Re: [time-nuts] Training period for a Rb clock using GPS
Robert, Thanks that is really helpful. =Abhay On Tue, Jun 1, 2010 at 7:48 PM, Robert Benward rbenw...@verizon.net wrote: Abhay, The microprocessor learns the drift of the oscillator while it is connected, so that when GPS is lost, it can make those corrections in anticipation of drift. The longer it's locked to GPS, the better it learns the drift (more history). Don't confuse the word drift with locked, even when locked, the oscillator is drifting and continuously being corrected. These corrections (the voltage to the EFC or electronic frequency correction) are an indication of the oscillator drift, even though the output is exactly 10MHz. Others can provide links to useful articles. Bob - Original Message - From: Abhay Parekh par...@berkeley.edu To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, June 01, 2010 10:36 PM Subject: [time-nuts] Training period for a Rb clock using GPS Hello, I am a newbie at this, but have been playing around with 2 prs10s. For our application we need to run the clocks without gps, but we do get to sync it to gps *initially* for as long as we want. However, what we've noticed is that when we train it for short periods of time ( 1 hour a day) the clock drifts for a few microseconds a day once we've disconnected gps, but when we train it for say 12 hours, its drift seems to be much less (sub sub microsecond/day). We were wondering why this should be so! I apologize if this is obvious to most of you but I would greatly appreciate your help in shedding some light for us. Thanks! =Abhay ___ time-nuts mailing 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] Flood of low end priced VNAs on FleeBay
Just noticed there is a flood of lower end priced ($5k $5k) VNAs on FleeBay just in case anyone is looking for one. No need to thank me, just buy me one as well :) Steve -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ time-nuts mailing 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] Training period for a Rb clock using GPS
par...@berkeley.edu said: I am a newbie at this, but have been playing around with 2 prs10s. For our application we need to run the clocks without gps, but we do get to sync it to gps *initially* for as long as we want. However, what we've noticed is that when we train it for short periods of time ( 1 hour a day) the clock drifts for a few microseconds a day once we've disconnected gps, but when we train it for say 12 hours, its drift seems to be much less (sub sub microsecond/day). We were wondering why this should be so! Look at it the other way. How long should it take to train it? Let's use rough numbers. There are 1E5 seconds per day. Your few microseconds is 1E-6 seconds. That's an accuracy of 1 part in 1E11. Your sub-sub is 1/10 microsecond or 1E-7 seconds. So that's an accuracy of 1 part in 1E12. The data sheet says: Aging (after 30 days) 5E-11 (monthly) 5E-11 is 50E-12, so that's 2E-12 per day which is what you saw. The data sheet also says: The PRS10 can time-tag an external 1 pps input with 1 ns resolution. These values may be reported back via RS-232, or used to phase-lock the unit to an external reference (such as GPS) with time constants of several hours. There are 4E3 seconds in an hour and 1E9 nanoseconds per second. So in an hour, you can get close to 1 part in 1E12. But that's assuming that the input PPS signal is right-on. There are two types of GPS receivers. Most use a free running clock and generate the PPS pulse with the closest clock edge. They typically have noise on the order of 15-50 ns. Fancy ones will tell you how far off they think it is. The really fancy ones will have a VCXO so they can slew the clock to the right offset. One magic word is hanging bridges. It comes up in discussions occasionally. For lots of info on that area: http://www.gpstime.com/files/PTTI/PTTI_2006.pdf 31 pages, lots of good stuff, aka time sink. More here: http://www.leapsecond.com/pages/vp/heater.htm 2 or 3 screens, good stuff, a quick read. So with only an hour, it's not unreasonable that you are off by a factor of 10, but you might have to get unlucky for a hanging bridge to get you. But there is another factor to consider. What sort of filter is the software using between the PPS input and the knob that adjusts the frequency? More from the data sheet: When tracking an external input, the time constant can be set from 5 minutes to 18 hours. I think the manual says the default is 65K seconds. That's 18 hours. Unless you changed it, that explains why 1 hour wasn't enough. It might get better if you give it more time and/or tweak the time constant if you can only get 12 hours. -- 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] Notes on tight-PLL performance versus TSC 5120A
For those following this strange and wonderful saga: http://www.ke5fx.com/tpll.htm -- 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] Training period for a Rb clock using GPS
Hi The only thing I would add to that is: If your training starts from power up, part of your hour is spent learning something wrong. Most Rb's drift a bit as they stabilize after being turned on. Bob On Jun 2, 2010, at 5:02 AM, Hal Murray wrote: par...@berkeley.edu said: I am a newbie at this, but have been playing around with 2 prs10s. For our application we need to run the clocks without gps, but we do get to sync it to gps *initially* for as long as we want. However, what we've noticed is that when we train it for short periods of time ( 1 hour a day) the clock drifts for a few microseconds a day once we've disconnected gps, but when we train it for say 12 hours, its drift seems to be much less (sub sub microsecond/day). We were wondering why this should be so! Look at it the other way. How long should it take to train it? Let's use rough numbers. There are 1E5 seconds per day. Your few microseconds is 1E-6 seconds. That's an accuracy of 1 part in 1E11. Your sub-sub is 1/10 microsecond or 1E-7 seconds. So that's an accuracy of 1 part in 1E12. The data sheet says: Aging (after 30 days) 5E-11 (monthly) 5E-11 is 50E-12, so that's 2E-12 per day which is what you saw. The data sheet also says: The PRS10 can time-tag an external 1 pps input with 1 ns resolution. These values may be reported back via RS-232, or used to phase-lock the unit to an external reference (such as GPS) with time constants of several hours. There are 4E3 seconds in an hour and 1E9 nanoseconds per second. So in an hour, you can get close to 1 part in 1E12. But that's assuming that the input PPS signal is right-on. There are two types of GPS receivers. Most use a free running clock and generate the PPS pulse with the closest clock edge. They typically have noise on the order of 15-50 ns. Fancy ones will tell you how far off they think it is. The really fancy ones will have a VCXO so they can slew the clock to the right offset. One magic word is hanging bridges. It comes up in discussions occasionally. For lots of info on that area: http://www.gpstime.com/files/PTTI/PTTI_2006.pdf 31 pages, lots of good stuff, aka time sink. More here: http://www.leapsecond.com/pages/vp/heater.htm 2 or 3 screens, good stuff, a quick read. So with only an hour, it's not unreasonable that you are off by a factor of 10, but you might have to get unlucky for a hanging bridge to get you. But there is another factor to consider. What sort of filter is the software using between the PPS input and the knob that adjusts the frequency? More from the data sheet: When tracking an external input, the time constant can be set from 5 minutes to 18 hours. I think the manual says the default is 65K seconds. That's 18 hours. Unless you changed it, that explains why 1 hour wasn't enough. It might get better if you give it more time and/or tweak the time constant if you can only get 12 hours. -- 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] Notes on tight-PLL performance versus TSC 5120A
On 2 June 2010 22:51, John Miles jmi...@pop.net wrote: For those following this strange and wonderful saga: http://www.ke5fx.com/tpll.htm Heath Robinson would be proud :) Very interesting write up John, thanks. 73, Steve -- john, KE5FX -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ time-nuts mailing 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] Flood of low end priced VNAs on FleeBay
Steve Rooke wrote: Just noticed there is a flood of lower end priced ($5k $5k) VNAs on FleeBay just in case anyone is looking for one. No need to thank me, just buy me one as well :) Steve Interesting... be aware that a lot of those 8510s aren't the whole analyzer, just the display or RF section, without the source (sweeper). ANd not just any sweeper will do.. you need one that the 8510 can control over GPIB and that has the right sync in and out. A full 8510 has 3 or 4 boxes (depending on whether it has the s-parameter test set). And, they're getting mighty long in tooth and tricky to fix. I've got a cranky one at work that locks up occasionally, and we've been trying to figure out why. ___ time-nuts mailing 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] Flood of low end priced VNAs on FleeBay
We have a bunch of sweepers at work, and many of the them have died and can't be fixed. The only way they can be repaired is to cannibalize one to fix another, assuming they don't have the same bad module. We have given away an 8510 to a school and have others gathering dust. Rick jimlux wrote: Steve Rooke wrote: Just noticed there is a flood of lower end priced ($5k $5k) VNAs on FleeBay just in case anyone is looking for one. No need to thank me, just buy me one as well :) Steve Interesting... be aware that a lot of those 8510s aren't the whole analyzer, just the display or RF section, without the source (sweeper). ANd not just any sweeper will do.. you need one that the 8510 can control over GPIB and that has the right sync in and out. A full 8510 has 3 or 4 boxes (depending on whether it has the s-parameter test set). And, they're getting mighty long in tooth and tricky to fix. I've got a cranky one at work that locks up occasionally, and we've been trying to figure out why. ___ time-nuts mailing 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] Flood of low end priced VNAs on FleeBay
VNAs are very expensive toys. I have an HP 8753 and was just outbid on a 6 GHz source assembly. :(( Mine has a very complex multi-chip RF Hybrid that has a partial failure, so it only goes to 3 GHz. That's a serious problem with modern high-end microwave gear, if anything dies, you're prettry much screwed. FWIW, -John == We have a bunch of sweepers at work, and many of the them have died and can't be fixed. The only way they can be repaired is to cannibalize one to fix another, assuming they don't have the same bad module. We have given away an 8510 to a school and have others gathering dust. Rick jimlux wrote: Steve Rooke wrote: Just noticed there is a flood of lower end priced ($5k $5k) VNAs on FleeBay just in case anyone is looking for one. No need to thank me, just buy me one as well :) Steve Interesting... be aware that a lot of those 8510s aren't the whole analyzer, just the display or RF section, without the source (sweeper). ANd not just any sweeper will do.. you need one that the 8510 can control over GPIB and that has the right sync in and out. A full 8510 has 3 or 4 boxes (depending on whether it has the s-parameter test set). And, they're getting mighty long in tooth and tricky to fix. I've got a cranky one at work that locks up occasionally, and we've been trying to figure out why. ___ time-nuts mailing 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] preferred GPS
So, do folks have a preferred GPS module to discipline clocks? Clearly some are better than others. I'd like one that will output in NMEA so I can use it to drive some other things as well, but other than that, it has become clear that the Rockwell MicroTrack TU00 just isn't going to cut it as it only locks to 4 satellites, has quite a bit of jitter, doesn't hold a very good 3D lock (+/-100m just isn't good enough for me...) Thanks, 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.
Re: [time-nuts] Flood of low end priced VNAs on FleeBay
I've fix a few pieces of HP equipment simply by re-seating all the PCBs. After all the years, sometimes not in the best humidity environment, those contacts can become intermittant. Re-seating will wipe all the contact surfaces restoring continuity. Bob - Original Message - From: jimlux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, June 02, 2010 9:12 AM Subject: Re: [time-nuts] Flood of low end priced VNAs on FleeBay Steve Rooke wrote: Just noticed there is a flood of lower end priced ($5k $5k) VNAs on FleeBay just in case anyone is looking for one. No need to thank me, just buy me one as well :) Steve Interesting... be aware that a lot of those 8510s aren't the whole analyzer, just the display or RF section, without the source (sweeper). ANd not just any sweeper will do.. you need one that the 8510 can control over GPIB and that has the right sync in and out. A full 8510 has 3 or 4 boxes (depending on whether it has the s-parameter test set). And, they're getting mighty long in tooth and tricky to fix. I've got a cranky one at work that locks up occasionally, and we've been trying to figure out why. ___ time-nuts mailing 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 - www.avg.com Version: 9.0.819 / Virus Database: 271.1.1/2913 - Release Date: 06/02/10 05:57:00 ___ time-nuts mailing 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] preferred GPS
CW25-TIM http://www.navsync.com/docs/CW25_TIM.pdf Stanley - Original Message From: Bob Bownes bow...@gmail.com Sent: Wed, June 2, 2010 11:54:56 AM Subject: [time-nuts] preferred GPS So, do folks have a preferred GPS module to discipline clocks? Clearly some are better than others. I'd like one that will output in NMEA so I can use it to drive some other things as well, but other than that, it has become clear that the Rockwell MicroTrack TU00 just isn't going to cut it as it only locks to 4 satellites, has quite a bit of jitter, doesn't hold a very good 3D lock (+/-100m just isn't good enough for me...) Thanks, 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 mailing 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] On the E - A Spectracom 8164
For those that have a hole in a rack that needs filling Serial # 8164-0590 Item 120578302389 No assoc with the seller at all. -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] OT - HP 5183A Waveform Recorder - is it worth playing with?
Just curious about peoples experiences/thoughts about the HP5183A Waveform Recorder. It's a 2 channel 12 bit digitizer with 512K word memory, 3MHz max sweep rate (no display, HPIB must be used to transfer data). The sweep rate if pretty slow for a lot of applications, but the 12bit of vertical resolutions is intriguing, and both channels can have differential input capability. I've seen some recently for ~ $100.00 but have been unable to find a manual. - Jerome --- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. --- ___ time-nuts mailing 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 - HP 5183A Waveform Recorder - is it worth playing with?
I designed the memory board for that, among other things, and was the project manager for a while. It seemed pretty daring to use DRAM instead of SRAM, and 64k DRAM's at that. When we started, 4k DRAM's were mainstream, and 16k DRAM's were the next big thing. By the time we got into production, 256k DRAM's were ubiquitous at $2. It was a two box product. The digitizer proper and a top box containing a display. There was a private HPIB between the top and bottom boxes, as well as a public HPIB on the top box. Due to pressure from customers, we eventually allowed them to connect to the private HPIB connector on the bottom box and not use the top box at all. The top box had a 9836 computer inside of it running the Pascal operating system. Kind of like newer instruments that have a Windows computer in them. Windows, of course, didn't exist at the time, and even MS-DOS was barely in existence. At that time, I would say the 9836 ran circles around any PC. It had an adaptive sample rate feature that seemed like a good idea at the time, but turned out to be of limited usefulness. BTW, the sample rate is 4 MHz. I don't know what you mean by a 3 MHz sweep rate. Obviously, this wouldn't make sense. You can, of course, now get 12 bit digitizer PCI cards for your PC. Rick Karlquist N6RK Jerome Peters wrote: Just curious about peoples experiences/thoughts about the HP5183A Waveform Recorder. It's a 2 channel 12 bit digitizer with 512K word memory, 3MHz max sweep rate (no display, HPIB must be used to transfer data). The sweep rate if pretty slow for a lot of applications, but the 12bit of vertical resolutions is intriguing, and both channels can have differential input capability. I've seen some recently for ~ $100.00 but have been unable to find a manual. - Jerome --- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. --- ___ time-nuts mailing 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 - HP 5183A Waveform Recorder - is it worth playing with?
$17,800 the good days :-) Did the user i/f to the HPIB ever get published ? -pete On Wed, Jun 2, 2010 at 1:45 PM, Rick Karlquist rich...@karlquist.com wrote: I designed the memory board for that, among other things, and was the project manager for a while. It seemed pretty daring to use DRAM instead of SRAM, and 64k DRAM's at that. When we started, 4k DRAM's were mainstream, and 16k DRAM's were the next big thing. By the time we got into production, 256k DRAM's were ubiquitous at $2. It was a two box product. The digitizer proper and a top box containing a display. There was a private HPIB between the top and bottom boxes, as well as a public HPIB on the top box. Due to pressure from customers, we eventually allowed them to connect to the private HPIB connector on the bottom box and not use the top box at all. The top box had a 9836 computer inside of it running the Pascal operating system. Kind of like newer instruments that have a Windows computer in them. Windows, of course, didn't exist at the time, and even MS-DOS was barely in existence. At that time, I would say the 9836 ran circles around any PC. It had an adaptive sample rate feature that seemed like a good idea at the time, but turned out to be of limited usefulness. BTW, the sample rate is 4 MHz. I don't know what you mean by a 3 MHz sweep rate. Obviously, this wouldn't make sense. You can, of course, now get 12 bit digitizer PCI cards for your PC. Rick Karlquist N6RK Jerome Peters wrote: Just curious about peoples experiences/thoughts about the HP5183A Waveform Recorder. It's a 2 channel 12 bit digitizer with 512K word memory, 3MHz max sweep rate (no display, HPIB must be used to transfer data). The sweep rate if pretty slow for a lot of applications, but the 12bit of vertical resolutions is intriguing, and both channels can have differential input capability. I've seen some recently for ~ $100.00 but have been unable to find a manual. - Jerome --- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. --- ___ time-nuts mailing 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] On the E - A Spectracom 8164
Hi Pete -- ISTR we had one of those (or a close relative) in the Tek Dayton Svc Ctr back in the late 70s-early 80s. It always scares me a bit when a cal lab sells off stuff as parts/repair rather than just fixing it. Gotta wonder what parts are unobtanium. -ls- Pete Lancashire p...@petelancashire.com wrote: For those that have a hole in a rack that needs filling Serial # 8164-0590 Item 120578302389 No assoc with the seller at all. -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 mailing 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 - HP 5183A Waveform Recorder - is it worth playing with?
Pete Lancashire wrote: $17,800 the good days :-) Did the user i/f to the HPIB ever get published ? -pete I'm not sure if it got published or was leaked to certain customers. I vaguely remember having to document it. I just remembered that the HPIB phy chip used was made by TI and had a bug in it. TI refused to fix the bug. (The other two vendors of phy chips also had bugs). If you made continuous measurements, about once a day it would go into serial poll mode and hang. However, I believe the fault was in the top box. 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.
Re: [time-nuts] OT - HP 5183A Waveform Recorder - is it worth playing with?
pity not a stand alone instrument, I was offered one for free and have seen them on the E for as little as $20. -pete On Wed, Jun 2, 2010 at 2:25 PM, Rick Karlquist rich...@karlquist.com wrote: Pete Lancashire wrote: $17,800 the good days :-) Did the user i/f to the HPIB ever get published ? -pete I'm not sure if it got published or was leaked to certain customers. I vaguely remember having to document it. I just remembered that the HPIB phy chip used was made by TI and had a bug in it. TI refused to fix the bug. (The other two vendors of phy chips also had bugs). If you made continuous measurements, about once a day it would go into serial poll mode and hang. However, I believe the fault was in the top box. 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.
Re: [time-nuts] On the E - A Spectracom 8164
In a message dated 02/06/2010 22:25:53 GMT Daylight Time, lar...@teamlarry.com writes: ISTR we had one of those (or a close relative) in the Tek Dayton Svc Ctr back in the late 70s-early 80s. It always scares me a bit when a cal lab sells off stuff as parts/repair rather than just fixing it. Gotta wonder what parts are unobtanium. --- I don't recall there being anything in the 8164 that's impossible to find, all reasonably common components and the complete A4 output board is very similar, perhaps identical, to the A4 board in the 8140 distribution amp. I suspect it's more a case of what's financially worthwhile, if they haven't got a matching antenna for example it starts to be a pain acquiring or building one when they might not consider there's much potential profit in it anyway. A possible gotcha though might be if the internal lead acid batteries have been neglected and have leaked. Aside from the above, the 8164 is a nicely made unit and I've been promising myself for ages that I'll knock up an antenna and see how mine performs with MSF in the UK, but, as usual, I haven't gotten round to it either:-) As far as I know the manual is still available on the Spectracom web site but if not I've got versions 3.0 and 3.1 and happy to share. 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.
Re: [time-nuts] Motorola GPS Z3801A
Rex, I measured them attached to a valid RS-232 port. I am dismantling the unit and I will be checking the voltages right at the chip. Bob - Original Message - From: Rex r...@sonic.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, June 02, 2010 12:49 AM Subject: Re: [time-nuts] Motorola GPS Z3801A Robert Benward wrote: Matt, It's been modified. I was told that when I bought it, and confirmed it myself. I don't get the right voltages; I need a new RS-232 interface chip. Bob I never heard an answer about if you had measured the voltages at the Z3801A connector open circuit (nothing attached that could be loading or driving what you are measuring). ___ time-nuts mailing 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] Motorola GPS Z3801A
Matt, I should know better than to forget to get the guy's phone number or address, flea markets are notorious dumping grounds for garbage. Bob - Original Message - From: Matthew Kaufman matt...@matthew.at To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, June 02, 2010 12:50 AM Subject: Re: [time-nuts] Motorola GPS Z3801A Robert Benward wrote: Matt, It's been modified. I was told that when I bought it, and confirmed it myself. I don't get the right voltages; I need a new RS-232 interface chip. Did you double-check the mod to ensure that the 0-ohm chip resistors came off in addition to the jumper changes? I've managed to have a dead 3801A due to a bad mod I did once on one of my 9 or so units, which is why this is always what comes to mind now. Matthew Kaufman ___ time-nuts mailing 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] Notes on tight-PLL performance versus TSC 5120A
John Miles wrote: For those following this strange and wonderful saga: http://www.ke5fx.com/tpll.htm -- 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. The problem with that page is that you show the original NIST implementation which actually produces valid ADEV measures whereas Warren's implementation omits the crucial integration/averaging (his figurative handwaving antics don't change this) and hence actually has a different phase noise frequency response than that of the filter implied by the definition of AVAR. Why Warren omits this crucial step when all it requires is a little digital signal processing as all the required information is available from the sampled EFC voltage remains a mystery. The method as implemented by Warren produces a frequency stability metric which may be useful for comparing the stability of some sources, however it does not measure ADEV. Under a restricted set of circumstances such as when white phase noise or drift dominate the measures so calculated my be close to the measured ADEV obtained by a method wth the correct response to the various phase noise frequency components, however this doesnt mean that the measures are actually ADEV measures it merely means that the phase noise frequency components in the region where the frequency response of the 2 methods differ significantly, are not significant. Bruce ___ time-nuts mailing 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] Fiberoptic 10MHz link
I have access to my roof and above through a trap door I had installed when we built the house. Also have AC in the attic. I've been reluctant to put a GPS up there with a direct link to the shack and computers, etc. Has anyone done a simple circuit for conversion from a 10 MHz signal into, say, TOSLINK or such and then back for a galvanic break? I realize that I'll be adding some delay and jitter, but for frequency locking shouldn't be a problem. Looks like it isn't too big a problem to throw something together, but if it has be done.. N0UU ___ time-nuts mailing 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 - HP 5183A Waveform Recorder - is it worth playing with?
Unfortunately not worth messing with. I have the 5180 in the basement (At least thats what I think it is. Been a long time) There is one heck of a switching supply and over age it becomes troublesome. It may be $20 on epay, but shippings $100 On Wed, Jun 2, 2010 at 5:34 PM, Pete Lancashire p...@petelancashire.comwrote: pity not a stand alone instrument, I was offered one for free and have seen them on the E for as little as $20. -pete On Wed, Jun 2, 2010 at 2:25 PM, Rick Karlquist rich...@karlquist.com wrote: Pete Lancashire wrote: $17,800 the good days :-) Did the user i/f to the HPIB ever get published ? -pete I'm not sure if it got published or was leaked to certain customers. I vaguely remember having to document it. I just remembered that the HPIB phy chip used was made by TI and had a bug in it. TI refused to fix the bug. (The other two vendors of phy chips also had bugs). If you made continuous measurements, about once a day it would go into serial poll mode and hang. However, I believe the fault was in the top box. 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.
Re: [time-nuts] Fiberoptic 10MHz link
An interesting idea. I have thought about using network SFP interfaces to isolate the reference in the basement from all else. Tinkered with the network sfps but as it turns out they are actually somewhat complicated and as I recall ecl based. How to convert the freq standard out sinewave to ecl and not introduce lots of trouble. So for the moment all is 75 ohm coax and dumb simple stupid splitters. On Wed, Jun 2, 2010 at 8:13 PM, lstosk...@cox.net wrote: I have access to my roof and above through a trap door I had installed when we built the house. Also have AC in the attic. I've been reluctant to put a GPS up there with a direct link to the shack and computers, etc. Has anyone done a simple circuit for conversion from a 10 MHz signal into, say, TOSLINK or such and then back for a galvanic break? I realize that I'll be adding some delay and jitter, but for frequency locking shouldn't be a problem. Looks like it isn't too big a problem to throw something together, but if it has be done.. N0UU ___ time-nuts mailing 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] Notes on tight-PLL performance versus TSC 5120A
As Bruce says It remains a mystery to him why this works. Not one of my best skills, but I'll try to explain it once again. Now that they see it works, maybe someone else will be able to put this into words that Bruce will be able to finally understand. The only requirement needed for the Frequency data log to be give correct ADEV readings, is to get good, Averaged, integrated, Frequency data, with no dead time, and no aliasing, over the tau0 time period. Each Tau0 Frequency sample is ideally completely independent from all others. If it can do one right then it can get them ALL right. In a single tau0 sample there is NO SUCH THING as a certain type of long term noise, Just the average freq over that single time period. The crucial integration/averaging to get good tau0 data, that Bruce can not see for some unknown reason, is done with an analog filter set to about the Tau0 Freq and by oversampling at about about a 10 to one ratio, and averaging the oversampled frequency readings down to tau0. It is not perfect, but plenty close enough for the plot to match the output of the TSC 5120A over the whole tau range. There are a few other subtle details on how to insure that aliasing and over filtering do not become a problem, but first things first, one needs to understand how the integration is being done. The integration secret (which is no secret to anyone but Bruce) is to analog filter, Oversample, then average the Frequency data at a rate much faster than the tau0 data rate. That alone should be enough information for any knowledgeable designer to understand. ws ps) Do note, I'm working with Frequency here and not phase, that may be what is confusing some. *** The problem with that page is that you show the original NIST implementation which actually produces valid ADEV measures whereas Warren's implementation omits the crucial integration/averaging (his figurative handwaving antics don't change this) and hence actually has a different phase noise frequency response than that of the filter implied by the definition of AVAR. Why Warren omits this crucial step when all it requires is a little digital signal processing as all the required information is available from the sampled EFC voltage remains a mystery. The method as implemented by Warren produces a frequency stability metric which may be useful for comparing the stability of some sources, however it does not measure ADEV. Under a restricted set of circumstances such as when white phase noise or drift dominate the measures so calculated my be close to the measured ADEV obtained by a method wth the correct response to the various phase noise frequency components, however this doesnt mean that the measures are actually ADEV measures it merely means that the phase noise frequency components in the region where the frequency response of the 2 methods differ significantly, are not significant. Bruce * John Miles wrote: For those following this strange and wonderful saga: http://www.ke5fx.com/tpll.htm -- 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] Fiberoptic 10MHz link
Hi A $3 RF transformer should do the trick. You can put in a couple of them if you are really concerned. The optical stuff will work. It's pretty expensive if you want something quiet enough to be useful. A jitter of 0.1 UI is considered ok for moving data. A 36 degree phase modulation (same thing) on your frequency standard is not going to do very well. More or less, you need a link that would do ok on very fast data to give you a decent frequency reference at the other end without running a clean up loop in the basement. Bob On Jun 2, 2010, at 8:13 PM, lstosk...@cox.net lstosk...@cox.net wrote: I have access to my roof and above through a trap door I had installed when we built the house. Also have AC in the attic. I've been reluctant to put a GPS up there with a direct link to the shack and computers, etc. Has anyone done a simple circuit for conversion from a 10 MHz signal into, say, TOSLINK or such and then back for a galvanic break? I realize that I'll be adding some delay and jitter, but for frequency locking shouldn't be a problem. Looks like it isn't too big a problem to throw something together, but if it has be done.. N0UU ___ time-nuts mailing 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] Fiberoptic 10MHz link
N0UU, At 10MHz, a very robust toroid wound transformer is easy to construct and can provide several KV of isolation, with little signal loss. Any low loss powder iron core and 15 or 20 turns of silicone rubber insulated wire will suffice for signals up to 1 or 2 Vrms. Pete Rawson On Jun 2, 2010, at 6:13 PM, lstosk...@cox.net lstosk...@cox.net wrote: I have access to my roof and above through a trap door I had installed when we built the house. Also have AC in the attic. I've been reluctant to put a GPS up there with a direct link to the shack and computers, etc. Has anyone done a simple circuit for conversion from a 10 MHz signal into, say, TOSLINK or such and then back for a galvanic break? I realize that I'll be adding some delay and jitter, but for frequency locking shouldn't be a problem. Looks like it isn't too big a problem to throw something together, but if it has be done.. N0UU ___ time-nuts mailing 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] Lady Heather's D. O. program
Hello Time nuts and good evening; I have been using this program with my TB. for a while now and just wanted to thank Mark Sims who I believe is responsible for his marvelous work of art. Best regards, Bob K7HBG ___ time-nuts mailing 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's D. O. program
I second that! At 03-06-10, you wrote: Hello Time nuts and good evening; I have been using this program with my TB. for a while now and just wanted to thank Mark Sims who I believe is responsible for his marvelous work of art. -- Raj, VU2ZAP Bangalore, India. ___ time-nuts mailing 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] Notes on tight-PLL performance versus TSC 5120A
WarrenS wrote: As Bruce says It remains a mystery to him why this works. It doesnt, it only appears to in a very restricted set of circumstances. Not one of my best skills, but I'll try to explain it once again. Now that they see it works, maybe someone else will be able to put this into words that Bruce will be able to finally understand. The only requirement needed for the Frequency data log to be give correct ADEV readings, is to get good, Averaged, integrated, Frequency data, with no dead time, and no aliasing, over the tau0 time period. Each Tau0 Frequency sample is ideally completely independent from all others. If it can do one right then it can get them ALL right. In a single tau0 sample there is NO SUCH THING as a certain type of long term noise, Just the average freq over that single time period. Misleading as usual, your knowledge of statistics is woefully inadequate leading to incorrect conclusions. The crucial integration/averaging to get good tau0 data, that Bruce can not see for some unknown reason, is done Only in your imagination. with an analog filter set to about the Tau0 Freq and by oversampling at about about a 10 to one ratio, and averaging the oversampled frequency readings down to tau0. That doesn't work as it has the wrong transfer function. It is not perfect, but plenty close enough for the plot to match the output of the TSC 5120A over the whole tau range. There are a few other subtle details on how to insure that aliasing and over filtering do not become a problem, but first things first, one needs to understand how the integration is being done. Sloppy and misleading explanation as usual. The integration secret (which is no secret to anyone but Bruce) is to analog filter, Oversample, then average the Frequency data at a rate much faster than the tau0 data rate. Which again is misleading as you specify neither the averaging method nor the analog filter. That alone should be enough information for any knowledgeable designer to understand. Its not and you should know that it isnt. You draw conclusions that are neither supported by measurement nor theory. ws ps) Do note, I'm working with Frequency here and not phase, that may be what is confusing some. When will you understand that phase differences and differences of average frequency (unit weight to frequency measures over the sampling interval zero weight outside) are equivalent. *** The problem with that page is that you show the original NIST implementation which actually produces valid ADEV measures whereas Warren's implementation omits the crucial integration/averaging (his figurative handwaving antics don't change this) and hence actually has a different phase noise frequency response than that of the filter implied by the definition of AVAR. Why Warren omits this crucial step when all it requires is a little digital signal processing as all the required information is available from the sampled EFC voltage remains a mystery. The method as implemented by Warren produces a frequency stability metric which may be useful for comparing the stability of some sources, however it does not measure ADEV. Under a restricted set of circumstances such as when white phase noise or drift dominate the measures so calculated my be close to the measured ADEV obtained by a method wth the correct response to the various phase noise frequency components, however this doesnt mean that the measures are actually ADEV measures it merely means that the phase noise frequency components in the region where the frequency response of the 2 methods differ significantly, are not significant. Bruce * John Miles wrote: For those following this strange and wonderful saga: http://www.ke5fx.com/tpll.htm -- 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. ___ time-nuts mailing 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] Notes on tight-PLL performance versus TSC 5120A
The integration secret (which is no secret to anyone but Bruce) is to analog filter, Oversample, then average the Frequency data at a rate much faster than the tau0 data rate. Which again is misleading as you specify neither the averaging method nor the analog filter. I can't speak for the analog side as I never saw a schematic of the PLL, but it may be worthwhile to point out that the averaging code in question is in SOURCE_DI154_proc() in ti.cpp, which is installed with http://www.ke5fx.com/gpib/setup.exe . This is my code, not Warren's. It does a simple boxcar average on phase-difference data, the same as my TSC 5120 acquisition routine does. Previous tests indicated that simple averaging yields a good match to most ADEV graphs on TSC's LCD display, so I used it for the PLL DAQ code as well. I also tried a Kaiser-synthesized FIR kernel for decimating the incoming TSC data, but found that its conformance against the TSC's display was worse than what I saw with the simple average. More work needs to be done here. When will you understand that phase differences and differences of average frequency (unit weight to frequency measures over the sampling interval zero weight outside) are equivalent. One subtlety is the question of whether to average (or otherwise filter) the DAQ voltage readings immediately after they're acquired and linearly scaled to frequency-difference values, versus after conversion of the frequency-difference values to phase differences. I found that the best agreement with the TSC plots was obtained by doing the latter: val = (read and scale the DAQ voltage) // val is now a frequency difference // averaging val here yields somewhat higher // sigma(tau) values in the first few bins // after tau0 val = last_phase + (val / DI154_RATE_HZ); last_phase = val; // val is now a phase difference // averaging val here matches the TSC better The difference is not huge but it's readily noticeable. This is subtly disturbing because the RC filter before the DAQ *does* integrate the frequency-difference data directly. If it's correct to band-limit the frequency-to-voltage data in the last analog stage of the pipeline, it should be correct to do it in the first digital stage, I'd think. Further complicating matters is the question of whether the TSC 5120A's filtering process is really all that 'correct,' itself. When they downsample their own data by a large fraction, e.g. when you select tau0=100 msec / NEQ BW = 5 Hz, there is often a slight droop near tau0 that does not correspond to anything visible at higher rates. To some extent we may be attempting to match someone else's bug. At any rate I've run out of time/inclination to pursue it, at least for now. The SOURCE_DI154_proc() routine in TI.CPP is open for inspection and modification by any interested parties, lines 6753-7045 in the current build. :) Warren has his hardware back now, and would presumably be able to try any modifications. -- 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] Flood of low end priced VNAs on FleeBay
Richard (Rick) Karlquist wrote: We have a bunch of sweepers at work, and many of the them have died and can't be fixed. The only way they can be repaired is to cannibalize one to fix another, assuming they don't have the same bad module. We have given away an 8510 to a school and have others gathering dust. that's what we've found.. ___ time-nuts mailing 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] Flood of low end priced VNAs on FleeBay
J. Forster wrote: VNAs are very expensive toys. I have an HP 8753 and was just outbid on a 6 GHz source assembly. :(( Mine has a very complex multi-chip RF Hybrid that has a partial failure, so it only goes to 3 GHz. That's a serious problem with modern high-end microwave gear, if anything dies, you're prettry much screwed. Even something as old as an 8510 has the same problem. It's not like you can get spare boards, assuming you can even figure which board is dead. Or, replace parts on the boards/modules. OTOH, for 3GHz, less than a kilobuck buys you a pretty impressive PC peripheral style VNA. Yeah, not the performance of a modern PNA, but probably better than sweeper/141T or even an 8510 class box in some cases. ___ time-nuts mailing 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] Notes on tight-PLL performance versus TSC 5120A
John Miles wrote: The integration secret (which is no secret to anyone but Bruce) is to analog filter, Oversample, then average the Frequency data at a rate much faster than the tau0 data rate. Which again is misleading as you specify neither the averaging method nor the analog filter. I can't speak for the analog side as I never saw a schematic of the PLL, but it may be worthwhile to point out that the averaging code in question is in SOURCE_DI154_proc() in ti.cpp, which is installed with http://www.ke5fx.com/gpib/setup.exe . This is my code, not Warren's. It does a simple boxcar average on phase-difference data, the same as my TSC 5120 acquisition routine does. Previous tests indicated that simple averaging yields a good match to most ADEV graphs on TSC's LCD display, so I used it for the PLL DAQ code as well. I also tried a Kaiser-synthesized FIR kernel for decimating the incoming TSC data, but found that its conformance against the TSC's display was worse than what I saw with the simple average. More work needs to be done here. When will you understand that phase differences and differences of average frequency (unit weight to frequency measures over the sampling interval zero weight outside) are equivalent. One subtlety is the question of whether to average (or otherwise filter) the DAQ voltage readings immediately after they're acquired and linearly scaled to frequency-difference values, versus after conversion of the frequency-difference values to phase differences. I found that the best agreement with the TSC plots was obtained by doing the latter: val = (read and scale the DAQ voltage) // val is now a frequency difference // averaging val here yields somewhat higher // sigma(tau) values in the first few bins // after tau0 val = last_phase + (val / DI154_RATE_HZ); last_phase = val; This appears to use a rectangular approximation to the required integral. A trapezoidal or even Simpson's rule integration technique should be more accurate for a given sample rate. One could even try a higher order polynomial fit to the sample points, however this isnt the optimum technique to use. If one uses WKS interpolation to reconstruct the continuous frequency vs time function and integrates the result for a finite time interval (Tau0) then one ends up with a digital filter with infinite number of terms. Since an infinite number of samples is required to do this using a suitable window function is probably advisable. The paper (below) illustrates how AVAR etc can be calculated from the sampled frequency difference data using DFT techniques: http://hal.archives-ouvertes.fr/docs/00/37/63/05/PDF/alaa_p1_v4a.pdf // val is now a phase difference // averaging val here matches the TSC better The difference is not huge but it's readily noticeable. This is subtly disturbing because the RC filter before the DAQ *does* integrate the frequency-difference data directly. If it's correct to band-limit the frequency-to-voltage data in the last analog stage of the pipeline, it should be correct to do it in the first digital stage, I'd think. The RC filter doesnt accurately integrate the frequency difference over time interval Tau0. Further complicating matters is the question of whether the TSC 5120A's filtering process is really all that 'correct,' itself. When they downsample their own data by a large fraction, e.g. when you select tau0=100 msec / NEQ BW = 5 Hz, there is often a slight droop near tau0 that does not correspond to anything visible at higher rates. To some extent we may be attempting to match someone else's bug. This is the result of the choice of the low pass filter bandwidth made by the designers. The filter bandwidth increases as Tau0 decreases. The traditional analyses of the dependence of AVAR on bandwidth of this filter assume a brickwall filter. At any rate I've run out of time/inclination to pursue it, at least for now. The SOURCE_DI154_proc() routine in TI.CPP is open for inspection and modification by any interested parties, lines 6753-7045 in the current build. :) Warren has his hardware back now, and would presumably be able to try any modifications. -- 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. Bruce ___ time-nuts mailing 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 - HP 5183A Waveform Recorder - is it worth playing with?
You can, of course, now get 12 bit digitizer PCI cards for your PC. Or heck, eval boards for 12 bit ADCs that have USB interfaces.. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
