[time-nuts] Realhamradio Forum
Does anyone know what happened to the forum at http://realhamradio.com? It has been in maintenance mode for quite some time. I know that the other web pages are still available, but the forum had additional information and discussion. Even if no new posts are allowed, I hope the forum comes back. The archived posts were a valuable source of information on the Z3801A and variants. Joe Gray W5JG ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Phase noise at 1-100Hz
Hello, I will need to measure the phase noise of a 35MHz oscillator in the range of 1 to 100Hz (well... and also at a higher range but this is no problem), and I would like to know about the different alternatives. I would like not to have to mess too much with mixers and soundcard sampling, if possible :) I think that the HP 5372A with opt 040 is able to do that, is this right and worthy? If so, opt 040 is a pure software option or requires also additional hardware? Would be possible also with a 5370A and software processing of the raw data? Any other alternatives? Thanks! Regards, Javier -- Javier HerreroEMAIL: jherr...@hvsistemas.com Chief Technology Officer HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.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] Phase noise at 1-100Hz
Javier Herrero wrote: Hello, I will need to measure the phase noise of a 35MHz oscillator in the range of 1 to 100Hz (well... and also at a higher range but this is no problem), and I would like to know about the different alternatives. I would like not to have to mess too much with mixers and soundcard sampling, if possible :) I think that the HP 5372A with opt 040 is able to do that, is this right and worthy? If so, opt 040 is a pure software option or requires also additional hardware? Would be possible also with a 5370A and software processing of the raw data? Any other alternatives? Thanks! Regards, Javier The 5372A or 5370A will only suffice if the phase noise is sufficiently high. They are likely to be too noisy by several orders of magnitude for a good crystal oscillator. However they may suffice for something like a noisy ring oscillator or even a low Q LC oscillator. There's also the question of defining the bandwidth so as to avoid folding high frequency phase noise into the measurement when the phase sampling rate is relatively low as it will likely be with a 5370A.. 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] Phase noise at 1-100Hz
El 07/04/2011 10:49, Bruce Griffiths escribió: The 5372A or 5370A will only suffice if the phase noise is sufficiently high. They are likely to be too noisy by several orders of magnitude for a good crystal oscillator. However they may suffice for something like a noisy ring oscillator or even a low Q LC oscillator. There's also the question of defining the bandwidth so as to avoid folding high frequency phase noise into the measurement when the phase sampling rate is relatively low as it will likely be with a 5370A.. Thanks, Bruce, it is something that I was suspecting... both the inherent counter noise and the aliasing of higher frequency phase noise. I would expect that the aliasing would not be very problematic, since phase noise for this oscillator seems to be quite low over 100Hz, at least with respect to the requirements I've. My limits are -25dBc/Hz @ 1Hz, -54dBc/Hz @ 10Hz and -75dBc/Hz @ 100Hz, and really I don't need to measure the exact phase noise at this range, only to test that it is below the limits. Any experience of what would be the measurement limits to be expected with a 5372A? At higher frequencies, I've done some preliminary test with an 8566B and John Miles phase noise plotting software, and I'm quite comfortably inside specs (both measured noise and measurement limit of the 8566B). Best regards, Javier -- Javier HerreroEMAIL: jherr...@hvsistemas.com Chief Technology Officer HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.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] Phase noise at 1-100Hz
Javier Herrero wrote: Hello, I will need to measure the phase noise of a 35MHz oscillator in the range of 1 to 100Hz (well... and also at a higher range but this is no problem), and I would like to know about the different alternatives. I would like not to have to mess too much with mixers and soundcard sampling, if possible :) You probably need to find someone with an HP 3048A or similar outfit. A TSC 5125A will also do the job. The requirement to go below 100 Hz takes a lot of the 'easy' solutions like the 11729C out of contention. I think that the HP 5372A with opt 040 is able to do that, is this right and worthy? If so, opt 040 is a pure software option or requires also additional hardware? Would be possible also with a 5370A and software processing of the raw data? Any other alternatives? Thanks! Regards, Javier The 5372A or 5370A will only suffice if the phase noise is sufficiently high. They are likely to be too noisy by several orders of magnitude for a good crystal oscillator. That was my first thought as well, but the 5370 might be OK for measuring TCXOs and the like. An HP paper from the mid-1970s suggests that it's possible to reach ~-150 dBc/Hz at 1 Hz with contemporary hardware (5345A-based, 2-ns resolution): http://www.hparchive.com/seminar_notes/a-114.pdf They mix down to a low IF before measurement, which they appear to vary in order to get a lower floor at close-in offsets. If nothing else, it should be possible to back the PN spectrum out of an ADEV graph plotted with data from a counter, taking the noise slope into consideration. It would take a lot of hacking (not to mention the effort needed to get hundreds of measurements per second out of the counter, which I also haven't looked into.) There's a more user-friendly app note here: http://www.ko4bb.com/Manuals/HP_Agilent/1%29_HP_App_Notes/HP_AN225_Measuring _Phase_Noise_with_HP_5390A.pdf Could be a reasonable way to measure PN at offsets below 10 or 100 Hz, at least until the higher-order noise slopes invalidate some of the assumptions baked into the software. It wouldn't scale very well to broadband offsets in any event. -- 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] Phase noise at 1-100Hz
John Miles wrote: Javier Herrero wrote: Hello, I will need to measure the phase noise of a 35MHz oscillator in the range of 1 to 100Hz (well... and also at a higher range but this is no problem), and I would like to know about the different alternatives. I would like not to have to mess too much with mixers and soundcard sampling, if possible :) You probably need to find someone with an HP 3048A or similar outfit. A TSC 5125A will also do the job. The requirement to go below 100 Hz takes a lot of the 'easy' solutions like the 11729C out of contention. I think that the HP 5372A with opt 040 is able to do that, is this right and worthy? If so, opt 040 is a pure software option or requires also additional hardware? Would be possible also with a 5370A and software processing of the raw data? Any other alternatives? Thanks! Regards, Javier The 5372A or 5370A will only suffice if the phase noise is sufficiently high. They are likely to be too noisy by several orders of magnitude for a good crystal oscillator. That was my first thought as well, but the 5370 might be OK for measuring TCXOs and the like. An HP paper from the mid-1970s suggests that it's possible to reach ~-150 dBc/Hz at 1 Hz with contemporary hardware (5345A-based, 2-ns resolution): http://www.hparchive.com/seminar_notes/a-114.pdf They mix down to a low IF before measurement, which they appear to vary in order to get a lower floor at close-in offsets. If nothing else, it should be possible to back the PN spectrum out of an ADEV graph plotted with data from a counter, taking the noise slope into consideration. It would take a lot of hacking (not to mention the effort needed to get hundreds of measurements per second out of the counter, which I also haven't looked into.) There's a more user-friendly app note here: http://www.ko4bb.com/Manuals/HP_Agilent/1%29_HP_App_Notes/HP_AN225_Measuring _Phase_Noise_with_HP_5390A.pdf Could be a reasonable way to measure PN at offsets below 10 or 100 Hz, at least until the higher-order noise slopes invalidate some of the assumptions baked into the software. It wouldn't scale very well to broadband offsets in any event. -- john, KE5FX To take full advantage of the resolution of a 5370A it may be necessary to use an external zero crossing detector to reduce the trigger noise to a sufficiently low level with the relatively low beat frequency signal. 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.
[time-nuts] FE-5680A word of caution
Just a word of caution to possible buyers of the Chinese Rubidium FE-5680A boxes. There has been a lot a discussion on the list lately about using the popular FE-5680A as a portable frequency standard and I have being working on using one of the cheap FE-5680A boxes myself. I have found that many of them do not output a useful 10 MHz signal. The 10 MHz output is not close to the expected frequency tolerance. The first of the units that I received puts out a signal at 9,999,945 Hz. The vendor then sent a second unit which puts out a signal at 10,000,025 Hz. The vendor is in China and while he has been willing to work with me by sending a second unit with me paying only postage, the time delay in shipping from China and the cost of postage is prohibitive. What concerns me the most is that the vendor says that both units were tested before shipping. In reviewing the Internet I found several other reports of similar problems with FE-5680A units. The units that I have been working with are FEI FE-5680AFEI P/N 217400-30352-1. These units all require a 5 volt input in addition to the 15 to 18 vdc input and these units are not programmable via an RS-232 port. These units are being advertised by several vendors on E-bay. I am sure that there are good FEI units available but there is no way of telling which are good and which are bad until you get the unit and check it out and if it is bad you may just be stuck with it, Only my experience yours, may be different Jerry ___ time-nuts mailing 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] Transmission line question
If you rephrase the question, it becomes easier: what is the drive impedance I need to use to inject a signal at this point without getting reflection? 25 ohms because the two lines are in parallel at that point. Now, however, signals coming from the other lines will not see a matched impedance when they get there and those will get reflected. That's why you don't see that done very often in RF/microwave circuits. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Don Otknow donald.otk...@gmail.com Sender: time-nuts-boun...@febo.com Date: Wed, 6 Apr 2011 11:00:01 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Transmission line question Hello, If I have a pin with two 50 ohm lines leading in opposite directions from its land (let's say they are arbitrarily long so as to truly look like 50 ohm lines), what is the effective impedance that the pin sees? Thanks, Donald ___ time-nuts mailing 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] FE-5680A word of caution
Le 07/04/2011 16:20, Jerry a écrit : The 10 MHz output is not close to the expected frequency tolerance. The first of the units that I received puts out a signal at 9,999,945 Hz. The vendor then sent a second unit which puts out a signal at 10,000,025 Hz. Could it be the transport conditions that cause the problems? i have noticed that all I get that comes by DHL/UPS/TMS is very cold on arrival. Another possibility might be security screening. I stopped getting film from the US because some got fogged, maybe by x-ray security. ___ time-nuts mailing 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] Webinar on the 21st - LightSquared and GPS: Our Story So Far Hosted by: GPS World
http://www.gpsworld.com/wireless/market-insights-webinars-8423 ___ time-nuts mailing 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] cheap 5V OCXO in 14DIP has about 1E-9 drift per day
I can't speak for anybody else on the list, but if there was an inexpensive converter to get a good stable 10MHz signal from one of the cheap 26MHz OCXOs, I'd sure be interested in building/buying one. -Pete On 04/06/2011 06:23 PM, Greg Broburg wrote: Hi Pete; I bought 10 of these from you already. Im working on a converter that has 26M00 Hz in to 10M00 Hz out. Not sure if that is of any interest but Im putting it on the table. Greg On 4/6/2011 3:56 PM, Peter Loron wrote: Hello, folks. I'm the seller of the 26MHz OCXOs. Please reply off list if you are interested in some. Thanks. -Pete On 04/06/2011 08:58 AM, Oz-in-DFW wrote: Who is the seller? On 3/28/2011 1:40 PM, beale wrote: Just FYI, I'm not sure how this compares to other similar parts, but I'm seeing about +/- 1 ppb (1E-9) frequency drift per 24 hour period from one sample of the Pletronics OHM40480526, which I've had running for about 10 days now. It runs on +5V and after a warmup current of 250 mA for a few seconds, it draws about 60 mA steady state at room temperature. I'm driving the tuning voltage on pin 1 from a separate +5V reference to avoid variations due to heater current shifts. I use a simple resistive trimpot divider to set the voltage, this is not a GPSDO (yet :-). I'm sure most on this list have more refined tastes in oscillators than this one (and probably want 10 MHz instead of 26 MHz), but I thought it noteworthy because it is so cheap. These parts are currently available online for $2 each. I'm not affiliated with the seller. a few more details: http://www.bealecorner.org/best/measure/time/Pletronics-26MHz-OCXO-tuning.pdf http://www.bealecorner.org/best/measure/time/26MHz-osc-notes.txt ___ time-nuts mailing 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] cheap 5V OCXO in 14DIP has about 1E-9 drift per day
A conjugate regenerative divider with 2 parallel (16MHz 10MHz) low Q bandpass filters should suffice. Bruce Peter Loron wrote: I can't speak for anybody else on the list, but if there was an inexpensive converter to get a good stable 10MHz signal from one of the cheap 26MHz OCXOs, I'd sure be interested in building/buying one. -Pete On 04/06/2011 06:23 PM, Greg Broburg wrote: Hi Pete; I bought 10 of these from you already. Im working on a converter that has 26M00 Hz in to 10M00 Hz out. Not sure if that is of any interest but Im putting it on the table. Greg On 4/6/2011 3:56 PM, Peter Loron wrote: Hello, folks. I'm the seller of the 26MHz OCXOs. Please reply off list if you are interested in some. Thanks. -Pete On 04/06/2011 08:58 AM, Oz-in-DFW wrote: Who is the seller? On 3/28/2011 1:40 PM, beale wrote: Just FYI, I'm not sure how this compares to other similar parts, but I'm seeing about +/- 1 ppb (1E-9) frequency drift per 24 hour period from one sample of the Pletronics OHM40480526, which I've had running for about 10 days now. It runs on +5V and after a warmup current of 250 mA for a few seconds, it draws about 60 mA steady state at room temperature. I'm driving the tuning voltage on pin 1 from a separate +5V reference to avoid variations due to heater current shifts. I use a simple resistive trimpot divider to set the voltage, this is not a GPSDO (yet :-). I'm sure most on this list have more refined tastes in oscillators than this one (and probably want 10 MHz instead of 26 MHz), but I thought it noteworthy because it is so cheap. These parts are currently available online for $2 each. I'm not affiliated with the seller. a few more details: http://www.bealecorner.org/best/measure/time/Pletronics-26MHz-OCXO-tuning.pdf http://www.bealecorner.org/best/measure/time/26MHz-osc-notes.txt ___ time-nuts mailing 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] cheap 5V OCXO in 14DIP has about 1E-9 drift per day
On Thu, Apr 7, 2011 at 12:01 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: A conjugate regenerative divider with 2 parallel (16MHz 10MHz) low Q bandpass filters should suffice. Never having used one of those, I'm thinking I'd need two mixers, a 10MHz bandpass filter and a 16 MHz bandpass filter. I'm guessing there would need to be some gain in the system too. How stable are these? Seems to me If the bandpass filters were temperature sensitive the 10MHz output would drift around.What types of filters and mixers are typically used? I wonder if conjugate regenerative divider qualifies as an inexpensive converter -- = 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.
Re: [time-nuts] cheap 5V OCXO in 14DIP has about 1E-9 drift per day
I wonder if conjugate regenerative divider qualifies as an inexpensive converter As we used to say in racing, Speed costs money. How fast do you want to go? CRDs are not particularly expensive, especially when you consider the performance and what it would take to achieve that performance with other solutions -- assuming you need/want that performance (and what kind of time nut would you be if you didn't?). However, I'm not convinced that a cheap (or even free) 26 MHz oscillator plus a downconverter will be less expensive for a given level of performance than just buying a decent 10 MHz OCXO in the first place -- I've bought quite a few very nice ones on-line in the $20-50 range. Mark Sims has suggested some as well (check the list archives). 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] cheap 5V OCXO in 14DIP has about 1E-9 drift per day
Size and power look good so far. Starting point for me is to run the little oscillators for a week and see how they muster up. If that looks good then maybe a few parts from DigiKey to build the filters Greg On 4/7/2011 1:55 PM, Charles P. Steinmetz wrote: I wonder if conjugate regenerative divider qualifies as an inexpensive converter As we used to say in racing, Speed costs money. How fast do you want to go? CRDs are not particularly expensive, especially when you consider the performance and what it would take to achieve that performance with other solutions -- assuming you need/want that performance (and what kind of time nut would you be if you didn't?). However, I'm not convinced that a cheap (or even free) 26 MHz oscillator plus a downconverter will be less expensive for a given level of performance than just buying a decent 10 MHz OCXO in the first place -- I've bought quite a few very nice ones on-line in the $20-50 range. Mark Sims has suggested some as well (check the list archives). 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] cheap 5V OCXO in 14DIP has about 1E-9 drift per day
On 4/7/2011 4:05 PM, Greg Broburg wrote: Size and power look good so far. Starting point for me is to run the little oscillators for a week and see how they muster up. Take a look at Beale's earlier post (be...@bealecorner.com) He's done most of that for you. http://www.bealecorner.org/best/measure/time/26MHz-osc-notes.txt http://www.bealecorner.org/best/measure/time/Pletronics-26MHz-OCXO-tuning.pdf If that looks good then maybe a few parts from DigiKey to build the filters Greg -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ time-nuts mailing 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] FEI FE-5650A and FE-5680A caution
Jerry has described the situation fairly well. You take pot luck, and the Chinese supplier does not know which are which. Out of four units I have, two are remote controllable, one is fixed at (reasonably close to) 10MHz, while the fourth had no output at all. I've since discovered that this last unit has a 1pps output, and I was also able to recover a useful 60MHz output from it by digging inside. If you end up with a fixed ~10MHz unit, it's still useful as a portable reference. It doesn't matter what the exact frequency is, so long as it's stable and repeatable (within your measurement requirements) and has a nice low ageing rate. Murray ZL1BPU ___ time-nuts mailing 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] cheap 5V OCXO in 14DIP has about 1E-9 drift per day
ok, so far so good. Time for some parts. I am thinking that Ill do the 10 with a crystal filter Greg On 4/7/2011 2:28 PM, Oz-in-DFW wrote: On 4/7/2011 4:05 PM, Greg Broburg wrote: Size and power look good so far. Starting point for me is to run the little oscillators for a week and see how they muster up. Take a look at Beale's earlier post (be...@bealecorner.com) He's done most of that for you. http://www.bealecorner.org/best/measure/time/26MHz-osc-notes.txt http://www.bealecorner.org/best/measure/time/Pletronics-26MHz-OCXO-tuning.pdf If that looks good then maybe a few parts from DigiKey to build the filters Greg ___ time-nuts mailing 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] FE-5680A word of caution
On 4/7/2011 8:09 AM, cook michael wrote: Le 07/04/2011 16:20, Jerry a écrit : The 10 MHz output is not close to the expected frequency tolerance. The first of the units that I received puts out a signal at 9,999,945 Hz. The vendor then sent a second unit which puts out a signal at 10,000,025 Hz. Could it be the transport conditions that cause the problems? i have noticed that all I get that comes by DHL/UPS/TMS is very cold on arrival. Another possibility might be security screening. I stopped getting film from the US because some got fogged, maybe by x-ray security. I doubt it. I have one I bought several years ago from a US source that matches all the problem descriptions. I think it is something inherent in this particular version of 5680A (with 5 V needed and no known adjustment method). ___ time-nuts mailing 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] Seller Joon Kyong on eBay now doing business under multiple names...
I just purchased an item from one of my favorite sellers on eBay, someone who ripped me off in the past with a poorly described non working item (but it powered up!) and ridiculously overpriced shipping and I swore I'd never do business with him again. Only then he was doing business under the name jtsele. When I got this latest invoice, something was familiar with the email address, so I searched my email and found fellow time-nuts that have had problems with this individual in the past. Well, buyers beware, he is ALSO doing business as testequip714. In this latest episode, I bought an old esi LCR meter for cheap, but the shipping actually cost more than the unit. Still a good deal (even if it ends up being a parts unit), so I went ahead and bought it anyway. Now I've received a separate invoice for the sales tax. Not a large amount, but I must say I'm REALLY not happy to be doing business with this person again, and still the same old games. So, just beware Joon Kyong = jtsele AND testequip714. AVOID. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A word of caution
Jerry, What reference and measurement system are you using to determine the frequency values you are quoting ? BillWB6BNQ Jerry wrote: Just a word of caution to possible buyers of the Chinese Rubidium FE-5680A boxes. There has been a lot a discussion on the list lately about using the popular FE-5680A as a portable frequency standard and I have being working on using one of the cheap FE-5680A boxes myself. I have found that many of them do not output a useful 10 MHz signal. The 10 MHz output is not close to the expected frequency tolerance. The first of the units that I received puts out a signal at 9,999,945 Hz. The vendor then sent a second unit which puts out a signal at 10,000,025 Hz. The vendor is in China and while he has been willing to work with me by sending a second unit with me paying only postage, the time delay in shipping from China and the cost of postage is prohibitive. What concerns me the most is that the vendor says that both units were tested before shipping. In reviewing the Internet I found several other reports of similar problems with FE-5680A units. The units that I have been working with are FEI FE-5680AFEI P/N 217400-30352-1. These units all require a 5 volt input in addition to the 15 to 18 vdc input and these units are not programmable via an RS-232 port. These units are being advertised by several vendors on E-bay. I am sure that there are good FEI units available but there is no way of telling which are good and which are bad until you get the unit and check it out and if it is bad you may just be stuck with it, Only my experience yours, may be different Jerry ___ time-nuts mailing 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] One heck of a GOOD Ebay seller!
Fellow techies, In light of all the horror stories on Ebay, I thought it would be a Good Thing to call attention to a GOOD seller for a change. If you ever deal with seller ID toomanyamps, do so with absolute confidence! I had bought from him what was advertised as 300 feet of siamese cable (cat5 plus a 16-gauge pair for power), but what arrived was 125 feet. Within less than an hour of my notification, I found a terrific apology for the hassle, and my payment refunded IN FULL despite the fact I'd only asked for $25 back. I am solidly impressed. Happy dealing. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner Head Hardware Heavy, Blue Feather Technologies -- http://www.bluefeathertech.com kyrrin (at) bluefeathertech do/t c=o=m Quid Malmborg in Plano... ___ time-nuts mailing 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] 2201A GPS
Hi; looking for Austron 2201A GPS antenna and manual. Please let me know; I am interested in purchased one. Regards WT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
