Re: [time-nuts] [timenuts] GPS L1 chokering antenna
Hi there, something about the power supply. If it's an older Leica choke ring antenna, it uses an AeroAntenna antenna element. Perhaps there is still a label on the lower side of the choke ring. L1L2 antennas had the part number AT2775-..., L1 had been AT575-... The power supply is coded there. AT2775-20W--xxx-xx-xx-xx || | | +--- magnet (if available) || | +-- antenna gain (00=passive, 12=12dB ... || +- supply voltage (00=passive,05=+5V,RG=+5..+18V |+- cable length [inch] +-- connector type ... same with AT575. Best regards Martin ___ time-nuts mailing 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] Jitter Test on Dividers
In message 4ab6b76d.1010...@rubidium.dyndns.org, Magnus Danielson writes: Seems less likely. I was pondering if the power line frequency was doing some nice beat frequency with the system... 1250 seconds at 50Hz = 62500 periods. Assume one extra period over 1250 seconds: 62500 + 1 = 62501 Relative frequency precision: 62501/62500 = 1.16 = 16 PPM. In your dreams :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing 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] Solartron 7150plus DMM Failure
Hi All Apologies to any who may receive multiple copies of this but I thought it worth sending to those lists where I've previously seen mention of this meter. I have now had two identical failures of Schaffner filtered mains sockets on ex-mil 7150plus DMMs, although I'm not suggesting the ex-mil source is particularly relevant. In both cases there has been an internal component failure within the mains socket that caused it to emit smoke around the edges of the metal filter cover, accompanied by a brown goo and a very unpleasant smell. The brown goo is deposited inside the meter in the area of the filter, and very messy it is too, with a small amount seemingly contained within the smoke and splattering on adjacent external surfaces. In neither case did the meter stop working, or even pause to cough:-), so I'm assuming it's most likely to be the parallel capacitor directly across the line input that's failed. According to the Schaffner schematic there's no varistor in there, which might have been a preferred suspect, but there are two series inductors followed by two more capcitors, one between each power line and ground. After the failure the meter can continue to be used as it stands but really needs a strip down and good internal clean in the area of the mains socket, and even then it's still likely to smell unpleasant. I don't have time at the moment but will open up the filters eventually and see what might be done to rebuild or just bypass them. Just cleaning the filter internally too would probably help reduce the lingering smell. As a general precaution I would suggest, at the very least, standing these meters on a sheet of plastic and, if there's anything reasonably close behind it, wall etc, folding the plastic up behind it too as extra protection. The unit that failed here today was sitting on the top shelf of a test bench with its back fairly close to the wall, the wall is looking better after a good clean but is still not very pretty! A longer term fix might be to remove the filter components entirely and use an external inline filter if required, there isn't much spare room inside the unit so I don't think an internal stand alone would be an option. 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] Jitter Test on Dividers
Poul-Henning Kamp wrote: In message 4ab6b76d.1010...@rubidium.dyndns.org, Magnus Danielson writes: Seems less likely. I was pondering if the power line frequency was doing some nice beat frequency with the system... 1250 seconds at 50Hz = 62500 periods. Assume one extra period over 1250 seconds: 62500 + 1 = 62501 Relative frequency precision: 62501/62500 = 1.16 = 16 PPM. In your dreams :-) I didn't bother doing the math before I dismissed it. Seemed unlikely for starters... the AC theory seemed more likely. 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] I'm all of a dither.
Hi, A fellow amateur and I have just put together the GPS-based frequency reference published in the Every day Practical Electronics issue of April/May 2009 and are both experiencing the same problem. The type-3 phase comparator of the 74HC4046 has both 1-pps and 50kHz DC-coupled inputs designed to produce an error pulse due to the difference between their leading edges. However, the longer pulse dominates the output because it holds the latch in thrall despite the 50kHz pulse trying to grab a little of the action. My question is then, are there variants of the 74HC4046 that have a type-3 detector which is edge-drive only? Natch, I can AC-couple and clamp them but I just wondered. I know that in the past that there have been differing versions of the old CD4046 and now, of course, there are also the '7046 and '9046 types around. Cheers - Joe G3LLV ___ time-nuts mailing 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] Solartron 7150plus DMM Failure
gandal...@aol.com wrote: I have now had two identical failures of Schaffner filtered mains sockets on ex-mil 7150plus DMMs, although I'm not suggesting the ex-mil source is particularly relevant. In both cases there has been an internal component failure within the mains socket that caused it to emit smoke around the edges of the metal filter cover, accompanied by a brown goo and a very unpleasant smell. Interesting. There's what, nearly half a dozen reported failures now? - 2 of yours - 1 of mine - and someone else who emailed me the other day about possible alternatives to the Schaffner filter unit It is, in all likelihood the X2-rated mains filter cap that's blowing -- I've seen a similar fault on BBC Micros when the X2 caps fail in those, which causes the same brown smoke emission. In those, however, the smoke doesn't usually condense and stick... I suspect if I ever get another 7150+, I'll be swapping the line filter on the instrument's arrival... -- Phil. li...@philpem.me.uk http://www.philpem.me.uk/ ___ time-nuts mailing 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] I'm all of a dither.
Joe McElvenney wrote: Hi, A fellow amateur and I have just put together the GPS-based frequency reference published in the Every day Practical Electronics issue of April/May 2009 and are both experiencing the same problem. The type-3 phase comparator of the 74HC4046 has both 1-pps and 50kHz DC-coupled inputs designed to produce an error pulse due to the difference between their leading edges. However, the longer pulse dominates the output because it holds the latch in thrall despite the 50kHz pulse trying to grab a little of the action. My question is then, are there variants of the 74HC4046 that have a type-3 detector which is edge-drive only? Natch, I can AC-couple and clamp them but I just wondered. I know that in the past that there have been differing versions of the old CD4046 and now, of course, there are also the '7046 and '9046 types around. Cheers - Joe G3LLV Joe That looks to be an exact copy of the crude GPS reference published in Silicon Chip in March 2007 and April 2007 with corrections (synchronous frequency divider chips were cascaded incorrectly ) in the May 2007 issue. March 2007: http://www.siliconchip.com.au/cms/A_108508/article.html April 2007: http://www.siliconchip.com.au/cms/A_108617/article.html May 2007: http://www.siliconchip.com.au/cms/A_108798/article.html The question is did they include the corrections or not? Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I'm all of a dither.
Joe McElvenney wrote: Hi, A fellow amateur and I have just put together the GPS-based frequency reference published in the Every day Practical Electronics issue of April/May 2009 and are both experiencing the same problem. The type-3 phase comparator of the 74HC4046 has both 1-pps and 50kHz DC-coupled inputs designed to produce an error pulse due to the difference between their leading edges. However, the longer pulse dominates the output because it holds the latch in thrall despite the 50kHz pulse trying to grab a little of the action. My question is then, are there variants of the 74HC4046 that have a type-3 detector which is edge-drive only? Natch, I can AC-couple and clamp them but I just wondered. I know that in the past that there have been differing versions of the old CD4046 and now, of course, there are also the '7046 and '9046 types around. Cheers - Joe G3LLV Joe Found the 3 relevant issues and as I suspected without the correct divider connections the 50kHz output may misbehave due to glitches on the 74HC160 TC output. The correct circuit actually eliminates the inverter between the 74HC160s by cascading them synchronously. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Jitter Test on Dividers
And a FYI - it was 60 hertz power here Magnus Danielson wrote: Poul-Henning Kamp wrote: In message 4ab6b76d.1010...@rubidium.dyndns.org, Magnus Danielson writes: Seems less likely. I was pondering if the power line frequency was doing some nice beat frequency with the system... 1250 seconds at 50Hz = 62500 periods. Assume one extra period over 1250 seconds: 62500 + 1 = 62501 Relative frequency precision: 62501/62500 = 1.16 = 16 PPM. In your dreams :-) I didn't bother doing the math before I dismissed it. Seemed unlikely for starters... the AC theory seemed more likely. 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] Jitter Test on Dividers
Brian Kirby wrote: And a FYI - it was 60 hertz power here Never let flimsy details like facts derail a perfectly good theory. (That's about 13,33 ppm BTW) 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] HP8660 ALC Question
Gentlemen, has anyone of you ever experiend problems with the ALC regulation loop of a HP8660C/D synthesizer that had its origin in a problem with the level detector's reference diode? TIA for your help. Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
