Re: [time-nuts] Measuring power supply noise
Robert wrote: HP 3552A Transmission Test Set. Designed for testing telephone lines, its basically an AF signal generator, level meter, frequency meter, monitor amplifier and line iterface in a portable box. Ignoring the generator, the line interface will allow direct connection to supplies of up to 75V and the level meter measures noise down to -90dBm (600ohm) with low pass filters available. * * * Its specified for 40Hz to 60kHz but responds down to 10Hz. * * * A quick check of a switching supply gave -42dBm at 450Hz off load and -45dBm at 1.5KHz at 28mA. A nice general purpose audio tester that is not well known. Cost was less than $40. Brings back fond memories of the HP and other TTSs. For power supplies used to run precision oscillators, though, one probably would like something that performs well below 10 Hz and with noise levels in the tens of nV range rather than the 3552's noise floor of tens of uV. A nice, quiet preamp will solve the latter problem, but you'd have to tear into the 3552 to conquer its LF limit. When one gets serious about quiet regulators for oscillators, one has to think about what's inside the can. Often, there is an internal regulator with 10-1000 times the noise of your carefully-designed regulator (and, in the case of a GPSDO, digital circuitry trying to put noise on the oscillator supply, as well). Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Small DMTD project PCBs Group Buy Update, boards are here !
Packing them up to take to the PO. Paypal to stanley_reyno...@yahoo.com $9.50 per board $47.50 for the set of 5. If you mail your payment to: Stanley Reynolds 225 Alpine Street Birmingham, AL 35210 then $9 per board $45 for the set of 5. Yes I have plenty of extra boards. Notice arrow has a good price on the DDS chip. I have no plans to provide parts except if someone is unable to complete the project otherwise. Stanley ___ 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] PTS 040 manual
Hi, I need a manual for my PTS 040 synthesizer, it has developed a minor problem and I need the information. I was able to locate manuals for the PTS 160, 500, 3200 and X10, but not for my 040. Also I have the programming information, which is common for some models. I was surprised that this model is still in production, but I didn't asked PTS since I bought mine for about $75 and the manual can cost much more. I usually buy manuals for all my stuff, but only if the prices are consistent with that I paid for the real equipment. Do you anybody have a copy of it or know any link for buying or downloading? I think this is not OT since this kind of equipment can be considered time nut class :-) . TIA, Ignacio EB4APL ___ 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] PTS 040 manual
Hi, I need a manual for my PTS 040 synthesizer, it has developed a minor problem and I need the information. I was able to locate manuals for the PTS 160, 500, 3200 and X10, but not for my 040. Also I have the programming information, which is common for some models. I was surprised that this model is still in production, but I didn't asked PTS since I bought mine for about $75 and the manual can cost much more. I usually buy manuals for all my stuff, but only if the prices are consistent with that I paid for the real equipment. Do you anybody have a copy of it or know any link for buying or downloading? I think this is not OT since this kind of equipment can be considered time nut class :-) . TIA, Ignacio EB4APL ___ 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] Freestanding mast
Just a thought, as you are in southern hemisphere, wouldn't you see more birds facing North? Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Steve Rooke Sent: 03 September 2010 5:32 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Freestanding mast If your nearby houses and obstructions are not high, IE. if the houses there are single story, you may be able to get away with what I have done. Instead of fixing something on the house, I've attached a couple of antenna to the top of one of my washing line poles in the garden as this faces South (I'm in the Southern Hemisphere) and I get an average of 7-8 sats every day and up to 12 at night. It makes any maintenance easy, if you get any snow it is easy to clear at that height, there is much less windage if your subject to strong winds and, if you don't use your washing line, the size of the poles make them quite rigid so you don't suffer a lot of noise that you would high up on a thin pole. Just a thought. Steve On 3 September 2010 12:46, Charles P. Steinmetz wrote: > I'm curious what the best freestanding mast is for a timing antenna > (think Lucent timing antenna or marine "mushroom" GPS antenna -- light > and pretty small). The mast would have its highest support at rooftop > or chimney-top level, and could extend from there as far downward as > the ground with additional supports as required. Should be able to > survive at least Category 2 winds and heavy snow and ice. > > What reasonably available mast material no more than, say, 3" in > maximum cross-section would allow the most vertical extension above > the highest support, and how much extension would that be? I'm thinking 10 feet of 2" > or so thin-wall steel tube may be OK, but beyond that I don't know. > Tubing is probably not the optimum shape, but I assume the > availability of other engineering shapes (say, "+" cross-section) is likely to be limited. > > Ideas? > > Thanks, > > 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. > -- Steve Rooke - ZL3TUV & G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Measuring power supply noise
Kewl idea, I have used TIMS's for 30 years or so and owned one for the last 10 years. Inever thought of using one to measure power supply noise. Well done. Nic VK2KXN / VK5ZAT There was a thread about power supply noise a while ago and the difficulty of measurement. I've just got hold of a piece of test equipment that I've been after for a while that is good for comparative checks. It's an HP 3552A Transmission Test Set. Designed for testing telephone lines, its basically an AF signal generator, level meter, frequency meter, monitor amplifier and line iterface in a portable box. Ignoring the generator, the line interface will allow direct connection to supplies of up to 75V and the level meter measures noise down to -90dBm (600ohm) with low pass filters available. The frequency meter is PLL based and locks on to the predominent frequency. Its specified for 40Hz to 60kHz but responds down to 10Hz. The line interface also has a switchable constant current "hold" circuit that lets you add a 28mA load. The speaker allows you to listen to the noise. A quick check of a switching supply gave -42dBm at 450Hz off load and -45dBm at 1.5KHz at 28mA. A nice general purpose audio tester that is not well known. Cost was less than $40. Robert G8RPI. ___ 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] Measuring power supply noise
There was a thread about power supply noise a while ago and the difficulty of measurement. I've just got hold of a piece of test equipment that I've been after for a while that is good for comparative checks. It's an HP 3552A Transmission Test Set. Designed for testing telephone lines, its basically an AF signal generator, level meter, frequency meter, monitor amplifier and line iterface in a portable box. Ignoring the generator, the line interface will allow direct connection to supplies of up to 75V and the level meter measures noise down to -90dBm (600ohm) with low pass filters available. The frequency meter is PLL based and locks on to the predominent frequency. Its specified for 40Hz to 60kHz but responds down to 10Hz. The line interface also has a switchable constant current "hold" circuit that lets you add a 28mA load. The speaker allows you to listen to the noise. A quick check of a switching supply gave -42dBm at 450Hz off load and -45dBm at 1.5KHz at 28mA. A nice general purpose audio tester that is not well known. Cost was less than $40. Robert G8RPI. ___ 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.
