Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these
On Tue, Dec 20, 2011 at 1:08 PM, Chuck Forsberg WA7KGX N2469R c...@omen.com wrote: It took about 32 minutes to make lock. Before that it was cycling between about +75 and -200 Hz. That seems rather slow - I just checked the 4 units I have here (D/C 0321, 0330, 0342 and 0349) and they all locked in under 3:30 from cold - the fastest was just under 2:58. Regards, 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.
Re: [time-nuts] My Racal-Dana 1992
Don wrote: This is typical for an underdamped second order servo. The oscillation is the penalty for a shorter settling time. A critically damped system would not oscillate, but approach the final value smoothly in a slightly longer time. It may have been designed for a slight overshoot... Yes, I understand and I don't doubt that it is performing as designed. My point was that most crystal oscillator frequency adjustments (at least, the ones that I have seen) are open-loop (variable capacitor or pot to a varactor diode). Finding the fine frequency control apparently in a servo loop was a surprise. And it cannot be a PLL or FLL, because there is only the one reference -- the one you are adjusting. Since the startup dynamics are so similar to the fine frequency adjustment dynamics (not to mention that the oven loop is pretty much the only possible servo in the oscillator), the evidence appears strong that the fine frequency adjustment is an oven temperature adjustment. Unless there is something truly diabolical going on inside a 9462. 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] Ebay FE-5680A Rb I see the price has gone up for these
FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. 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] New precision watch
On Mon, 19 Dec 2011 19:12:43 -0500 Chuck Harris cfhar...@erols.com wrote: There is nothing inherent in temperature correcting a clock that should take significantly more power than would be used in a normal watch chip. Measuring the temperature would be the most power hungry operation, I would suspect... but fortunately that doesn't have to be done all that often, perhaps once per minute. Juup, it definitly should not draw much power. I own a Tissot T-Touch (first gen) that goes wrong less than 5s/y, ie it's definitly temperature compensated. Battery lifetime is several years (i actually dont know because i had to bring it back for repairs in shorter intervals than the battery holds) Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran receiver
I have uploaded the article about the LORAN receiver. Search for LORAN http://www.ko4bb.com/manuals/ Didier KO4BB --Original Message-- From: Richard W. Solomon To: Didier Juges via Gmail ReplyTo: Richard W. Solomon Subject: Re: [time-nuts] Loran receiver Sent: Dec 19, 2011 10:24 AM I looked at the August, 1994 issue quickly and didn't see anything about a LORAN receiver. Was it under something else ? 73, Dick, W1KSZ -Original Message- From: shali...@gmail.com Sent: Dec 18, 2011 8:52 PM To: Time-Nuts time-nuts@febo.com Subject: [time-nuts] Loran receiver I have a single board Loran receiver to give away for the cost of shipping. It was described in 73 Magazine of August 1994. There is no case or display, just a PWB. It needs an antenna, +5 and +15V supplies. The antenna cable has been removed long ago. Its easy to solder another cable in its place. I bought it at that time and had it working briefly before I lost interest in it. I have a copy of the original article which described how to interface it to a PC's serial port. I hate to just throw it away, even though that is probably all there is to do with it. If anyone is interested, I will ship it in one of these USPS boxes, or maybe a padded envelop. Not sure how much they charge. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Sent from my BlackBerry Wireless thingy while I do other things... ___ time-nuts mailing 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] Ebay FE-5680A Rb I see the price has gone up for these
-- From: Rex r...@sonic.net Sent: Tuesday, December 20, 2011 1:10 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. regards Nigel GM8PZR Nigel I trust that you are aware that some models of the FE-5680A only require the 15 volt/1.7Amp. supply. In fact connecting a 5 volt supply to the units that are programmable can cause damage ! Roy ___ time-nuts mailing 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] Ebay FE-5680A Rb I see the price has gone up for these
Ebay 300638681652 is more like it. Just add a 7805 to get your 5 volts. For that kind of price it's almost cheaper to buy than to pay for gas plus time for me to go to my storage unit and grab one (maybe that's a lesson for what I should even save!). In my intended application though, there is already +5 and +15 available. Peter On 12/20/2011 10:13 AM, Roy Phillips wrote: -- From: Rex r...@sonic.net Sent: Tuesday, December 20, 2011 1:10 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. regards Nigel GM8PZR Nigel I trust that you are aware that some models of the FE-5680A only require the 15 volt/1.7Amp. supply. In fact connecting a 5 volt supply to the units that are programmable can cause damage ! Roy ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1415 / Virus Database: 2108/4092 - Release Date: 12/20/11 ___ time-nuts mailing 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] Ebay FE-5680A Rb I see the price has gone up for these
Mine requires the 5 volt supply at 340 ma. Are there nay manufacturer's instructions about mounting, ventilating, or heat sinking these units? My current thinking is to mount it on standoffs on the back of the chassis that houses my Thunderbolt. Perhaps I should place it where it can warm up Princess. (Notice the magnet on top of the oscillator.) On 12/20/2011 07:13 AM, Roy Phillips wrote: -- From: Rex r...@sonic.net Sent: Tuesday, December 20, 2011 1:10 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. regards Nigel GM8PZR Nigel I trust that you are aware that some models of the FE-5680A only require the 15 volt/1.7Amp. supply. In fact connecting a 5 volt supply to the units that are programmable can cause damage ! Roy ___ time-nuts mailing 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 attachment: FE-CAT.JPG___ time-nuts mailing 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] Ebay FE-5680A Rb I see the price has gone up for these
340mA seems really high - all the ones I've seen take about 90mA - and I would strongly recommend putting in on a heatsink, or at least bolting it directly to the chassis. In my experience, they don't actually malfunction when operated without one, but the housing gets very hot (and, presumably, the insides get hotter still) - after 24h running sitting on a foam mouse mat open to the air, the case hit about 59c - I can't help thinking that isn't going to be good for the long-term health of the unit. Regards, Pete On Wed, Dec 21, 2011 at 12:03 AM, Chuck Forsberg WA7KGX N2469R c...@omen.com wrote: Mine requires the 5 volt supply at 340 ma. Are there nay manufacturer's instructions about mounting, ventilating, or heat sinking these units? My current thinking is to mount it on standoffs on the back of the chassis that houses my Thunderbolt. Perhaps I should place it where it can warm up Princess. (Notice the magnet on top of the oscillator.) On 12/20/2011 07:13 AM, Roy Phillips wrote: -- From: Rex r...@sonic.net Sent: Tuesday, December 20, 2011 1:10 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. regards Nigel GM8PZR Nigel I trust that you are aware that some models of the FE-5680A only require the 15 volt/1.7Amp. supply. In fact connecting a 5 volt supply to the units that are programmable can cause damage ! Roy ___ time-nuts mailing 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these
Agreed 340mA seems too high, mine takes 87mA. There has been much comment on [time_nuts] about the temperature of these units varying from 'let 'em get hot' to 'must heatsink'. In my experience items that require a heatsink have a milled flat surface to mount to a sink, not a thin case that would only touch in places. Furthermore I didn't think fiberglass circuit board was famous for its heat conducting properties. No sign of any heat transfer compound either. So do I conclude they need a bit of cooling? I agree with you Pete and would really like to know what the makers say about all this! Best wishes, John. On 20 Dec 2011, at 16:22, Peter Bell wrote: 340mA seems really high - all the ones I've seen take about 90mA - and I would strongly recommend putting in on a heatsink, or at least bolting it directly to the chassis. In my experience, they don't actually malfunction when operated without one, but the housing gets very hot (and, presumably, the insides get hotter still) - after 24h running sitting on a foam mouse mat open to the air, the case hit about 59c - I can't help thinking that isn't going to be good for the long-term health of the unit. Regards, Pete On Wed, Dec 21, 2011 at 12:03 AM, Chuck Forsberg WA7KGX N2469R c...@omen.com wrote: Mine requires the 5 volt supply at 340 ma. Are there nay manufacturer's instructions about mounting, ventilating, or heat sinking these units? My current thinking is to mount it on standoffs on the back of the chassis that houses my Thunderbolt. Perhaps I should place it where it can warm up Princess. (Notice the magnet on top of the oscillator.) On 12/20/2011 07:13 AM, Roy Phillips wrote: -- From: Rex r...@sonic.net Sent: Tuesday, December 20, 2011 1:10 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. regards Nigel GM8PZR Nigel I trust that you are aware that some models of the FE-5680A only require the 15 volt/1.7Amp. supply. In fact connecting a 5 volt supply to the units that are programmable can cause damage ! Roy ___ time-nuts mailing 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Efratom FRK - no 10Mhz oscillator
A little help, pls, from the more experienced. This is my first time into one of these .I have listened and learned from you' all for some time, though. It can be intimidating in this close-packed FRK. I am trying to bring up an Efratom FRK I have had for a while. The 10 MHz oscillator does not start upon power on. Any ideas where to look? I have done the following: * I have it opened-up and applied 24vDC and the current starts up initially at 1.45 amp and slowly goes down to ~.6- .8 amps. * Since I have no 10 MHz output, .so I looked at the oscillator board and nothing out from it. * The 17 volt dc supply-rail is good, and the VCO input signal to the varacter control-circuitry is constantly ramping up and down slowly between ~1volt and ~15 volts. * All the transistors in the oscillator circuit seem ok with a VOM, ..and when I purposely inject a 10Mhz signal into the collector of the 'oscillator' transistor (Q3), .I do get a clean 10Mhz out of the unit (of course it won't lock), .and I haven't even been into the rest of the unit. * I think the crystal is bad, .I took the cover off the crystal oven, it 'looks' ok, . and the crystal heater in the oven is heating and regulating. Any ideas? .does the 10 MHz crystal in these have a history of failing? Can I get a replacement crystal for it easily? How can I test this crystal for pass/fail? Thanks, .just my first test of the waters as a fledging time-nut. Don Lewis Austin, TX ___ time-nuts mailing 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] Ebay FE-5680A Rb I see the price has gone up for these
A milled flat surface and/or thermal paste is not required for heat transfer, it just makes it better. There must be some removal of heat; consider that to reach thermal equilibrium the heat flow out of the unit must match the power absorbed. It seems that about 12 watts is going in, so eventually 12 watts must be flowing out if the temperature is to remain steady. I would not want mine to run at 60C, I would rather it be at a more reasonable 35-40C on the baseplate, just for the electronics. I am going to mount mine to an existing aluminum panel in my target unit using the provided mounting holes and be done with it. Peter On 12/20/2011 12:18 PM, John Howell wrote: Agreed 340mA seems too high, mine takes 87mA. There has been much comment on [time_nuts] about the temperature of these units varying from 'let 'em get hot' to 'must heatsink'. In my experience items that require a heatsink have a milled flat surface to mount to a sink, not a thin case that would only touch in places. Furthermore I didn't think fiberglass circuit board was famous for its heat conducting properties. No sign of any heat transfer compound either. So do I conclude they need a bit of cooling? I agree with you Pete and would really like to know what the makers say about all this! Best wishes, John. On 20 Dec 2011, at 16:22, Peter Bell wrote: 340mA seems really high - all the ones I've seen take about 90mA - and I would strongly recommend putting in on a heatsink, or at least bolting it directly to the chassis. In my experience, they don't actually malfunction when operated without one, but the housing gets very hot (and, presumably, the insides get hotter still) - after 24h running sitting on a foam mouse mat open to the air, the case hit about 59c - I can't help thinking that isn't going to be good for the long-term health of the unit. Regards, Pete On Wed, Dec 21, 2011 at 12:03 AM, Chuck Forsberg WA7KGX N2469R c...@omen.com wrote: Mine requires the 5 volt supply at 340 ma. Are there nay manufacturer's instructions about mounting, ventilating, or heat sinking these units? My current thinking is to mount it on standoffs on the back of the chassis that houses my Thunderbolt. Perhaps I should place it where it can warm up Princess. (Notice the magnet on top of the oscillator.) On 12/20/2011 07:13 AM, Roy Phillips wrote: -- From: Rexr...@sonic.net Sent: Tuesday, December 20, 2011 1:10 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. regards Nigel GM8PZR Nigel I trust that you are aware that some models of the FE-5680A only require the 15 volt/1.7Amp. supply. In fact connecting a 5 volt supply to the units that are programmable can cause damage ! Roy ___ time-nuts mailing 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. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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 message.
Re: [time-nuts] Efratom FRK - no 10Mhz oscillator
Hi, Don It's been quite a while since I worked on a FRK, but from what I remember the only signals going to that oscillator board are power and the control voltage. It might be worth checking the control voltage to see if it's at a plausible value (nominal is 5V, spec range is 1V-16V, IIRC) - if you have a spare xtal around, just try connecting it to the pins on the PCB and see if it starts up. I'm not aware of the xtals being failure prone - I have seen one FRK with a bad one, but having seen the condition of the system it was removed from, that was clearly impact damage. Regards, Pete On Wed, Dec 21, 2011 at 1:29 AM, Don Lewis dlewis6...@austin.rr.com wrote: A little help, pls, from the more experienced. This is my first time into one of these .I have listened and learned from you' all for some time, though. It can be intimidating in this close-packed FRK. I am trying to bring up an Efratom FRK I have had for a while. The 10 MHz oscillator does not start upon power on. Any ideas where to look? I have done the following: * I have it opened-up and applied 24vDC and the current starts up initially at 1.45 amp and slowly goes down to ~.6- .8 amps. * Since I have no 10 MHz output, .so I looked at the oscillator board and nothing out from it. * The 17 volt dc supply-rail is good, and the VCO input signal to the varacter control-circuitry is constantly ramping up and down slowly between ~1volt and ~15 volts. * All the transistors in the oscillator circuit seem ok with a VOM, ..and when I purposely inject a 10Mhz signal into the collector of the 'oscillator' transistor (Q3), .I do get a clean 10Mhz out of the unit (of course it won't lock), .and I haven't even been into the rest of the unit. * I think the crystal is bad, .I took the cover off the crystal oven, it 'looks' ok, . and the crystal heater in the oven is heating and regulating. Any ideas? .does the 10 MHz crystal in these have a history of failing? Can I get a replacement crystal for it easily? How can I test this crystal for pass/fail? Thanks, .just my first test of the waters as a fledging time-nut. Don Lewis Austin, TX ___ time-nuts mailing 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] Efratom FRK - no 10Mhz oscillator
I have some M100s, which are similar, I think. A while back one of them wouldn't lock, although the oscillator didn't stop. I found a leaky high-K ceramic cap in the OCXO control loop. I don't have the correct schematics, so was just shotgunning stuff. I would suspect those parts and any tantalum caps in that section. I don't think they used any aluminum electrolytics in this mil-grade gear. VCOs can stall from inadvertently reversing the polarity on the varicap diode, causing it to forward bias. In some circuits this is possible, which turns the varicap from a high-Q capacitor into a load resistance on the oscillator. You may want to check the loop conditions (not in a lockup/reversed mode) and make sure the actual diode tuning signal is in the right range before blaming the crystal. If not, you can force it and see if the XO starts up. Ed ___ time-nuts mailing 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] Ebay FE-5680A Rb I see the price has gone up for these
I also got an FE5680A, what a deal. Thanks to earlier postings I had the correct pin out, info on the 1/16 hex key and the command set. It needs 5V on pin 4 to operate. After 24 hours mine ran 6 mHz low compared to my GPS-based 10 MHz. I opened the case by removing the 2 flat head screws near the connector and the 2 pan head screws in recesses in the center of the base plate. I noticed what looked like smoke residue from a blown part, as have others, but no sign of a bad part. The LPRO-101 has a flat surface and a thermal pad for heat transfer over the whole base. The FE-5680A injects heat into the base plate in the center and sinks it around the edges. Good magnetic shielding and thermal transfer may require using most of the 16 mounting holes. I found Termite 2.7 from CompuPhase worked to communicate with the FE-5680A in Windows. I set the COM port, 9600 baud, local echo, append nothing and hex view. I sent 0x2D040029 to get the offset. The 0x lets the program know the number is in hex. My offset was 0, same as others have mentioned. Possibly the FE-5680 was controlled externally to sync up the 1pps output to GPS using the set temporary offset command. I wonder if there's a status command, analogous to the lamp voltage test point on the LPRO-101. Bob -Original Message- From: Chuck Forsberg WA7KGX N2469R Sent: Monday, December 19, 2011 2:25 PM To: li...@lazygranch.com ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for these My 5680A arrived today. Mailman demanded a signature. This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] My Racal-Dana 1992
Ah. That seems right, Charles, going by the behavior. In that case, what and where is the reference for the heater servo? The ambient temperature? Not too wise a choice, but what else? So it may be that the temperature is the controlling element but it, too, is an open system? It can be open, too, just second order? This is a knotty one! Don Charles P. Steinmetz Don wrote: This is typical for an underdamped second order servo. The oscillation is the penalty for a shorter settling time. A critically damped system would not oscillate, but approach the final value smoothly in a slightly longer time. It may have been designed for a slight overshoot... Yes, I understand and I don't doubt that it is performing as designed. My point was that most crystal oscillator frequency adjustments (at least, the ones that I have seen) are open-loop (variable capacitor or pot to a varactor diode). Finding the fine frequency control apparently in a servo loop was a surprise. And it cannot be a PLL or FLL, because there is only the one reference -- the one you are adjusting. Since the startup dynamics are so similar to the fine frequency adjustment dynamics (not to mention that the oven loop is pretty much the only possible servo in the oscillator), the evidence appears strong that the fine frequency adjustment is an oven temperature adjustment. Unless there is something truly diabolical going on inside a 9462. 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. -- 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] Ebay FE-5680A Rb I see the price has gone up for these
Should get the 5 volts with the usual 3-legged fuse :-) ?? Don Rex FWIW. I just hapened on this power supply in an ad. You might find a fixed voltage one somewhere cheaper, but the price seemed ok, so here it is for consideration... http://www.mpja.com/email/12-13-11.asp?r=284759s=2 Still need the 5 V somehow, so not a complete solution for the 5680A. On 12/19/2011 3:06 PM, gandal...@aol.com wrote: In a message dated 19/12/2011 22:27:22 GMT Standard Time, c...@omen.com writes: This thing requires plenty of current to get started. My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts. Now to scrounge something a bit bigger. - The 15 volts to pin 1 starts off needing to supply around 1.7 Amps, eventually falling to somewhere between 700 and 800 mA. Pin 4 always draws around 85 to 90 mA from its 5 volt supply. 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. -- 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] My Racal-Dana 1992
If I still have it, I'll take a picture of the 1992 i salvaged the keyboard from. I was told it had 2 KW @ 700 MHz applied to it. They do not make very good dummy loads. -pete On Tue, Dec 20, 2011 at 11:31 AM, Don Latham d...@montana.com wrote: Ah. That seems right, Charles, going by the behavior. In that case, what and where is the reference for the heater servo? The ambient temperature? Not too wise a choice, but what else? So it may be that the temperature is the controlling element but it, too, is an open system? It can be open, too, just second order? This is a knotty one! Don Charles P. Steinmetz Don wrote: This is typical for an underdamped second order servo. The oscillation is the penalty for a shorter settling time. A critically damped system would not oscillate, but approach the final value smoothly in a slightly longer time. It may have been designed for a slight overshoot... Yes, I understand and I don't doubt that it is performing as designed. My point was that most crystal oscillator frequency adjustments (at least, the ones that I have seen) are open-loop (variable capacitor or pot to a varactor diode). Finding the fine frequency control apparently in a servo loop was a surprise. And it cannot be a PLL or FLL, because there is only the one reference -- the one you are adjusting. Since the startup dynamics are so similar to the fine frequency adjustment dynamics (not to mention that the oven loop is pretty much the only possible servo in the oscillator), the evidence appears strong that the fine frequency adjustment is an oven temperature adjustment. Unless there is something truly diabolical going on inside a 9462. 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. -- 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. ___ time-nuts mailing 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] Efratom FRK - no 10Mhz oscillator
10MHz crystals used in OCXO are designed for the temperature of the oven so it is not possible to find an off-the-shelf suitable crystal. Better find a crystal coming from an OCXO. On Tue, Dec 20, 2011 at 7:10 PM, Peter Bell bell.pe...@gmail.com wrote: Hi, Don It's been quite a while since I worked on a FRK, but from what I remember the only signals going to that oscillator board are power and the control voltage. It might be worth checking the control voltage to see if it's at a plausible value (nominal is 5V, spec range is 1V-16V, IIRC) - if you have a spare xtal around, just try connecting it to the pins on the PCB and see if it starts up. I'm not aware of the xtals being failure prone - I have seen one FRK with a bad one, but having seen the condition of the system it was removed from, that was clearly impact damage. Regards, Pete On Wed, Dec 21, 2011 at 1:29 AM, Don Lewis dlewis6...@austin.rr.com wrote: A little help, pls, from the more experienced. This is my first time into one of these .I have listened and learned from you' all for some time, though. It can be intimidating in this close-packed FRK. I am trying to bring up an Efratom FRK I have had for a while. The 10 MHz oscillator does not start upon power on. Any ideas where to look? I have done the following: * I have it opened-up and applied 24vDC and the current starts up initially at 1.45 amp and slowly goes down to ~.6- .8 amps. * Since I have no 10 MHz output, .so I looked at the oscillator board and nothing out from it. * The 17 volt dc supply-rail is good, and the VCO input signal to the varacter control-circuitry is constantly ramping up and down slowly between ~1volt and ~15 volts. * All the transistors in the oscillator circuit seem ok with a VOM, ..and when I purposely inject a 10Mhz signal into the collector of the 'oscillator' transistor (Q3), .I do get a clean 10Mhz out of the unit (of course it won't lock), .and I haven't even been into the rest of the unit. * I think the crystal is bad, .I took the cover off the crystal oven, it 'looks' ok, . and the crystal heater in the oven is heating and regulating. Any ideas? .does the 10 MHz crystal in these have a history of failing? Can I get a replacement crystal for it easily? How can I test this crystal for pass/fail? Thanks, .just my first test of the waters as a fledging time-nut. Don Lewis Austin, TX ___ time-nuts mailing 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] Efratom FRK - no 10Mhz oscillator
Thank you all for your help this afternoon. Good ideas. I better hope the crystal is good and just concentrate on the discrete. I'll continue to investigate. The oscillator won't oscillate on its on, but if I 'force' a 10MHz signal either on the collector of Q3 or even touch the crystal oven with the 10MHx signal, ...it will oscillate and amplify and deliver a signal. Must be a cap or perhaps the inductor in the 10MHz circuit. -Don -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Tuesday, December 20, 2011 3:01 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Efratom FRK - no 10Mhz oscillator 10MHz crystals used in OCXO are designed for the temperature of the oven so it is not possible to find an off-the-shelf suitable crystal. Better find a crystal coming from an OCXO. On Tue, Dec 20, 2011 at 7:10 PM, Peter Bell bell.pe...@gmail.com wrote: Hi, Don It's been quite a while since I worked on a FRK, but from what I remember the only signals going to that oscillator board are power and the control voltage. It might be worth checking the control voltage to see if it's at a plausible value (nominal is 5V, spec range is 1V-16V, IIRC) - if you have a spare xtal around, just try connecting it to the pins on the PCB and see if it starts up. I'm not aware of the xtals being failure prone - I have seen one FRK with a bad one, but having seen the condition of the system it was removed from, that was clearly impact damage. Regards, Pete On Wed, Dec 21, 2011 at 1:29 AM, Don Lewis dlewis6...@austin.rr.com wrote: A little help, pls, from the more experienced. This is my first time into one of these .I have listened and learned from you' all for some time, though. It can be intimidating in this close-packed FRK. I am trying to bring up an Efratom FRK I have had for a while. The 10 MHz oscillator does not start upon power on. Any ideas where to look? I have done the following: * I have it opened-up and applied 24vDC and the current starts up initially at 1.45 amp and slowly goes down to ~.6- .8 amps. * Since I have no 10 MHz output, .so I looked at the oscillator board and nothing out from it. * The 17 volt dc supply-rail is good, and the VCO input signal to the varacter control-circuitry is constantly ramping up and down slowly between ~1volt and ~15 volts. * All the transistors in the oscillator circuit seem ok with a VOM, ..and when I purposely inject a 10Mhz signal into the collector of the 'oscillator' transistor (Q3), .I do get a clean 10Mhz out of the unit (of course it won't lock), .and I haven't even been into the rest of the unit. * I think the crystal is bad, .I took the cover off the crystal oven, it 'looks' ok, . and the crystal heater in the oven is heating and regulating. Any ideas? .does the 10 MHz crystal in these have a history of failing? Can I get a replacement crystal for it easily? How can I test this crystal for pass/fail? Thanks, .just my first test of the waters as a fledging time-nut. Don Lewis Austin, TX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] My Racal-Dana 1992
Don wrote: In that case, what and where is the reference for the heater servo? It will be a voltage or current, suitably regulated and conditioned. The temperature sensor's signal will be (or will be converted to) a voltage or current that is compared to the reference voltage or current. Zeroing and scaling are done in the servo amplifier and/or the reference conditioning. In principle, you could do the same thing with frequency -- feed a voltage-controlled oscillator into a frequency-to-voltage converter and servo the FVC output to a reference voltage. But the physical signal we can generate directly most accurately is frequency (using quartz crystals or atomic resonators). Think about it -- most time nuts have one or more frequency standards that are not only stable, but accurate to E-9 or better (sometimes quite a lot better), and can scale that accuracy to a wide range of frequencies. The volt nut, on the other hand, struggles to maintain repeatability -- much less accuracy -- to parts in E-7 at just one voltage. 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.
