galileo would do pretty well.

Re: [time-nuts] Furuno GT-8031 breakout board

Hi Even more exciting, some of the “M12 like” devices are close, but not exact copies of the M12 command set. Your GPSDO may be fine with the differences on this device, but not so happy with the differences on some other device. Bob > On Feb 16, 2018, at 12:50 PM, Mark Sims

Re: [time-nuts] eBay GPS antenna test.

e- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob > kb8tq > Sent: Tuesday, February 13, 2018 12:04 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] eBay GPS antenna test. > > Hi > > >> On Feb 13, 2

Re: [time-nuts] eBay GPS antenna test results.

. Bob > On Feb 15, 2018, at 9:13 AM, jimlux <jim...@earthlink.net> wrote: > > On 2/15/18 6:04 AM, Bob kb8tq wrote: >> Hi >> There are a number of reasons to believe that these antennas are worse >> than the typical “telecom GPS” antenna for L1 only duty driving a TB

Re: [time-nuts] Team of physicists repeats tvb Project GREAT

Hi > On Feb 15, 2018, at 9:03 AM, jimlux wrote: > > On 2/14/18 6:51 PM, Tim Lister wrote: >> On Feb 14, 2018 19:47, "Chris Caudle" wrote: >> On Wed, February 14, 2018 7:06 pm, jimlux wrote: >>> At substantially more expense, and with an experimental

Re: [time-nuts] eBay GPS antenna test results.

ter as a Symmetricom 58532A antenna ore the puck head > variant? > > If yes I would give it also a try but the shipment time from goods from china > are very high. Here to Germany there are timeframes from four to eight weeks > normal. :( > > But the price > - >

Re: [time-nuts] eBay GPS antenna test.

what. The seller *does* matter when you buy this stuff. That’s true no matter what you are getting. No matter how good they are, problems do come up. The question is always how well they address them. We tend to dump pretty hard on these guys. I’m not sure that’s always warrantied. Bob > &

Re: [time-nuts] eBay GPS antenna test.

Hi That can be a bit harder if the labels are all in Chinese. Maybe posting pictures of the label? That way those (not I) who can read Chinese might spot something that allows a search to proceed. Bob > On Feb 13, 2018, at 11:06 AM, Clint Jay wrote: > > Sounds like a

Re: [time-nuts] eBay GPS antenna test.

Hi China does a lot of things through a marketplace process. Lots of guys with piles of this or that. Any sort of product you get in (to them) small volume likely goes through this kind of arrangement. Buying OCXO’s and other timing gear is every bit as vulnerable to the “this one today,

Re: [time-nuts] eBay GPS antenna test results.

Hi Sitting here casually reading the data sheets for some of the modern Trimble survey receivers - they have gone to 7.2V (just below your 7.5V trigger point) as an antenna supply voltage. Who knows what that might imply relative to this antenna. Bob > On Feb 11, 2018, at 12:44 PM, John

Re: [time-nuts] eBay GPS antenna test results.

Hi Well, good news / bad news I guess. The seller is at least responding to your input. They also did not come back with something about “there is no voltage spec”. It’s quite possible that they are the 5th person in a chain of sellers and a substitution got made (unknown to them) at seller 3.

Re: [time-nuts] eBay GPS antenna test results.

Hi Ok, the antenna in the pictures on the listing *does* have labeling in English and it sure looks like it says 3.3 to 18V on the antenna. Certainly you have (and the rest of us may soon have) a case for “not as shown” in terms of what you got (and we get). Bob > On Feb 9, 2018, at 9:31 PM,

Re: [time-nuts] Symmetricom 58532A GPS Antenna : Launch3 Surplus

Hi There are tapes designed for waterproofing things like coax connectors. Bob > On Feb 9, 2018, at 7:41 PM, Hal Murray wrote: > > > li...@philpem.me.uk said: >> Generally speaking, you can seal most RF connectors quite nicely with a few >> layers of

Re: [time-nuts] eBay GPS antenna test results.

Hi Is it labeled 3.3 to 18V on the antenna? Bob > On Feb 9, 2018, at 4:43 PM, John Green wrote: > > To those who doubted that the antenna was actually a 3.3 to 18 volt design, > it seems you were correct. Today, I hooked it up to a variable power supply > and slowly raised

Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

Hi It depends a *lot* on the frequency counter. An old style “just count the number of edges” device should be good to go pretty fast. One of the “fry an egg on it” interpolating counters that get into the 20 ps range may well need some time to stabilize. If you are doing ADEV runs, a couple

Re: [time-nuts] Anyone have experience with this antenna?

not a big deal in most cases. Bob > On Feb 7, 2018, at 10:07 AM, Poul-Henning Kamp <p...@phk.freebsd.dk> wrote: > > > In message <875e4bc6-32c3-4724-afcd-086553ae5...@n1k.org>, Bob kb8tq writes: > >> Water wise, one might note the large pil

Re: [time-nuts] Anyone have experience with this antenna?

Hi It’s not the end stops that are the issue. It’s the wall of the pipe. If the dimensions in the sketch are roughly correct and you scale it to the dimensions of the eBay antenna, that is a big tall pipe. Indeed “nothing overhead” would mitigate part of the issue. That magic line runs

Re: [time-nuts] Receiving the MSF time signal on cheap radio modules

Hi Back in the era of VLF disciplined oscillators, carrier phase was the preferred approach. Getting that to work with 100% AM modulation took some effort …. Bob > On Feb 7, 2018, at 2:13 AM, Poul-Henning Kamp wrote: > > > In message >

Re: [time-nuts] eBay GPS antenna.

Hi If you spend some “quality time” with the pictures in the listing, the antenna is indeed labeled “operating voltage 3.3 to 18V”. Yes, I find that a bit incredible. If there is nonsense being generated, it’s not by the person listing the antenna on eBay. My guess would be that the

Re: [time-nuts] Receiving the MSF time signal on cheap radio modules

Hi > On Feb 6, 2018, at 3:48 PM, Deirdre O'Byrne wrote: > > Tom, > > Thanks for the feedback! > > On 6 February 2018 at 20:29, Tom Van Baak wrote: > >> >> 2) Not all decoding errors are equal. Since this is a time code instead of >> arbitrary

Re: [time-nuts] Receiving the MSF time signal on cheap radio modules

Hi If you look at the papers for the “new” WWVB format, there are plots of where the MSF issues are likely to be the greatest. Since both signals are phase and amplitude shifted by propagation effects, you will not get stationary nulls. You simply get zones where the reception is tough. Bob

Re: [time-nuts] Receiving the MSF time signal on cheap radio modules

Hi > On Feb 6, 2018, at 4:19 PM, Poul-Henning Kamp wrote: > > > In message > , > "Deirdre O'Byrne" writes: > >> With a blame algorithm in place it should be possible to recover these >>

Re: [time-nuts] Anyone have experience with this antenna?

on available from > post-processed, carrier phase time-transfer but invisible in the 1 pps > coming out of your receiver, even with a good sawtooth correction. Am I > missing something? > > Cheers > Michael > > On Wed, 7 Feb 2018 at 4:14 am, Bob kb8tq <kb...@n1k.org>

Re: [time-nuts] Receiving the MSF time signal on cheap radio modules

Hi If you want to get even more “nutty", look at the “seed” that you likely already have for the computation. In this day and age, you probably know what day / month / year it is. Since you might not (say) know the hour, you have a +/- 1 day sort of tolerance on that. It rolls into month

Re: [time-nuts] Symmetricom 58532A GPS Antenna : Launch3 Surplus

Hi That’s likely a “better” antenna for a TBolt-only setup than the L1 / L2 gizmo that we have been chatting about. Why? 1) if it’s still $25 it would be ~ 1/4 the price 2) it has a pretty good filter built into it. 3) it’s designed for continuous outdoor use (connector is well shielded

Re: [time-nuts] Anyone have experience with this antenna?

Hi The microwave trick is fine for working out if it is a lossy material. Unfortunately what gets you in this case is more than just loss. A coax cable has core material that will (usually) do quite well in a microwave. None the less, the delay through the coax is different than through air

Re: [time-nuts] Anyone have experience with this antenna?

Hi There are “cell site” specific GPS antennas on the market. Panasonic has had one out for quite a while. I’m sure there are several others. One issue with doing any sort of “cover” for a precision antenna is distorting it’s pattern. Plastic (or whatever you use) will have different

Re: [time-nuts] eBay GPS antenna.

Hi There is no need for something this exotic for L1 only reception. It *is* nice to have Glonass L1, but that’s about the extent of how fancy you need to go. As noted in another post, the preamp gain probably is pretty high on this antenna. That’s a standard that goes back to the early days

Re: [time-nuts] Anyone have experience with this antenna?

Hi One gotcha (if the data sheets are correct) is going to be the supply voltage. We normally stay away from 12V antennas because TBolt’s put out 5V. In the case of a survey antenna, 12V is what most of the gear puts out. I don’t know of any L1 / L2 gear that puts out 5 rather than 12V …. Bob >

Re: [time-nuts] Etching of quartz crystals

Hi > On Feb 5, 2018, at 10:31 AM, jimlux <jim...@earthlink.net> wrote: > > On 2/5/18 5:54 AM, Attila Kinali wrote: >> On Sun, 4 Feb 2018 09:21:54 -0500 >> Bob kb8tq <kb...@n1k.org> wrote: >>>> The images on this page gives a good impression ab

Re: [time-nuts] Etching of quartz crystals (was: Rakon HSO-14)

Hi > On Feb 5, 2018, at 8:54 AM, Attila Kinali <att...@kinali.ch> wrote: > > On Sun, 4 Feb 2018 09:21:54 -0500 > Bob kb8tq <kb...@n1k.org> wrote: > >>> The images on this page gives a good impression about the current >>> skill-level in th

Re: [time-nuts] Rakon HSO-14

Hi Obviously you need two more 8607’s ….. :) I suspect you are correct and the OCXO is doing better than the close in data suggests. Bob > On Feb 4, 2018, at 8:33 AM, Tom Van Baak wrote: > > FYI: here's an old plot where I evaluated an Oscilloquartz 8607 BVA against a

Re: [time-nuts] Rakon HSO-14

Hi > On Feb 4, 2018, at 7:13 AM, Poul-Henning Kamp wrote: > > > In message <480971424.644410.1517715556...@webmail.xtra.co.nz>, Bruce > Griffiths > writes: > >> It has been used to machine/polish crystal quartz waveplates and >> to machine/polish the surface of

Re: [time-nuts] Rakon HSO-14

Hi Anything like a laser that generates heat to do the “work” will twin the quartz. Once you do that, it’s pretty much useless as a resonator. The same issue gets you in trouble trying to wire bond to a resonator. Bob > On Feb 3, 2018, at 9:46 PM, Hal Murray wrote:

Re: [time-nuts] Rakon HSO-14

quartz and optical glass there is no associated subsurface > damage. > > Bruce > > On 04 February 2018 at 14:05 Bob kb8tq <kb...@n1k.org> wrote: > > Hi > > If you try “normal” machining techniques on a resonator, you are very > likely to create micro cracks in the materia

Re: [time-nuts] Rakon HSO-14

Hi If you try “normal” machining techniques on a resonator, you are very likely to create micro cracks in the material. Those are *really* bad for aging and a few other issues ….. Much of the normal production flow of the quartz is designed to keep the processes like sawing far enough away from

<    1   2   3   4   5   6   7   8   9   >