[time-nuts] HP 3586B Selective Level Meter
Got one of these massive (by today's standards) beasts the other day. It has the option 003. Quite the light show when it powers up. I have its external reference daisy chained with a radio and two other instruments sucking 10 MHz from my Thunderbolt. I have not decided what to do with the ATT front panel input. Should I get a BNC adapter for it? Or replace it with a BNC connector? -- 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] Trimble Mini-T end of life
Hello everyone, please send suggestions for the following new product we are working on: Trimble recently announced that the Mini-T is end of life, and is giving a last time buy of August 1st 2012. It does not seem that Trimble plans to offer a replacement unit. The Mini-t enjoyed a relatively short lifetime, and it seems Trimble has left it's customers hanging in the air, as when it discontinued the Thunderbolt some time ago. Jackson Labs Tech is in the process of designing a replacement unit for the Mini-T that customers will be able to use as a direct replacement so that they don't have to order more units than they need and don't have to cancel running projects, but this unit will have much higher performance and significantly more features and options to chose from. Availability of evaluation units is early next month, and it will not be discontinued as long as there is demand. There is still a window of opportunity to suggest added useful features, so please do send your suggestions to me as to what you would like to see in a perfect Mini-T replacement unit. We will consider all reasonable suggestions and requests. Thanks much in advance, Said ___ 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] Trimble Mini-T end of life
Hi: I would like the capability to run external high quality quartz oscillators like a HP106 HP105, HP104R, HP103, HP107BR Etc, and Rubidium Oscillators like the PRS-10 and FE products. Also It would be nice if Lady Heather would also run it in order to reduce another learning curve. I would be very interested in this product. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of saidj...@aol.com Sent: Thursday, July 19, 2012 12:16 AM To: time-nuts@febo.com Subject: [time-nuts] Trimble Mini-T end of life Hello everyone, please send suggestions for the following new product we are working on: Trimble recently announced that the Mini-T is end of life, and is giving a last time buy of August 1st 2012. It does not seem that Trimble plans to offer a replacement unit. The Mini-t enjoyed a relatively short lifetime, and it seems Trimble has left it's customers hanging in the air, as when it discontinued the Thunderbolt some time ago. Jackson Labs Tech is in the process of designing a replacement unit for the Mini-T that customers will be able to use as a direct replacement so that they don't have to order more units than they need and don't have to cancel running projects, but this unit will have much higher performance and significantly more features and options to chose from. Availability of evaluation units is early next month, and it will not be discontinued as long as there is demand. There is still a window of opportunity to suggest added useful features, so please do send your suggestions to me as to what you would like to see in a perfect Mini-T replacement unit. We will consider all reasonable suggestions and requests. Thanks much in advance, Said ___ 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] Trimble Mini-T end of life
Le 19/07/2012 09:15, saidj...@aol.com a écrit : Mini-T is end of life How about onboard DDS with sine/square choice( and own SMA out if space avalable)? Also programmable PPS offsets if not already available. -- Les chiens aboient, et la caravane passe. ___ 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] HP 3586B Selective Level Meter
I think that valuable test equipment must stay original and unmodified: get an adapter. Maybe you can find a cable with the proper connector and put a BNC on the other end... On Thu, Jul 19, 2012 at 8:22 AM, Chuck Forsberg WA7KGX N2469R c...@omen.comwrote: Got one of these massive (by today's standards) beasts the other day. It has the option 003. Quite the light show when it powers up. I have its external reference daisy chained with a radio and two other instruments sucking 10 MHz from my Thunderbolt. I have not decided what to do with the ATT front panel input. Should I get a BNC adapter for it? Or replace it with a BNC connector? -- 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] HP 3586B Selective Level Meter
I have one of these as well, interesting instrument. I used it with an adapter for a while then one day got tired of that and found a nice BNC from my bin which fit beautifully and got rid of the weird connector. It's much nicer this way. At these frequencies the connector type is based on usability convenience and for me the BNC was just a lot easier to deal with. Perhaps the day that wiggling the adapter made the readings move a few tenths of a dB convinced me. Peter On 7/19/2012 2:22 AM, Chuck Forsberg WA7KGX N2469R wrote: Got one of these massive (by today's standards) beasts the other day. It has the option 003. Quite the light show when it powers up. I have its external reference daisy chained with a radio and two other instruments sucking 10 MHz from my Thunderbolt. I have not decided what to do with the ATT front panel input. Should I get a BNC adapter for it? Or replace it with a BNC connector? ___ 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] HP 3586B Selective Level Meter
Purchase the Canare BCJ-VWP adapter from Martertech or other suppliers. Bill Riches, WA2DVU Cape May, NJ -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Forsberg WA7KGX N2469R Sent: Thursday, July 19, 2012 2:22 AM To: time-nuts Subject: [time-nuts] HP 3586B Selective Level Meter Got one of these massive (by today's standards) beasts the other day. It has the option 003. Quite the light show when it powers up. I have its external reference daisy chained with a radio and two other instruments sucking 10 MHz from my Thunderbolt. I have not decided what to do with the ATT front panel input. Should I get a BNC adapter for it? Or replace it with a BNC connector? -- 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] HP 3586B Selective Level Meter
Hi Chuck I have number of these Make great precision receivers Use it on the Thunderbolt, and turn on the 0.1 Hz counter to see if WWF is on freq. HI More interesting game is to look at foreign broadcast carriers to see who are running professional plants locked to a standard, and who are the cheap outfits that somewhere the right freq. 73 Les Lester B Veenstra MØYCM K1YCM W8YCM les...@veenstras.com US Postal Address: 5 Shrine Club Drive HC84 Box 89C Keyser WV 26726 GPS: 39.33675 N 78.9823527 W Telephones: Home: +1-304-289-6057 Corrected US cell +1-304-790-9192 Changed to permanent number Guam Cell: +1-671-929-8141 Jamaica: +1-876-352-7504 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Forsberg WA7KGX N2469R Sent: 19 July 2012 02:22 To: time-nuts Subject: [time-nuts] HP 3586B Selective Level Meter Got one of these massive (by today's standards) beasts the other day. It has the option 003. Quite the light show when it powers up. I have its external reference daisy chained with a radio and two other instruments sucking 10 MHz from my Thunderbolt. I have not decided what to do with the ATT front panel input. Should I get a BNC adapter for it? Or replace it with a BNC connector? -- 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] HP 3586B Selective Level Meter
If their AGC was better they would also make reasonable high sensitivity receivers. You are right; it is amazing to see how far off some broadcast carriers really are. Peter On 07/19/12, Lester Veenstrales...@veenstras.com wrote: Hi Chuck I have number of these Make great precision receivers Use it on the Thunderbolt, and turn on the 0.1 Hz counter to see if WWF is on freq. HI More interesting game is to look at foreign broadcast carriers to see who are running professional plants locked to a standard, and who are the cheap outfits that somewhere the right freq. 73 Les Lester B Veenstra MA~YCM K1YCM W8YCM [1]les...@veenstras.com US Postal Address: 5 Shrine Club Drive HC84 Box 89C Keyser WV 26726 GPS: 39.33675 N 78.9823527 W Telephones: Home: +1-304-289-6057 Corrected US cell +1-304-790-9192 Changed to permanent number Guam Cell: +1-671-929-8141 Jamaica: +1-876-352-7504 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. -Original Message- From: [2]time-nuts-boun...@febo.com [[3]mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Forsberg WA7KGX N2469R Sent: 19 July 2012 02:22 To: time-nuts Subject: [time-nuts] HP 3586B Selective Level Meter Got one of these massive (by today's standards) beasts the other day. It has the option 003. Quite the light show when it powers up. I have its external reference daisy chained with a radio and two other instruments sucking 10 MHz from my Thunderbolt. I have not decided what to do with the ATT front panel input. Should I get a BNC adapter for it? Or replace it with a BNC connector? -- Chuck Forsberg WA7KGX N2469R [4]c...@omen.com [5]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 -- [6]time-nuts@febo.com To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- [8]time-nuts@febo.com To unsubscribe, go to [9]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:les...@veenstras.com 2. mailto:time-nuts-boun...@febo.com 3. mailto:time-nuts-boun...@febo.com 4. mailto:c...@omen.com 5. http://www.omen.com/ 6. mailto:time-nuts@febo.com 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 8. mailto:time-nuts@febo.com 9. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ 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] Timing Health Monitoring
Richard, This paper is fascinating to me. I finally understand how the TMDE/Metrology lab to which I continually sent my measurement equipment for calibration was so important. Looking back, I recall something that looked exactly like an FMS rack shown in the paper! It was accompanied by a make-shift cubicle with walls of HP and Marconi gear in various states... and a sweet, aged, bearded geek with trifocals... It's telling, I think, that the first FMS was built on an Apple II. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us On Jul 18, 2012, at 7:00 PM, Richard H McCorkle wrote: Chris, If you have multiple standards to monitor (or may have in the future) you might consider building a small version of the NIST FMAS board described in http://tf.nist.gov/general/pdf/1950.pdf to keep track of them. Richard What advice does anyone have on building/finding cheap [visual?] comparison devices to display or detect a timing [lesajo?] from my 10MHz sine wave ports? Further, what timing/health metrics could/should I be aware of and/or looking for? I do not want to spend good money on another oscillicope if I can help it, but I do want to see, or at least be remotely aware of clock slips/walks and other anomalies. I am thinking about building an embedded system to automate monitoring, configuration, and alerts... perhaps using an Arduino. -CH ___ 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] Zero-Crossing Detector Design?
Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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] Trimble Mini-T end of life
How about a couple of buffers for counting external (opto-isolated) pulses or sines? A 1 to 5Vpp range might do it, maybe with a sensitivity north of 100MHz? -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us On Jul 19, 2012, at 12:15 AM, saidj...@aol.com wrote: Hello everyone, please send suggestions for the following new product we are working on: Trimble recently announced that the Mini-T is end of life, and is giving a last time buy of August 1st 2012. It does not seem that Trimble plans to offer a replacement unit. The Mini-t enjoyed a relatively short lifetime, and it seems Trimble has left it's customers hanging in the air, as when it discontinued the Thunderbolt some time ago. Jackson Labs Tech is in the process of designing a replacement unit for the Mini-T that customers will be able to use as a direct replacement so that they don't have to order more units than they need and don't have to cancel running projects, but this unit will have much higher performance and significantly more features and options to chose from. Availability of evaluation units is early next month, and it will not be discontinued as long as there is demand. There is still a window of opportunity to suggest added useful features, so please do send your suggestions to me as to what you would like to see in a perfect Mini-T replacement unit. We will consider all reasonable suggestions and requests. Thanks much in advance, Said ___ 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] WWVB a different approach to d-bpsk-r (cheating)
As long as you don't have sunset or sunrise between you and the transmitter, WWVB is reasonably stable. At night you will get more signal, but also can have some skywave stuff in the mix. One man's noise is another man's signal. The NIST coverage maps vary widely from night to day. I assume their night maps depend upon skywave. So depending upon where you live, the some skywave stuff may be very important. Maybe fancy (rather than low cost) receivers work without (in spite of) the skywave. -- These are my opinions. 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.
Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
On 7/19/2012 1:30 PM, Hal Murray wrote: As long as you don't have sunset or sunrise between you and the transmitter, WWVB is reasonably stable. At night you will get more signal, but also can have some skywave stuff in the mix. One man's noise is another man's signal. The NIST coverage maps vary widely from night to day. I assume their night maps depend upon skywave. So depending upon where you live, the some skywave stuff may be very important. Maybe fancy (rather than low cost) receivers work without (in spite of) the skywave. Hal Life is never easy. I think wwvb should just connect a direct fibre to anyone that wants it. I could get rid of the RBs and CS etc. Oh well. Yes indeed I see the effects you are speaking of. So strangely during the day the gps tic lines up with a rising edge of the cycle. Kind of amazing actually as I am in Boston. At sunset and sunrise I do see at least a 7-10us shift and its variable. But I don't think any of this matters a lot. My logic is this wait for a gps tick or even a local tick Is the wwvb a plus cycle or minus. If minus flip to plus Can get all fancy then check a couple of cyles and make sure its plus or minus then flip. Also as diurnal shift occurs its usually slow enough that the system can keep flipping as needed to keep the plus cycle aligned to the gps tick. Lots of clever things can be done if the simple theory holds or is even reasonable. A subset of the approach is check if a + if not is it actually a minus or zero a fade. Do nothing if a fade. All to familiar here. So this is not at all hard to build program or test. Just have a few distractions at hand. Regards Paul WB8TSL ___ 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] Zero-Crossing Detector Design?
This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffman cq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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] Zero-Crossing Detector Design?
Thank you, Azelio! I don't suppose there's an impromptu FAQ page out there, is there? -CH On Jul 19, 2012, at 11:58, Azelio Boriani azelio.bori...@screen.it wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffman cq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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] Zero-Crossing Detector Design?
you can search time-nuts there has been a number of very good discussions on this. Sorry to say how you search is equally a good question. On Thu, Jul 19, 2012 at 3:19 PM, Chris Hoffman, KG6O cq.k...@gmail.comwrote: Thank you, Azelio! I don't suppose there's an impromptu FAQ page out there, is there? -CH On Jul 19, 2012, at 11:58, Azelio Boriani azelio.bori...@screen.it wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffman cq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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] Zero-Crossing Detector Design?
Yes, there are no FAQ but you can search the archive. I don't know how to search the archive because usually I start with google, adding time-nuts to narrow down the search. On Thu, Jul 19, 2012 at 9:23 PM, paul swed paulsw...@gmail.com wrote: you can search time-nuts there has been a number of very good discussions on this. Sorry to say how you search is equally a good question. On Thu, Jul 19, 2012 at 3:19 PM, Chris Hoffman, KG6O cq.k...@gmail.com wrote: Thank you, Azelio! I don't suppose there's an impromptu FAQ page out there, is there? -CH On Jul 19, 2012, at 11:58, Azelio Boriani azelio.bori...@screen.it wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffman cq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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. ___ 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] Timing Health Monitoring
On 07/19/2012 05:48 PM, Chris Hoffman wrote: Richard, This paper is fascinating to me. I finally understand how the TMDE/Metrology lab to which I continually sent my measurement equipment for calibration was so important. Looking back, I recall something that looked exactly like an FMS rack shown in the paper! It was accompanied by a make-shift cubicle with walls of HP and Marconi gear in various states... and a sweet, aged, bearded geek with trifocals... It's telling, I think, that the first FMS was built on an Apple II. The NIST time-scale algorithm was run on a PDP-8 with 5kWord memory. It used to run on a pair of AT machines, but they have upgraded to a pair of 386s now. Every 12 min they will execute for 40 s and then go back to idle waiting. Processing-wise, there is no need to get more modern machines. Can't recall seeing that paper, so thanks for the reference. Had a nice chat with one of the techs dealing with those services. Very nice folks! Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Zero-Crossing Detector Design?
The problem of optimal zero crossing detector design was essentially solved by Oliver Collins in the 1990's. Essentially a series of cascaded limiter stages with appropriate gain and bandwidth distribution are used. With a 10MHz 1V rms signal only 2-3 stages suffices. However unless you need fs jitter less complex zero crossing detectors should suffice. 1) a comparator (or line receiver) based design should achieve sub 10ps jitter. 2) AC coupling to the input of a CMOS (AC04, AHC04 LVC04) should achieve a jitter of 1ps or less 3) A simple differential pair with AC coupled emitters (reduces asymmetry due to component tolerances ) is capable of sub ps jitter. There is a spreadsheet to assist design of Collins style zero crossing detectors at: http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html http://www.ko4bb.com/%7Ebruce/ZeroCrossingDetectors.html Bruce paul swed wrote: you can search time-nuts there has been a number of very good discussions on this. Sorry to say how you search is equally a good question. On Thu, Jul 19, 2012 at 3:19 PM, Chris Hoffman, KG6Ocq.k...@gmail.comwrote: Thank you, Azelio! I don't suppose there's an impromptu FAQ page out there, is there? -CH On Jul 19, 2012, at 11:58, Azelio Borianiazelio.bori...@screen.it wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffmancq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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. ___ 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] HP 3586B Selective Level Meter
The problem with them as a general HF receiver is the input is too sensitive, so that when presented with .001 t0 32 MHz it overloads and you get noise floor dominated by intermods. Put a bandpass in front. And all should be good. Lester B Veenstra MØYCM K1YCM W8YCM les...@veenstras.com US Postal Address: 5 Shrine Club Drive HC84 Box 89C Keyser WV 26726 GPS: 39.33675 N 78.9823527 W Telephones: Home: +1-304-289-6057 Corrected US cell +1-304-790-9192 Changed to permanent number Guam Cell: +1-671-929-8141 Jamaica: +1-876-352-7504 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Gottlieb Sent: 19 July 2012 09:22 To: time-nuts@febo.com Subject: Re: [time-nuts] HP 3586B Selective Level Meter If their AGC was better they would also make reasonable high sensitivity receivers. You are right; it is amazing to see how far off some broadcast carriers really are. Peter On 07/19/12, Lester Veenstrales...@veenstras.com wrote: Hi Chuck I have number of these Make great precision receivers Use it on the Thunderbolt, and turn on the 0.1 Hz counter to see if WWF is on freq. HI More interesting game is to look at foreign broadcast carriers to see who are running professional plants locked to a standard, and who are the cheap outfits that somewhere the right freq. 73 Les Lester B Veenstra MA~YCM K1YCM W8YCM [1]les...@veenstras.com US Postal Address: 5 Shrine Club Drive HC84 Box 89C Keyser WV 26726 GPS: 39.33675 N 78.9823527 W Telephones: Home: +1-304-289-6057 Corrected US cell +1-304-790-9192 Changed to permanent number Guam Cell: +1-671-929-8141 Jamaica: +1-876-352-7504 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. -Original Message- From: [2]time-nuts-boun...@febo.com [[3]mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Forsberg WA7KGX N2469R Sent: 19 July 2012 02:22 To: time-nuts Subject: [time-nuts] HP 3586B Selective Level Meter Got one of these massive (by today's standards) beasts the other day. It has the option 003. Quite the light show when it powers up. I have its external reference daisy chained with a radio and two other instruments sucking 10 MHz from my Thunderbolt. I have not decided what to do with the ATT front panel input. Should I get a BNC adapter for it? Or replace it with a BNC connector? -- Chuck Forsberg WA7KGX N2469R [4]c...@omen.com [5]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 -- [6]time-nuts@febo.com To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- [8]time-nuts@febo.com To unsubscribe, go to [9]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:les...@veenstras.com 2. mailto:time-nuts-boun...@febo.com 3. mailto:time-nuts-boun...@febo.com 4. mailto:c...@omen.com 5. http://www.omen.com/ 6. mailto:time-nuts@febo.com 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 8. mailto:time-nuts@febo.com 9. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ 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] Zero-Crossing Detector Design?
Actually, I being new to the list, I do not feel I the correct verbiage. That said, I will do better on keeping the noise down. Again, my thanks. -CH On Jul 19, 2012, at 12:23, paul swed paulsw...@gmail.com wrote: you can search time-nuts there has been a number of very good discussions on this. Sorry to say how you search is equally a good question. On Thu, Jul 19, 2012 at 3:19 PM, Chris Hoffman, KG6O cq.k...@gmail.comwrote: Thank you, Azelio! I don't suppose there's an impromptu FAQ page out there, is there? -CH On Jul 19, 2012, at 11:58, Azelio Boriani azelio.bori...@screen.it wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffman cq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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. ___ 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] Zero-Crossing Detector Design?
Thank you, Bruce!!! That is exactly the information I was looking for. I sincerely appreciate the help. -CH On Jul 19, 2012, at 12:47, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: The problem of optimal zero crossing detector design was essentially solved by Oliver Collins in the 1990's. Essentially a series of cascaded limiter stages with appropriate gain and bandwidth distribution are used. With a 10MHz 1V rms signal only 2-3 stages suffices. However unless you need fs jitter less complex zero crossing detectors should suffice. 1) a comparator (or line receiver) based design should achieve sub 10ps jitter. 2) AC coupling to the input of a CMOS (AC04, AHC04 LVC04) should achieve a jitter of 1ps or less 3) A simple differential pair with AC coupled emitters (reduces asymmetry due to component tolerances ) is capable of sub ps jitter. There is a spreadsheet to assist design of Collins style zero crossing detectors at: http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html http://www.ko4bb.com/%7Ebruce/ZeroCrossingDetectors.html Bruce paul swed wrote: you can search time-nuts there has been a number of very good discussions on this. Sorry to say how you search is equally a good question. On Thu, Jul 19, 2012 at 3:19 PM, Chris Hoffman, KG6Ocq.k...@gmail.comwrote: Thank you, Azelio! I don't suppose there's an impromptu FAQ page out there, is there? -CH On Jul 19, 2012, at 11:58, Azelio Borianiazelio.bori...@screen.it wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffmancq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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. ___ 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] Trimble Mini-T end of life
Hi Said, I know everyone is going to ask for the kitchen sink to be thrown in. BUT, how about just making a replacement that does exactly the same job with no added thrills ? That way your spending the least amount to produce a product and keeps the cost down to the customer which may cause them to want to keep designing with that particular product. just saying BillWB6BNQ saidj...@aol.com wrote: Hello everyone, please send suggestions for the following new product we are working on: Trimble recently announced that the Mini-T is end of life, and is giving a last time buy of August 1st 2012. It does not seem that Trimble plans to offer a replacement unit. The Mini-t enjoyed a relatively short lifetime, and it seems Trimble has left it's customers hanging in the air, as when it discontinued the Thunderbolt some time ago. Jackson Labs Tech is in the process of designing a replacement unit for the Mini-T that customers will be able to use as a direct replacement so that they don't have to order more units than they need and don't have to cancel running projects, but this unit will have much higher performance and significantly more features and options to chose from. Availability of evaluation units is early next month, and it will not be discontinued as long as there is demand. There is still a window of opportunity to suggest added useful features, so please do send your suggestions to me as to what you would like to see in a perfect Mini-T replacement unit. We will consider all reasonable suggestions and requests. Thanks much in advance, Said ___ 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] Timing Health Monitoring
Ah! The very height of elegance in a good design [imho] : no upgrade needed. -CH On Jul 19, 2012, at 12:40, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 07/19/2012 05:48 PM, Chris Hoffman wrote: Richard, This paper is fascinating to me. I finally understand how the TMDE/Metrology lab to which I continually sent my measurement equipment for calibration was so important. Looking back, I recall something that looked exactly like an FMS rack shown in the paper! It was accompanied by a make-shift cubicle with walls of HP and Marconi gear in various states... and a sweet, aged, bearded geek with trifocals... It's telling, I think, that the first FMS was built on an Apple II. The NIST time-scale algorithm was run on a PDP-8 with 5kWord memory. It used to run on a pair of AT machines, but they have upgraded to a pair of 386s now. Every 12 min they will execute for 40 s and then go back to idle waiting. Processing-wise, there is no need to get more modern machines. Can't recall seeing that paper, so thanks for the reference. Had a nice chat with one of the techs dealing with those services. Very nice folks! Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts 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] Orbital time-delayed angular momentum phasing....???!!
What does that do to the focussing properties of the dish? Didier KO4BB Michael Baker mp...@clanbaker.org wrote: Timenutters-- Along the lines of splitting time into small increments, there is an interesting article in the May 2012 issue of the IEEE Spectrum Journal. It describes experiments with what I am calling cork-screw time-shift phasing modulation or orbital time-delayed angular momentum phasing for lack of a better description of the process. This is not the same as circular-polarization of a radiated signal. Visualize a 4-ft dia parabolic reflector which has been cut (sliced) in a straight line from any arbitrary point on its outer edge to its center.Then, at the outer lip of the reflector surface, pull one side of the cut about a foot forward of the other side of the cut. The separation is greatest at the edge of the dish, gradually becoming less and less as the cut approaches the center of the dish. The concept is that RF energy from the feed progressively strikes different areas of the dish slightly ahead (time-wise) from RF energy that strikes other parts of the dish. Because the surface of the dish resembles a cork-screw the signal from the dish has elements that are time-delayed with respect to other parts. Accordingly, data elements can be incorporated into the signal which have sightly different time-delay angular momentum properties. Again, the folks working on this insist that this is not the same as circular polarity of the radiated signal such as is obtained with a helix antenna. At the receive end, the process is reversed, producing a signal which when demodulated can contain extra levels of data modulation superimposed on it. The article points out that there are skeptics of the process who say that this same modulation procedure can be done with other methods although the modulation and demodulation process would be much more complex. The orbital angular momentum of photons in the optical realm has been extensively studied, although applying these principles to RF is something new. Mike Baker -- ___ 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 Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] Zero-Crossing Detector Design?
On the Bruce page there is a table with increasing stage amplification from low-level to the output. If this is the optimum for low jitter how does it connect to the well-known rf design philosophy to have the highest amplification at the first stage, not the last stage, to have maximum S/N ? Any idea? - Henry Chris Hoffman, KG6O schrieb: Thank you, Bruce!!! That is exactly the information I was looking for. I sincerely appreciate the help. -CH On Jul 19, 2012, at 12:47, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: The problem of optimal zero crossing detector design was essentially solved by Oliver Collins in the 1990's. Essentially a series of cascaded limiter stages with appropriate gain and bandwidth distribution are used. With a 10MHz 1V rms signal only 2-3 stages suffices. However unless you need fs jitter less complex zero crossing detectors should suffice. 1) a comparator (or line receiver) based design should achieve sub 10ps jitter. 2) AC coupling to the input of a CMOS (AC04, AHC04 LVC04) should achieve a jitter of 1ps or less 3) A simple differential pair with AC coupled emitters (reduces asymmetry due to component tolerances ) is capable of sub ps jitter. There is a spreadsheet to assist design of Collins style zero crossing detectors at: http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html http://www.ko4bb.com/%7Ebruce/ZeroCrossingDetectors.html ___ 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] Zero-Crossing Detector Design?
Hi The numbers change rather dramatically if you are looking at the 1 to 10 Hz sine wave out of a beat note system… Bob On Jul 19, 2012, at 3:47 PM, Bruce Griffiths wrote: The problem of optimal zero crossing detector design was essentially solved by Oliver Collins in the 1990's. Essentially a series of cascaded limiter stages with appropriate gain and bandwidth distribution are used. With a 10MHz 1V rms signal only 2-3 stages suffices. However unless you need fs jitter less complex zero crossing detectors should suffice. 1) a comparator (or line receiver) based design should achieve sub 10ps jitter. 2) AC coupling to the input of a CMOS (AC04, AHC04 LVC04) should achieve a jitter of 1ps or less 3) A simple differential pair with AC coupled emitters (reduces asymmetry due to component tolerances ) is capable of sub ps jitter. There is a spreadsheet to assist design of Collins style zero crossing detectors at: http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html http://www.ko4bb.com/%7Ebruce/ZeroCrossingDetectors.html Bruce paul swed wrote: you can search time-nuts there has been a number of very good discussions on this. Sorry to say how you search is equally a good question. On Thu, Jul 19, 2012 at 3:19 PM, Chris Hoffman, KG6Ocq.k...@gmail.comwrote: Thank you, Azelio! I don't suppose there's an impromptu FAQ page out there, is there? -CH On Jul 19, 2012, at 11:58, Azelio Borianiazelio.bori...@screen.it wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. On Thu, Jul 19, 2012 at 6:03 PM, Chris Hoffmancq.k...@gmail.com wrote: Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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. ___ 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] Zero-Crossing Detector Design?
On 07/19/2012 11:53 PM, ehydra wrote: On the Bruce page there is a table with increasing stage amplification from low-level to the output. If this is the optimum for low jitter how does it connect to the well-known rf design philosophy to have the highest amplification at the first stage, not the last stage, to have maximum S/N ? Any idea? You balance noise bandwidth with slew-rate gain. Normally you just look at the noise of the amplifiers and comes up with the traditional gain formula. Here you only want the first amplifier to have the bandwidth that supports the slew-rate it will have, in the same way the next amplifier's bandwidth and gain is set to optimum. The goal becomes to achieve optimum slew-rate gain with least added noise. The formulas in the article is derived for same amplifier noise, where as Bruce generalized them for the case where the amplifier noises may be different. So, different design goals makes for different solutions. Makes sense or should I go into more detail? Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Mini-T end of life
Hi guys, thanks so much for all the great suggestions on how to make this product better! Yes, cost targets are a very important goal here, and we are looking into adding options that make sense for most customers and don't add excessive cost or delay to the schedule. We definitely will improve the performance of the unit over the original Mini-T though, because we feel that the Mini-T had sub-par performance on many fronts, and don't want to make the same mistakes. Some of the improvement items we have already decided upon are: * 50 channels GPS with WAAS/EGNOS/MSAS and Position-Hold mode with automatic initialization of the Auto-Survey process by default. Alternatively, the unit can be put into mobile mode, with Auto-Kalman filter optimization depending on vehicle velocity. -160dBm GPS tracking capability * A secondary 10MHz output (SMA or SMB connector, only the connector needs to be stuffed onto the PCB) to have access to the +13dBm output signal * Internal +3.3V antenna supply, that is automatically over-driven by the externally applied antenna supply * USB connector for command/control, RS-232 option, and TTL serial port for legacy compatibility * RoHs 6/6 for compatibility, and RoHs 5/6 option for much longer life and better MTBF than Mini-T * more than 3x better thermal stability, and at the same time more than double the temperature range (+/-5ppb over -40C to +85C versus +/-10ppb from only 0C to +60C) standard, and DOCXO option for even higher thermal stability performance and low-g sensitivity/ruggedized crystal options. * Better phase noise * Status LED's on board * TTL lock/ALARM indicator * External 1PPS input option on unused pin 1 of the main connector * Fully field-upgradable firmware, no FPGA programmer needed * Support for NMEA and SCPI commands * 3-axis accelerometer built-in * lower height: 0.47 inches OCXO height versus 0.75 inches * Much better ADEV performance * Factory-testing for crystal-jumps on every unit We also had several folks ask for alternative frequency outputs, and are currently investigating if we could use the secondary 10MHz connector to add another VCXO to generate any output frequency from 10MHz to 120+MHz such as is done on our ULN-1100 boards. This would add some cost though, and may just end up in a secondary version of the board so that customers who don't need it won't have to pay for it.. The most important item to get feedback on is the TSIP port, we cannot implement the entire TSIP command set as this is quite complex, most customers probably only use a handful of actual commands, and we believe the SCPI/NMEA command/control/status interface is much superior over the proprietary binary TSIP port. We are however open to implement a couple of useful and common TSIP outputs, and would greatly appreciate feedback and suggestions on this, for example a minimum set to make Lady Heather work..? Thanks, Said In a message dated 7/19/2012 13:41:07 Pacific Daylight Time, wb6...@cox.net writes: Hi Said, I know everyone is going to ask for the kitchen sink to be thrown in. BUT, how about just making a replacement that does exactly the same job with no added thrills ? That way your spending the least amount to produce a product and keeps the cost down to the customer which may cause them to want to keep designing with that particular product. just saying BillWB6BNQ ___ 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] Zero-Crossing Detector Design?
Are you speaking of slew rate limiting in the strict sense of the word, that is a current starved input stage due to the presence of a compensation cap? Or are you using the term slew more vaguely. -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Fri, 20 Jul 2012 00:15:58 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Zero-Crossing Detector Design? On 07/19/2012 11:53 PM, ehydra wrote: On the Bruce page there is a table with increasing stage amplification from low-level to the output. If this is the optimum for low jitter how does it connect to the well-known rf design philosophy to have the highest amplification at the first stage, not the last stage, to have maximum S/N ? Any idea? You balance noise bandwidth with slew-rate gain. Normally you just look at the noise of the amplifiers and comes up with the traditional gain formula. Here you only want the first amplifier to have the bandwidth that supports the slew-rate it will have, in the same way the next amplifier's bandwidth and gain is set to optimum. The goal becomes to achieve optimum slew-rate gain with least added noise. The formulas in the article is derived for same amplifier noise, where as Bruce generalized them for the case where the amplifier noises may be different. So, different design goals makes for different solutions. Makes sense or should I go into more detail? Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts 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] Zero-Crossing Detector Design?
Are you speaking of slew rate limiting in the strict sense of the word, that is a current starved input stage due to the presence of a compensation cap? Or are you using the term slew more vaguely. -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Fri, 20 Jul 2012 00:15:58 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Zero-Crossing Detector Design? On 07/19/2012 11:53 PM, ehydra wrote: On the Bruce page there is a table with increasing stage amplification from low-level to the output. If this is the optimum for low jitter how does it connect to the well-known rf design philosophy to have the highest amplification at the first stage, not the last stage, to have maximum S/N ? Any idea? You balance noise bandwidth with slew-rate gain. Normally you just look at the noise of the amplifiers and comes up with the traditional gain formula. Here you only want the first amplifier to have the bandwidth that supports the slew-rate it will have, in the same way the next amplifier's bandwidth and gain is set to optimum. The goal becomes to achieve optimum slew-rate gain with least added noise. The formulas in the article is derived for same amplifier noise, where as Bruce generalized them for the case where the amplifier noises may be different. So, different design goals makes for different solutions. Makes sense or should I go into more detail? Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts 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] Zero-Crossing Detector Design?
A fast comparator seems like a good idea, and it is simple, however it is actually the last thing you want to use. High thermal sensitivity and high jitter. Rick On 7/19/2012 1:35 PM, Dan Kemppainen wrote: Or use a fast comparator such as an ADCMP600 series. Much lower delays, and faster rising/falling edges. FYI, I've had good luck with this at 30Mhz. You could transformer couple this one, or simply couple it through a cap. Dan On 7/19/2012 3:47 PM, time-nuts-requ...@febo.com wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. ___ 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] OT but thought I would ask
This group has a wide range of interests so I thought I might ask if anyone has a manual for a Ithaca 393 lock in amplifier. Will also try the yahoo groups Please reply offline. Regards Paul WB8TSL ___ 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] Zero-Crossing Detector Design?
On 07/20/2012 12:33 AM, li...@lazygranch.com wrote: Are you speaking of slew rate limiting in the strict sense of the word, that is a current starved input stage due to the presence of a compensation cap? Or are you using the term slew more vaguely. I am speaking neither. If you have a sine of a particular frequency and amplitude, then you have a known slew-rate, it peaks at 2*pi*f*A, where A is the amplitude of the sine. As you amplify this signal, the slew-rate will grow proportionally. Recall that the jitter of a trigger point is noise divided by slew-rate. This is why we want to increase the slew-rate to a maximum while adding minimal noise. Now, as the amplifiers has a gain, to increase the slew-rate by say 5 times, the bandwidth of the amplifier needs to be high enough to support this, but in order to minimize the added noise, we want to keep the bandwidth down. This may be best realized by also recalling that it is the wideband noise at the trigger points which this first-degree analysis depends on, and the RMS level. A 1 Hz amplifier bandwidth is nice, but it won't support a high slew-rate... In a two amp setup the later amp will have a higher bandwidth, but the noise added of the first amp will also be gained up, so a tigther bandwidth there will keep its contribution lower. You end up with having high benefit for low noise amps in the beginning, but as you gain slew-rate the amplifier slew-rate capability becomes more important over it's noise properties. It's being balanced by amplifier feedback terms for both gain and bandwidth. Also, diode limiters will maintain the output as clipped sine, so we can continue to gain the output for slopes. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Zero-Crossing Detector Design?
On 07/20/2012 12:57 AM, Richard (Rick) Karlquist wrote: A fast comparator seems like a good idea, and it is simple, however it is actually the last thing you want to use. High thermal sensitivity and high jitter. Once your signal has past by a comparator, you can't treat it to remove the noise-induced jitter. As you gain the signal, the slew-rates can be made steeper and steeper prior to the comparator. The benefit of a comparator is that if you add hysteresis, it stays in that position and does not cause transition spikes, which can cause false extra triggers, with resulting state-polution. You can see this on some counters when you trigger them on a slope with bad slew-rate... and the frequency goes unstably up. This is when the experienced trims the trigger point for lower jitter (better slew-rate). Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Zero-Crossing Detector Design?
That was worth the elaboration. 2*pi*f*A is the classic design criteria used to insure your amplifier has sufficient slew rate for the task, where I am using slew in the strict sense of the word. Generally we use dv/dt when referring to the signal and slew when referring to the amplifier. Hey, some people say alligator clips and some say crocodile clips. (Yeah, I know there is a difference.) ___ 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] Zero-Crossing Detector Design?
On 07/20/2012 01:19 AM, li...@lazygranch.com wrote: That was worth the elaboration. 2*pi*f*A is the classic design criteria used to insure your amplifier has sufficient slew rate for the task, where I am using slew in the strict sense of the word. Generally we use dv/dt when referring to the signal and slew when referring to the amplifier. Hey, some people say alligator clips and some say crocodile clips. (Yeah, I know there is a difference.) In a DMTD setup, the amplifiers will operate very closely to the signal properties, so in that case the distinction becomes almost academic. Notice how I say that bandwidth (rather than slew) and gain is being controlled and calculated, which implies the slew-rate of the outgoing signal. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Zero-Crossing Detector Design?
Chris, The simplest zero crossing detector would be to feed your 1 volt, 10 mHz from the XL-DC into the input of an IC with schmidt trigger inputs. You would need to provide a series coupling cap and probably some DC bias from a pot to adjust symmetry of the output. I would also think that if you ran the four or six inverters of a schmidt trigger inverter chip in series that you would get a pretty good square wave out the end. I have an XL-DC with four 10 mHz sine outputs but have not had the need yet for a square wave. For that matter, it may be posible to find a 10 mHz square wave somewhere inside the box before it is converted to a sine wave that could be used for your application. Al Subject: [time-nuts] Zero-Crossing Detector Design? Can anyone suggest a good reference design for a zero-crossing detector? I am trying to home an ADC sampler trigger to the 1VRMS (50ohm) 10MHz sin from my XL-DC... And now I'm thinking that I should just home the uC clock to it, as well. Essentially, I believe that I'm looking for an efficient, stable, and accurate sine-to-square converter... and I'll welcome any advice in this area. This may also be used in a 1KHz 5Vpp IRIG-B decoder... I don't feel like rectifying the signal, to be honest. I want to try to keep a smaller BOM, sense the waveform primarily, and crunch numbers inside the uC. -CH Chris Hoffman cq.k...@gmail.com http://ar.ctur.us ___ 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] Zero-Crossing Detector Design?
On 07/19/2012 07:36 PM, Al Wolfe wrote: Chris, The simplest zero crossing detector would be to feed your 1 volt, 10 mHz from the XL-DC into the input of an IC with schmidt trigger inputs. You would need to provide a series coupling cap and probably some DC bias from a pot to adjust symmetry of the output. I would also think that if you ran the four or six inverters of a schmidt trigger inverter chip in series that you would get a pretty good square wave out the end. One circuit I was recommended when I was looking for ideas uses a 1M resistor to feed the output of the inverter back to the input to self-bias, like this: http://partiallystapled.com/~gxti/circuits/2012/07/06-beanpole.png I'm also trying a discrete approach based on the TADD-2 / T2-mini: http://partiallystapled.com/~gxti/circuits/2012/07/06-tadpole.png The latter has definitely been used successfully in timing applications but the simplicity of the inverter approach is very appealing, so I'm giving both a test, along with some other miscellaneous GPSDO components, before proceeding with a full GPSDO. -- m. tharp ___ 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] Zero-Crossing Detector Design?
Michael wrote: One circuit I was recommended when I was looking for ideas uses a 1M resistor to feed the output of the inverter back to the input to self-bias That works OK, but you have to be careful. Without an input signal, there can be excessive quiescent current through the inverter (Vcc to ground) -- for which it was not designed. 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] Zero-Crossing Detector Design?
Hi I think I'd call that a limiter rather than a zero crossing detector, that is indeed a bit picky. I think you will have better luck with a fixed bias on the input to the first inverter rather than with the 1 meg feedback resistor. With the feedback resistor the inverter tends to self oscillate. The self biased stage tends to go to one or the other state when the input is removed. With either approach, you will get the best performance when the AC signal is almost over-driving the input. Bob On Jul 19, 2012, at 8:23 PM, Michael Tharp wrote: On 07/19/2012 07:36 PM, Al Wolfe wrote: Chris, The simplest zero crossing detector would be to feed your 1 volt, 10 mHz from the XL-DC into the input of an IC with schmidt trigger inputs. You would need to provide a series coupling cap and probably some DC bias from a pot to adjust symmetry of the output. I would also think that if you ran the four or six inverters of a schmidt trigger inverter chip in series that you would get a pretty good square wave out the end. One circuit I was recommended when I was looking for ideas uses a 1M resistor to feed the output of the inverter back to the input to self-bias, like this: http://partiallystapled.com/~gxti/circuits/2012/07/06-beanpole.png I'm also trying a discrete approach based on the TADD-2 / T2-mini: http://partiallystapled.com/~gxti/circuits/2012/07/06-tadpole.png The latter has definitely been used successfully in timing applications but the simplicity of the inverter approach is very appealing, so I'm giving both a test, along with some other miscellaneous GPSDO components, before proceeding with a full GPSDO. -- m. tharp ___ 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] Zero-Crossing Detector Design?
On Thu, Jul 19, 2012 at 3:57 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: A fast comparator seems like a good idea, and it is simple, however it is actually the last thing you want to use. High thermal sensitivity and high jitter. The comparator will work but you need some positive feedback to create hysteresis. The problem is the hysteresis cause the output square wave to be not quite 50% duty cycle. But maybe you don't care if the goal is to count cycles. or if you only look at (say) raising edges. Rick On 7/19/2012 1:35 PM, Dan Kemppainen wrote: Or use a fast comparator such as an ADCMP600 series. Much lower delays, and faster rising/falling edges. FYI, I've had good luck with this at 30Mhz. You could transformer couple this one, or simply couple it through a cap. Dan On 7/19/2012 3:47 PM, time-nuts-requ...@febo.com wrote: This is sort of a FAQ: the argument was already discussed here. One of the most interesting idea (in my opinion) is to use an RS485 line receiver like the ST3485, MAX483, ADM485. They are actually transceivers so they must be tied permanently in RX. Since they are differential you can also put a 1:1 (or a 1:4 to raise the level) transformer to isolate the input too. ___ 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. -- 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] Zero-Crossing Detector Design?
Chris Albertson wrote: The comparator will work but you need some positive feedback to create hysteresis. The problem is the hysteresis cause the output square wave to be not quite 50% duty cycle. But maybe you don't care if the goal is to count cycles. or if you only look at (say) raising edges. Hysteresis does nothing to eliminate jitter or temperature drift. 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] Trimble Mini-T end of life
Just wondering about the internal 3.3 volt antenna supply. A switchable 3.3 or 5 volt supply would be nice. Antennas such as the Symmetricom 58532A still want 5 volts. Also if possible a waas only hold over mode would be nice (sorry I don't know if this is feasible or not.) Sent from my iPad On 2012-07-19, at 3:33 PM, saidj...@aol.com wrote: Hi guys, thanks so much for all the great suggestions on how to make this product better! Yes, cost targets are a very important goal here, and we are looking into adding options that make sense for most customers and don't add excessive cost or delay to the schedule. We definitely will improve the performance of the unit over the original Mini-T though, because we feel that the Mini-T had sub-par performance on many fronts, and don't want to make the same mistakes. Some of the improvement items we have already decided upon are: * 50 channels GPS with WAAS/EGNOS/MSAS and Position-Hold mode with automatic initialization of the Auto-Survey process by default. Alternatively, the unit can be put into mobile mode, with Auto-Kalman filter optimization depending on vehicle velocity. -160dBm GPS tracking capability * A secondary 10MHz output (SMA or SMB connector, only the connector needs to be stuffed onto the PCB) to have access to the +13dBm output signal * Internal +3.3V antenna supply, that is automatically over-driven by the externally applied antenna supply * USB connector for command/control, RS-232 option, and TTL serial port for legacy compatibility * RoHs 6/6 for compatibility, and RoHs 5/6 option for much longer life and better MTBF than Mini-T * more than 3x better thermal stability, and at the same time more than double the temperature range (+/-5ppb over -40C to +85C versus +/-10ppb from only 0C to +60C) standard, and DOCXO option for even higher thermal stability performance and low-g sensitivity/ruggedized crystal options. * Better phase noise * Status LED's on board * TTL lock/ALARM indicator * External 1PPS input option on unused pin 1 of the main connector * Fully field-upgradable firmware, no FPGA programmer needed * Support for NMEA and SCPI commands * 3-axis accelerometer built-in * lower height: 0.47 inches OCXO height versus 0.75 inches * Much better ADEV performance * Factory-testing for crystal-jumps on every unit We also had several folks ask for alternative frequency outputs, and are currently investigating if we could use the secondary 10MHz connector to add another VCXO to generate any output frequency from 10MHz to 120+MHz such as is done on our ULN-1100 boards. This would add some cost though, and may just end up in a secondary version of the board so that customers who don't need it won't have to pay for it.. The most important item to get feedback on is the TSIP port, we cannot implement the entire TSIP command set as this is quite complex, most customers probably only use a handful of actual commands, and we believe the SCPI/NMEA command/control/status interface is much superior over the proprietary binary TSIP port. We are however open to implement a couple of useful and common TSIP outputs, and would greatly appreciate feedback and suggestions on this, for example a minimum set to make Lady Heather work..? Thanks, Said In a message dated 7/19/2012 13:41:07 Pacific Daylight Time, wb6...@cox.net writes: Hi Said, I know everyone is going to ask for the kitchen sink to be thrown in. BUT, how about just making a replacement that does exactly the same job with no added thrills ? That way your spending the least amount to produce a product and keeps the cost down to the customer which may cause them to want to keep designing with that particular product. just saying BillWB6BNQ ___ 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] Zero-Crossing Detector Design?
The reason I suggested using a schmidt trigger gate is that a schmidt trigger gate switches states at different points at its input. That is, the input positive going switch point is higher than the negative going switch point, maybe half a volt or so. So, driving this gate with a volt RMS or so (3 volts P to P) from the XL-DC should give pretty noiseless, chatter free results. Used to use them all the time to generate 60 Hz square waves from the power mains. Probably work OK at 10 mHz. Al Chris, The simplest zero crossing detector would be to feed your 1 volt, 10 mHz from the XL-DC into the input of an IC with schmidt trigger inputs. You snip ___ 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] Orbital time-delayed angular momentum phasing....???!!
Time-nutters-- Didier Juges asked: What does that do to the focussing properties of the dish? I have seen several descriptions of how the dish needs to be shaped in order to develop the orbital time-delayed angular momentum signal and still achieve an integral focus point. I am not sure that I can describe it, but as I understand it, the dish is not just split and bent into a cork-screw, but that the surface of the dish is also continuously shaped so as to provide a good focus It is just that the signal striking parts of the dish which are increasingly displaced along the axis of the bore-sight are time delayed more or less with respect to other surfaces of the dish. The only way I can see for this to work is for the dish surface to deviate from a true parabolic shape incrementally as each particular area is displaced closer or further away from the focal point. It is a little hard to visualize and a lot harder to find the right words to adequately describe! Mike Baker --- ___ 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] Zero-Crossing Detector Design?
On 7/19/12 4:09 PM, Magnus Danielson wrote: On 07/20/2012 12:33 AM, li...@lazygranch.com wrote: Are you speaking of slew rate limiting in the strict sense of the word, that is a current starved input stage due to the presence of a compensation cap? Or are you using the term slew more vaguely. I am speaking neither. If you have a sine of a particular frequency and amplitude, then you have a known slew-rate, it peaks at 2*pi*f*A, where A is the amplitude of the sine. As you amplify this signal, the slew-rate will grow proportionally. Recall that the jitter of a trigger point is noise divided by slew-rate. This is why we want to increase the slew-rate to a maximum while adding minimal noise. snip nice simple explanation... ___ 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] Poor gps performance this evening ?
Has anyone else noticed poor gps performance this evening ? Both my thunderbolt and my fury are performing quite poorly this evening. I'm seeing 20 ns rms error on my thunderbolt where I would typically see 5.Comparing my fury to an ocxo with a 5370B also shows an un expectedly poor result, while simultaneously comparing the ocxo to an Rb with another 5370B shows the expected result. Both gpsdo's are connected to the same antenna via splitter but the signal levels have not drooped. On the plus side this is giving my gps disciplined Rb a good workout. Regards Mark Spencer Sent from my iPad ___ 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] Zero-Crossing Detector Design?
On Thu, Jul 19, 2012 at 5:47 PM, Rick Karlquist rich...@karlquist.com wrote: Hysteresis does nothing to eliminate jitter or temperature Maybe, but it is absolutely needed if there is any noise on the signal. A perfect comparator with zero hysteresis would dither on every zero crossing. 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.
