Re: [time-nuts] What is the best way to multiply a 10 Mhz
On 22/12/10 15:55, Richard (Rick) Karlquist wrote: On 12/21/2010 10:11 PM, Bernd Neubig wrote: Hi Rick, I have a problem to imagine how you connect the LO and RF port of a mixer in series and drive it (the IF port?) with a ... sine wave. Can you send me a sketch of this arrangement please? Tnx a lot! Best regards Bernd Neubig DK1AG Good question. I am posting this in case others were confused. On the ASK-1, pins 2, 3 and 6 are NOT internally connected. This is confusing because the data sheet denotes them all as "Ground". I forgot to mention this because it is intuitive to me. There is a statement to this effect somewhere in an ap note. There are many mixers which the datasheet makes you beleive that the "ground" pins is internally connected while they in fact are not. In fact, the way they are actually built it would complicate things with no apparent gain. Using the ports floating is much more useful. The netlist is as follows: 10 MHz to pin 1 of inductor Pin 2 of inductor to pin 1 of capacitor Pin 2 of capacitor to pin 1 of ASK-1 Pin 3 of ASK-1 to Pin 4 of ASK-1 Pins 6 of ASK-1 to ground The X2 output comes from pins 4 and 5 (the "IF"). Usually you would connect pin 5 to the same ground as pin 6, but you could also take the output differentially (IE floating). The capacitor and inductor resonate at 10 MHz, the loaded Q is around 4. The drive impedance of the ASK-1 as indicated is around 30 ohms IIRC. Of course, many other mixer models can be used, as long as they have both sides of the LO port available. Thanks. 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.
Re: [time-nuts] counter
> -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]On > Behalf Of Don Latham > Sent: Saturday, January 29, 2011 11:13 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] counter > > > Aha. good to know. Do you suppose if we put on our thinking caps we can > get the academic pricing? Would whinging or outright begging do it? > :-) > Not that the decks are cleared for this project yet. Heck, my picII's > aren't built or programmed. > > Don > Can't hurt to ask! It's also possible that KNJN's policies are very different now. I'm not necessarily trying to steer anyone away from using them, so much as trying to keep people from wasting as much time as I did. The fact that he's still in business at all tells me that the requirement to run the configuration .exe is probably no longer in effect. -- john, KE5FX ___ 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] counter
Aha. good to know. Do you suppose if we put on our thinking caps we can get the academic pricing? Would whinging or outright begging do it? :-) Not that the decks are cleared for this project yet. Heck, my picII's aren't built or programmed. Don John Miles > >> >> With regard to the home-brew counter project, if it still exists: >> >> >From friend Marcus Leech on another list: >> >> "Don't know whether you've seen these: >> >> http://www.knjn.com/ShopBoards_USB2.html >> >> $79.95 for the low-end board, which includes and FX2, and a small >> Cyclone FPGA. Pretty good >> value." >> >> Thanks, Marcus. this looks like the very thing, just need the "front >> end" >> >> Don >> >> > > One word of warning, purely hypothetical in nature. As of a couple of > years > ago, rumor had it that the guy who runs knjn.com (also fpga4fun.com) was > convinced that his customers wouldn't mind running his proprietary .exe to > configure the board's USB chip and FPGA every time the device boots up. > Schematics were supposedly also not available at that time. If these > rumored policies still prevail, that means you'll have to reverse-engineer > the board's JTAG-over-USB connections in order to do anything practical > with > it. Oh, and also, if you propose open-sourcing the results of your > reverse > engineering effort, he may or may not throw a fit and accuse you of > setting > out to wreck his business model. > > Not that I have any direct knowledge along these lines. :-P > > Suggest going with a Digilent board instead -- the Nexys 2 is a bit more > expensive but infinitely more 'hacker friendly' than any of the KNJN > products. At the very least, you want to contact knjn.com before > committing > to their board and ask some very pointed questions about the development > process and support code. > > -- john, KE5FX > > > ___ > 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. > -- "Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind." R. Bacon "If you don't know what it is, don't poke it." Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 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.
Re: [time-nuts] counter
> > With regard to the home-brew counter project, if it still exists: > > >From friend Marcus Leech on another list: > > "Don't know whether you've seen these: > > http://www.knjn.com/ShopBoards_USB2.html > > $79.95 for the low-end board, which includes and FX2, and a small > Cyclone FPGA. Pretty good > value." > > Thanks, Marcus. this looks like the very thing, just need the "front end" > > Don > > One word of warning, purely hypothetical in nature. As of a couple of years ago, rumor had it that the guy who runs knjn.com (also fpga4fun.com) was convinced that his customers wouldn't mind running his proprietary .exe to configure the board's USB chip and FPGA every time the device boots up. Schematics were supposedly also not available at that time. If these rumored policies still prevail, that means you'll have to reverse-engineer the board's JTAG-over-USB connections in order to do anything practical with it. Oh, and also, if you propose open-sourcing the results of your reverse engineering effort, he may or may not throw a fit and accuse you of setting out to wreck his business model. Not that I have any direct knowledge along these lines. :-P Suggest going with a Digilent board instead -- the Nexys 2 is a bit more expensive but infinitely more 'hacker friendly' than any of the KNJN products. At the very least, you want to contact knjn.com before committing to their board and ask some very pointed questions about the development process and support code. -- john, KE5FX ___ 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] counter
With regard to the home-brew counter project, if it still exists: >From friend Marcus Leech on another list: "Don't know whether you've seen these: http://www.knjn.com/ShopBoards_USB2.html $79.95 for the low-end board, which includes and FX2, and a small Cyclone FPGA. Pretty good value." Thanks, Marcus. this looks like the very thing, just need the "front end" Don -- "Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind." R. Bacon "If you don't know what it is, don't poke it." Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 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.
Re: [time-nuts] Temperature stability for Thunderbolt: results
I solved the same problem today by putting the antenna in the skylight dome in my 'office'. Between the heat loss and the dome shape the snow pretty much stays off of the skylight. This is after I just had the antenna laying on the roof, where it got buried under 10+inches of snow in the last week or two. On Sat, Jan 29, 2011 at 12:14 PM, Charles P. Steinmetz wrote: > Magnus wrote: > >> Maybe a LH controlled hair-dryer to burn off some snow? > > I have actually given some thought to adding a de-icer (heater) to my > outdoor antenna, as is done with many broadcast, radar, etc. antennas. Of > course, it wouldn't need to be controlled by LH -- a manual switch indoors > and a thermostat near or attached to the antenna would be sufficient. > > My present solution is to fall back on an indoor antenna. Placed in the > attic, looking through just the roof (not the indoor ceiling, as well), the > results are nearly as good as the outdoor antenna (I lose about 2 dB net > through the roof plus 10" of snow, compared to the outdoor antenna -- the > actual field loss is presumably somewhat greater, but is partially offset by > the additional 75 feet (~25 m) of coax on the outdoor antenna). > > Best regards, > > Charles > > > ___ > 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 stability for Thunderbolt: results
Magnus wrote: Maybe a LH controlled hair-dryer to burn off some snow? I have actually given some thought to adding a de-icer (heater) to my outdoor antenna, as is done with many broadcast, radar, etc. antennas. Of course, it wouldn't need to be controlled by LH -- a manual switch indoors and a thermostat near or attached to the antenna would be sufficient. My present solution is to fall back on an indoor antenna. Placed in the attic, looking through just the roof (not the indoor ceiling, as well), the results are nearly as good as the outdoor antenna (I lose about 2 dB net through the roof plus 10" of snow, compared to the outdoor antenna -- the actual field loss is presumably somewhat greater, but is partially offset by the additional 75 feet (~25 m) of coax on the outdoor antenna). Best regards, Charles ___ 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] worth salvaging ?
On Jan 29, 2011, at 4:03 PM, David Martindale wrote: > It all depends on the receiver firmware. [...] > In a little while, Garmin released a small utility that you > ran on a PC connected to the GPS via its serial port, and it reset > something that allowed the GPS to do a successful cold start. I > remember an rumour that it simply reset the saved date and time far > enough away that the receiver dumped all its old almanac entries, > forcing it to do a cold start that worked. Ah, yes. If the receiver is too stubborn to give up and do a very cold start, then it may single-mindedly continue searching exactly where the satellites aren't! -- Mark J. Blair, NF6X Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] worth salvaging ?
> You want to scrap these because??? time to thin the 'stuff' herd, i.e. I need the room. There at one time were over 100 of these things, and maybe 40 recovered antenna/downconverters. Add each has a 50' or 100' coax cable, a power supply and they are taking a lot of space. Just about every antenna/downconverter that lived outside is dead. Plus I've been offered more for the HP displays then I've been for the units. For those curious they came from a company I worked at that is long dead. They where only interested in a decent 1 PPS and to replace Spectracom WWVB clocks. Odetics won the bid for 1,000 units and within a few months of being installed the started to die. 90% where located in FM radio transmitter buildings, so of which would cost $1,000 via helicopter to get to in the winter. When they where replaced many of the Antenna/downcoverters were just left behind. Odetics picked up the bill to have them all replaced. They were suppose to be destroyed but being a pack rat, I pulled them all out of the dropbox. anyway .. I'll part out a few, take the HP LED's and offer them to the t'nuts list members for the cost of shipping. I'll find out how much can be shoved in a USPS flat rate box next week. -pete ___ 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] FRS-C Rb Oscillator questions
Hi guys, Today I received a shiny new (to me anyway) FRS-C Rb from one of the usual sellers in China. It locked after roughly 2 minutes. Comparing it to my Thunderbolt I saw that it was running at a very slightly different rate. I adjusted the c-field pot and made it slightly better but I ran out of range on the pot! It's fully counter-clockwise and one trace is moving past the other very slowly. I can speed it up by turning it all the way to the right but it never stops or changes direction. Is there anything I can do that isn't too difficult to remedy the situation? Should I let it warm up overnight before messing with this? (my other unit does not have this problem -at least it didn't before I killed it). Thank you for any suggestions, Bob (ps, the thunderbolt has been on for over a year so I don't think that's the issue but I really don't have any way to verify it. Lady Heather thinks it's okay. ___ 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] worth salvaging ?
Peter was looking at the down converter pixs. Several comments they are in quite good shape at least these pixs. The resolution on 2740 and 42 are just at the edge so when you expand everything you loose the part numbers so if they could be read the frequency scheme might be reversed out. I am indeed wondering if the pll arrangement is the same as the austron. 10 Mhz ref up coax First mixer is 1500 Mhz and downconverts to 75.42 MHz first IF down coax. You want to scrap these because??? Thanks Paul. On Sat, Jan 29, 2011 at 7:03 PM, David Martindale wrote: > On Sat, Jan 29, 2011 at 10:14 AM, Mark J. Blair wrote: > > > In a receiver that doesn't have a recent almanac, and particularly in an > older receiver that takes a very simple approach to downloading ephemeris > and almanac information, initial acquisition could take a long time. It'll > need to do a slow full-sky search for its first satellite, and older > receivers couldn't do that nearly as quickly as newer ones can. Once it gets > that first bird, it may sit there downloading ephemeris and almanac data for > at least 12.5 minutes before it does anything else. With an old receiver > from that era, give it at least a half hour of good open-sky conditions > before you begin to suspect that it's dead. > > It all depends on the receiver firmware. I remember when the GPS week > rolled over; I was in the process of driving from a conference in > California back to home in British Columbia, with a GPS receiver or > two in the car tracking our progress. We stopped for a meal, powering > the GPS receivers off. When we returned to the car, one of the > receivers (a Garmin) would not re-acquire satellites no matter how > long I gave it. I later figured out that the week rollover had > happened that afternoon, while we were driving, and the first restart > after the rollover failed. > > But it apparently wasn't just a case of having to do a cold start to > get a new almanac, because I couldn't get that receiver to work again > myself. In a little while, Garmin released a small utility that you > ran on a PC connected to the GPS via its serial port, and it reset > something that allowed the GPS to do a successful cold start. I > remember an rumour that it simply reset the saved date and time far > enough away that the receiver dumped all its old almanac entries, > forcing it to do a cold start that worked. This suggests that it had > been keeping its pre-rollover almanac data and tried to use it, but > there was a bug in the calculation that resulted in mispredicting what > satellites should be visible where. But that's just a guess - Garmin > never said exactly what was wrong, or what they did to fix it. > > > Back to the original topic now: That OCXO may seem mundane by time-nutty > standards, but I'd certainly consider it to be worth salvaging. It could > have all sorts of applications for radio stuff, portable test equipment, and > even time-nutty stuff in an application that wants to be smaller and more > portable than a Rb standard or full GPSDO. > > Yes. If you offered them for postage cost, you'd probably find a > bunch of takers. You wouldn't even have to unsolder them - let the > recipient do that. It seems a waste to discard a perfectly good OCXO > - it would make a fine upgrade to an inexpensive frequency counter > (many of which just have a bare crystal, not even a TCXO). > > ___ > 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] worth salvaging ?
On Sat, Jan 29, 2011 at 10:14 AM, Mark J. Blair wrote: > In a receiver that doesn't have a recent almanac, and particularly in an > older receiver that takes a very simple approach to downloading ephemeris and > almanac information, initial acquisition could take a long time. It'll need > to do a slow full-sky search for its first satellite, and older receivers > couldn't do that nearly as quickly as newer ones can. Once it gets that first > bird, it may sit there downloading ephemeris and almanac data for at least > 12.5 minutes before it does anything else. With an old receiver from that > era, give it at least a half hour of good open-sky conditions before you > begin to suspect that it's dead. It all depends on the receiver firmware. I remember when the GPS week rolled over; I was in the process of driving from a conference in California back to home in British Columbia, with a GPS receiver or two in the car tracking our progress. We stopped for a meal, powering the GPS receivers off. When we returned to the car, one of the receivers (a Garmin) would not re-acquire satellites no matter how long I gave it. I later figured out that the week rollover had happened that afternoon, while we were driving, and the first restart after the rollover failed. But it apparently wasn't just a case of having to do a cold start to get a new almanac, because I couldn't get that receiver to work again myself. In a little while, Garmin released a small utility that you ran on a PC connected to the GPS via its serial port, and it reset something that allowed the GPS to do a successful cold start. I remember an rumour that it simply reset the saved date and time far enough away that the receiver dumped all its old almanac entries, forcing it to do a cold start that worked. This suggests that it had been keeping its pre-rollover almanac data and tried to use it, but there was a bug in the calculation that resulted in mispredicting what satellites should be visible where. But that's just a guess - Garmin never said exactly what was wrong, or what they did to fix it. > Back to the original topic now: That OCXO may seem mundane by time-nutty > standards, but I'd certainly consider it to be worth salvaging. It could have > all sorts of applications for radio stuff, portable test equipment, and even > time-nutty stuff in an application that wants to be smaller and more portable > than a Rb standard or full GPSDO. Yes. If you offered them for postage cost, you'd probably find a bunch of takers. You wouldn't even have to unsolder them - let the recipient do that. It seems a waste to discard a perfectly good OCXO - it would make a fine upgrade to an inexpensive frequency counter (many of which just have a bare crystal, not even a TCXO). ___ 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] Clock Calibration
I have a little piezo sounder on the PPS from a t/bolt. It runs off a cmos gate, I can not remember whether I put some pulse stretching in, but it needs an on/off switch or the ticking will drive you mad. This is great to use with the UTC time on LH. You look at the time, then keep counting with the audible ticks to guide you while you check your analogue clocks. I also have a BCD counter dividing the 10MHz from the T/Bolt that drives a time display. As well, the milliseconds, 100 microseconds, or 10s of microseconds are counted and can be latched by a proximity switch into a homebrew BCD DAC which is recorded by a HOBO logger to give very accurate logging of phase for whichever clock the proximity is clipped to. It is all low power, saves serious frequency counters, PC et. al. so you can log continuously for years without a major power bill. cheers, Neville Michie On 30/01/2011, at 4:16 AM, scmcgr...@gmail.com wrote: Ah now from time nuttery to horology. There are those of us who tinker with analog clocks as well... Generally we 'beat' clocks against 'standard' clocks or more recently a pc application with a microphone over long periods of time generally at least a week and commonly a month. Scott Sent from my Verizon Wireless BlackBerry -Original Message- From: Chris Albertson Sender: time-nuts-boun...@febo.com Date: Thu, 27 Jan 2011 15:52:49 To: Discussion of precise time and frequency measurementn...@febo.com> Reply-To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Clock Calibration On Thu, Jan 27, 2011 at 12:55 PM, Perry Sandeen wrote: ...how the heck they were able to calibrate a clock to milliseconds per day back then? Let it run for 1,000 days, then you only need to be able to measure to the nearest second to get to ms per day. Or maybe you can measure to 0.1 seconds so it only takes 100 days. The trouble is that using this method you don't know the average error. A good example is an eccentric gear that makes a second hand run fast then slow but if averaged over a long period is near perfect. I doubt they were able to catch stuff like that. -- = Chris Albertson Redondo Beach, California ___ 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] worth salvaging ?
I'll keep one or two here's some pictures of the inside of the down converter http://petelancashire.com/gallery/main.php?g2_itemId=19822&g2_page=2 for detail, click on the thumbnail, the for full resolution click on the picture or select the resolution near the upper right On Sat, Jan 29, 2011 at 1:03 PM, paul swed wrote: > On the 2201 I do give it quite a while to get its act together hours. To an > extent it seems to. > But the fact that the sat tables which you can view never seem to come into > alignment with whats going on for real is why I think it may be a lost > cause. > > Back to odetics, > So it seems at least one works. Peter wouldn't you just keep it around or is > it sloppy compared to todays Tbolts and such? > Seems a shame to part'em out if they work unless they really aren't that > useful. > > On Sat, Jan 29, 2011 at 1:14 PM, Mark J. Blair wrote: > >> >> On Jan 29, 2011, at 6:43 AM, paul swed wrote: >> > It seems to interpret the almanacs wrong because amazingly enough its >> > actually does know the correct GPS week which was a shock to me. Unless >> > thats a simple calculation from the date I might guess. >> >> It's the other way around: The GPS week is directly decoded from the GPS >> signal. If I'm not mistaken, the GPS week roll-over causes a problem of >> being able to correctly calculate the calendar date from the GPS week. I >> could be mistaken, but I think that a receiver that doesn't handle the >> rollover properly but is otherwise in good shape should be able to track >> satellites and provide a correct position, but the calendar/clock time >> calculation would be wrong. >> >> In a receiver that doesn't have a recent almanac, and particularly in an >> older receiver that takes a very simple approach to downloading ephemeris >> and almanac information, initial acquisition could take a long time. It'll >> need to do a slow full-sky search for its first satellite, and older >> receivers couldn't do that nearly as quickly as newer ones can. Once it gets >> that first bird, it may sit there downloading ephemeris and almanac data for >> at least 12.5 minutes before it does anything else. With an old receiver >> from that era, give it at least a half hour of good open-sky conditions >> before you begin to suspect that it's dead. >> >> >> Back to the original topic now: That OCXO may seem mundane by time-nutty >> standards, but I'd certainly consider it to be worth salvaging. It could >> have all sorts of applications for radio stuff, portable test equipment, and >> even time-nutty stuff in an application that wants to be smaller and more >> portable than a Rb standard or full GPSDO. >> >> I also agree that there's likely to be a lot more salvageable stuff on >> those boards. I see lots of socketed parts. UV-erasable EPROMs are worth >> saving. Are those Altera parts reprogrammable? If so, then they're worth >> keeping. Keep any microcontrollers or CPUs that are reprogrammable, or rely >> on external program memory, or can still be used in spite of fixed internal >> programming (e.g., an old mask-programmed 8051 can be used as an 8031 by >> strapping a pin to tell it to ignore its mask ROM and use external program >> memory). >> >> I'd say that any units which track satellites at all after a half hour >> should be considered for repair, and the rest of the units are goldmines of >> parts. >> >> >> >> -- >> Mark J. Blair, NF6X >> Web page: http://www.nf6x.net/ >> GnuPG public key available from my web page. >> >> >> >> >> >> ___ >> 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] worth salvaging ?
On the 2201 I do give it quite a while to get its act together hours. To an extent it seems to. But the fact that the sat tables which you can view never seem to come into alignment with whats going on for real is why I think it may be a lost cause. Back to odetics, So it seems at least one works. Peter wouldn't you just keep it around or is it sloppy compared to todays Tbolts and such? Seems a shame to part'em out if they work unless they really aren't that useful. On Sat, Jan 29, 2011 at 1:14 PM, Mark J. Blair wrote: > > On Jan 29, 2011, at 6:43 AM, paul swed wrote: > > It seems to interpret the almanacs wrong because amazingly enough its > > actually does know the correct GPS week which was a shock to me. Unless > > thats a simple calculation from the date I might guess. > > It's the other way around: The GPS week is directly decoded from the GPS > signal. If I'm not mistaken, the GPS week roll-over causes a problem of > being able to correctly calculate the calendar date from the GPS week. I > could be mistaken, but I think that a receiver that doesn't handle the > rollover properly but is otherwise in good shape should be able to track > satellites and provide a correct position, but the calendar/clock time > calculation would be wrong. > > In a receiver that doesn't have a recent almanac, and particularly in an > older receiver that takes a very simple approach to downloading ephemeris > and almanac information, initial acquisition could take a long time. It'll > need to do a slow full-sky search for its first satellite, and older > receivers couldn't do that nearly as quickly as newer ones can. Once it gets > that first bird, it may sit there downloading ephemeris and almanac data for > at least 12.5 minutes before it does anything else. With an old receiver > from that era, give it at least a half hour of good open-sky conditions > before you begin to suspect that it's dead. > > > Back to the original topic now: That OCXO may seem mundane by time-nutty > standards, but I'd certainly consider it to be worth salvaging. It could > have all sorts of applications for radio stuff, portable test equipment, and > even time-nutty stuff in an application that wants to be smaller and more > portable than a Rb standard or full GPSDO. > > I also agree that there's likely to be a lot more salvageable stuff on > those boards. I see lots of socketed parts. UV-erasable EPROMs are worth > saving. Are those Altera parts reprogrammable? If so, then they're worth > keeping. Keep any microcontrollers or CPUs that are reprogrammable, or rely > on external program memory, or can still be used in spite of fixed internal > programming (e.g., an old mask-programmed 8051 can be used as an 8031 by > strapping a pin to tell it to ignore its mask ROM and use external program > memory). > > I'd say that any units which track satellites at all after a half hour > should be considered for repair, and the rest of the units are goldmines of > parts. > > > > -- > Mark J. Blair, NF6X > Web page: http://www.nf6x.net/ > GnuPG public key available from my web page. > > > > > > ___ > 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] spur prediction DDS software
I don't know how good it has to be but have you considered the Si570 or even one of the bigger more power hungry candidates from silabs? Really easy to drive this chip! - Henry Luis Cupido schrieb: Jim, Bob, Henry, Brian, Thanks to all. Very good. yeap, I do work on matlab so I think there is plenty now to keep me busy ;-) tks. Luis Cupido ct1dmk. p.s.(what's cooking) I need a relatively narrow tunning range but absolutely free of close in spurs, willing to see if a modest size DDS (inside an FPGA) will do so... and what parameters will be... ___ 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 standards for characterizing GPSDO's ?
On 29/01/11 20:53, Mark Spencer wrote: Greetings I'm looking suggestions for a frequency standard for characterizing GPSDO's. I've got one 10811 (out of 3) that seems to be stable enough to be able to use as a frequency reference to draw conclusions about GPSDO performance using a 5370B counter in time interval mode. (It typically takes several thousand seconds for a phase wrap to occur.) I'm contemplating acquiring a Rubidium standard as a next step and would be interested in any opinions as logical next steps. Consider a PICTIC II and a FEI rubidium (or compatible from Temex). Toss a processor of choice to take the PICTIC II data, implement a PI-regulator and then steer the rubidium over the serial interface. For best system design one would need four serial interfaces (GPS, rubidium, PICTIC II and supervision). Would be a rather neat solution. 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.
Re: [time-nuts] power spectrum of hard limiter output
Hi Magnus - Well. I made homework for sure. Endless viewed websites what others had done. We all seek for the singularity of beauty in our art. At the moment this is a CD4007 or similar without AGC. Cheap, effective. Not oversized. I came from TCA440. One of the not many receiver chips where the IF is at one output reachable. Then I found I must increase carrier frequency beyound 30MHz. So the integrated mixer entered useless. I used an external device. Next I found that the integrated IF-strip is not one of the quiets... Remembering several statements about using CMOS inverters in s.e.d. for analog reasons, the way was clear... Implementing an AGC makes the design much more complicated. Can oscillate etc. Going without AGC seems a reasonable way if the modulation is one of the phase modulation systems where amplitude is not very important. Then look how big is the dynamic range of a simple CMOS inverter. Meanwhile I found two examples made by others. So the way looks not to idiotic ;-) - Henry Magnus Danielson schrieb: I find it more and more curious a working concept not to find in the I-net. I'm looking several weeks. Maybe wrong keywords. Well, have you considered what an AGC might do for you? It has been the traditional way of reducing the effect of signal level on phase-detector gain and hence on the loop gain. The hard-limiter text is to be seen in this context where the SNR steers the compression factor, i.e. change of loop gain. 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] Frequency standards for characterizing GPSDO's ?
Greetings I'm looking suggestions for a frequency standard for characterizing GPSDO's. I've got one 10811 (out of 3) that seems to be stable enough to be able to use as a frequency reference to draw conclusions about GPSDO performance using a 5370B counter in time interval mode. (It typically takes several thousand seconds for a phase wrap to occur.) I'm contemplating acquiring a Rubidium standard as a next step and would be interested in any opinions as logical next steps. That being said I don't see my self acquiring a cesium standard or hydrogen maser any time soon (: Best regards Mark Spencer ___ 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] worth salvaging ?
On Jan 29, 2011, at 6:43 AM, paul swed wrote: > It seems to interpret the almanacs wrong because amazingly enough its > actually does know the correct GPS week which was a shock to me. Unless > thats a simple calculation from the date I might guess. It's the other way around: The GPS week is directly decoded from the GPS signal. If I'm not mistaken, the GPS week roll-over causes a problem of being able to correctly calculate the calendar date from the GPS week. I could be mistaken, but I think that a receiver that doesn't handle the rollover properly but is otherwise in good shape should be able to track satellites and provide a correct position, but the calendar/clock time calculation would be wrong. In a receiver that doesn't have a recent almanac, and particularly in an older receiver that takes a very simple approach to downloading ephemeris and almanac information, initial acquisition could take a long time. It'll need to do a slow full-sky search for its first satellite, and older receivers couldn't do that nearly as quickly as newer ones can. Once it gets that first bird, it may sit there downloading ephemeris and almanac data for at least 12.5 minutes before it does anything else. With an old receiver from that era, give it at least a half hour of good open-sky conditions before you begin to suspect that it's dead. Back to the original topic now: That OCXO may seem mundane by time-nutty standards, but I'd certainly consider it to be worth salvaging. It could have all sorts of applications for radio stuff, portable test equipment, and even time-nutty stuff in an application that wants to be smaller and more portable than a Rb standard or full GPSDO. I also agree that there's likely to be a lot more salvageable stuff on those boards. I see lots of socketed parts. UV-erasable EPROMs are worth saving. Are those Altera parts reprogrammable? If so, then they're worth keeping. Keep any microcontrollers or CPUs that are reprogrammable, or rely on external program memory, or can still be used in spite of fixed internal programming (e.g., an old mask-programmed 8051 can be used as an 8031 by strapping a pin to tell it to ignore its mask ROM and use external program memory). I'd say that any units which track satellites at all after a half hour should be considered for repair, and the rest of the units are goldmines of parts. -- Mark J. Blair, NF6X Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Clock Calibration
Ah now from time nuttery to horology. There are those of us who tinker with analog clocks as well... Generally we 'beat' clocks against 'standard' clocks or more recently a pc application with a microphone over long periods of time generally at least a week and commonly a month. Scott Sent from my Verizon Wireless BlackBerry -Original Message- From: Chris Albertson Sender: time-nuts-boun...@febo.com Date: Thu, 27 Jan 2011 15:52:49 To: Discussion of precise time and frequency measurement Reply-To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Clock Calibration On Thu, Jan 27, 2011 at 12:55 PM, Perry Sandeen wrote: > ...how the heck they were able to calibrate a clock to milliseconds per day > back then? Let it run for 1,000 days, then you only need to be able to measure to the nearest second to get to ms per day. Or maybe you can measure to 0.1 seconds so it only takes 100 days. The trouble is that using this method you don't know the average error. A good example is an eccentric gear that makes a second hand run fast then slow but if averaged over a long period is near perfect. I doubt they were able to catch stuff like that. -- = Chris Albertson Redondo Beach, California ___ 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 stability for Thunderbolt: results
On 29/01/11 16:40, WarrenS wrote: Yea, I know, Me too :-) Great. :) And there probable is something in LH that will do that, If not now then soon with the next beta3 update. Hmm. LH seems to be more and more of a swiss army-knife... ah well. Two other solutions for the snow. Move your Antenna AND Tbolt to California where there is NO snow, OR That will be one hell of a long run of PPS, 10 MHz and RS-232. Move your Antenna indoors where hopefully there is no snow. The antennas I have indoor so far has no major accumulation of snow, where as the outdoor antennas do have that problem. When enough of it has melted away I may get up and see if I can't get some better reception. My indoor antenna works fine for most applications and keeps the freq within a few parts in e-11. For indoors, It helps to increase the TC by about x2 and set the Elevation up and AMU down some to help it handle the added GPS noise it'll see. I have been wondering if adjustment of position could lower the time-shifts as sats is included or not. But it doesn't help for combating the biasing factors of multipath. 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.
Re: [time-nuts] worth salvaging ?
On 28/01/11 00:54, Pete Lancashire wrote: I'm getting ready to scrap a bunch of the Odetics GPStar's I have for the cool 5x7 HP LED displays Those are always nice to have. :) Of the 11 antenna/down converters I've found one works. http://petelancashire.com/gallery/main.php?g2_itemId=19820 I'd like the lists opinion if saving the OCXO is worth puling of the board http://www.microcrystal.com/CMSPages/GetFile.aspx?nodeguid=6f5af9ba-b6a1-4bae-bab7-5e4e95a5c796 Not too bad. It's not a big OCXO but worth keeping. 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.
Re: [time-nuts] Temperature stability for Thunderbolt: results
Yea, I know, Me too :-) And there probable is something in LH that will do that, If not now then soon with the next beta3 update. Two other solutions for the snow. Move your Antenna AND Tbolt to California where there is NO snow, OR Move your Antenna indoors where hopefully there is no snow. My indoor antenna works fine for most applications and keeps the freq within a few parts in e-11. For indoors, It helps to increase the TC by about x2 and set the Elevation up and AMU down some to help it handle the added GPS noise it'll see. ws ** On 29/01/11 13:46, WarrenS wrote: >> >> Check with Mark, It is probable in there some where as an undocumented >> feature, I know the 'MOON MAN' thing is in there. >> I tried LH's temperature controller as a room thermostat once by >> connecting it up to a infrared electric heater thru an isolated SCR switch. >> >> I figured, why just keep the Tbolt constant when you can keep the whole >> room constant. >> Because it will control a Heater and/or a Fan the hair-dryer thing >> should work also. >I was discussing hair-dryer mounted on the antenna mast, somewhat >jokeingly naturally. The Tbolt would be sitting warm and snow-free >inside the house I guess. > >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.
Re: [time-nuts] worth salvaging ?
Hal Thanks for your comments. Not sure I want to depart from Peters thread to far. I was aware of several items y2K, the GPS rollover and I seem to recall a 3rd thing. It seems to interpret the almanacs wrong because amazingly enough its actually does know the correct GPS week which was a shock to me. Unless thats a simple calculation from the date I might guess. But additionally it tends to track for a while and at times a long while at least 1 sat. But never seems to go to 2-3. Running a garmin so that I can see the real satellites shows that what the austron wants to track may or may not be real kind of pot luck. Email me, or start a separate thread and we can give this back to Peter. Regards Paul WB8TSL On Fri, Jan 28, 2011 at 11:03 PM, Hal Murray wrote: > > paulsw...@gmail.com said: > > I have been working with another time-nut to recover austron 2201a GPS > > receivers and unfortunately I seem to have come to the conclusion that we > > can not get the almanacs to update and will guess this would be the same > > issue with these potentially. > > Is the problem that they don't get an almanac, or that they get the wrong > answer? > > There was a week rollover in one of the main GPS fields several/many years > ago. That ws the first one since GPS started. It made some units give > crazy > answers. (I think they were time only, position was OK.) > > I think you could get around that with some post-processing. I don't > remember anybody doing that. Some units got new firmware. > > > > -- > 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] Temperature stability for Thunderbolt: results
On 29/01/11 13:46, WarrenS wrote: Check with Mark, It is probable in there some where as an undocumented feature, I know the 'MOON MAN' thing is in there. I tried LH's temperature controller as a room thermostat once by connecting it up to a infrared electric heater thru an isolated SCR switch. I figured, why just keep the Tbolt constant when you can keep the whole room constant. Because it will control a Heater and/or a Fan the hair-dryer thing should work also. I was discussing hair-dryer mounted on the antenna mast, somewhat jokeingly naturally. The Tbolt would be sitting warm and snow-free inside the house I guess. 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.
Re: [time-nuts] Temperature stability for Thunderbolt: results
Check with Mark, It is probable in there some where as an undocumented feature, I know the 'MOON MAN' thing is in there. I tried LH's temperature controller as a room thermostat once by connecting it up to a infrared electric heater thru an isolated SCR switch. I figured, why just keep the Tbolt constant when you can keep the whole room constant. Because it will control a Heater and/or a Fan the hair-dryer thing should work also. ws On 28/01/11 13:58, Bob Camp wrote: Hi In the case of the TBolt and LH, the EFC sensitivity can be calibrated against GPS. It's a built in function on version 3.0 and it works pretty well. Over the ranges we're talking about observing for temperature, linearity is not likely to be an issue. I do have a wonderful example of how badly all this can go wrong. Snow has been piling up on the GPS antenna over the last couple days. The plots on all of the GPSDO's are going absolutely nuts. You could correlate stuff to temperature, but the more likely relationship would be to the thickness of the snow. No method is perfect Maybe a LH controlled hair-dryer to burn off some snow? 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.
Re: [time-nuts] Temperature stability for Thunderbolt: results
On 28/01/11 13:58, Bob Camp wrote: Hi In the case of the TBolt and LH, the EFC sensitivity can be calibrated against GPS. It's a built in function on version 3.0 and it works pretty well. Over the ranges we're talking about observing for temperature, linearity is not likely to be an issue. I do have a wonderful example of how badly all this can go wrong. Snow has been piling up on the GPS antenna over the last couple days. The plots on all of the GPSDO's are going absolutely nuts. You could correlate stuff to temperature, but the more likely relationship would be to the thickness of the snow. No method is perfect Maybe a LH controlled hair-dryer to burn off some snow? 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.
