ITAR has their own restrictions for GPS receivers. See here: http://www.fas.org/spp/starwars/offdocs/itar/p121.htm
"(2) Designed for producing navigation results above 60,000 feet altitude and at 1,000 knots velocity or greater;" ________________________________________ From: [email protected] [[email protected]] on behalf of [email protected] [[email protected]] Sent: Friday, February 01, 2013 1:02 PM To: [email protected] Subject: time-nuts Digest, Vol 102, Issue 122 Send time-nuts mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of time-nuts digest..." Today's Topics: 1. Re: GPS at 60,000 feet (Chris Albertson) 2. Re: Low noise power supplies? (Poul-Henning Kamp) 3. Loran again (Rich and Marcia Putz) 4. Re: Low noise power supplies? (Charles P. Steinmetz) 5. Re: Low noise power supplies? (Adrian) 6. Re: Low noise power supplies? ([email protected]) 7. Re: Low noise power supplies? (Bob Camp) ---------------------------------------------------------------------- Message: 1 Date: Thu, 31 Jan 2013 13:09:27 -0800 From: Chris Albertson <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] GPS at 60,000 feet Message-ID: <cabbxvhshvqykznepkcdpnexikvavr0sytuhrvdudu10vmrd...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 > I know for sure my handheld Garmin works at 27000 feet, at > 530mph... ...I was actually surprised it worked up there. > It made me wonder what the actual limits are. What are the limits of your hand held unit or what are the limits of GPS in general. I think GPS works as long as you are under the orbit of the satellites. The company I used to work for placed GPS on some low orbit spacecraft, so say roughly 200 miles up and 18,000 mph but I'd guess most hand held units would not work in those conditions Chris Albertson Redondo Beach, California ------------------------------ Message: 2 Date: Thu, 31 Jan 2013 22:03:29 +0000 From: "Poul-Henning Kamp" <[email protected]> To: Tom Van Baak <[email protected]>, Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] Low noise power supplies? Message-ID: <[email protected]> Content-Type: text/plain; charset=ISO-8859-1 -------- In message <C7259FFFCD3E42C2815B939BA386A0A8@pc52>, "Tom Van Baak" writes: >We have rigorous ways to compare and report oscillator performance; >both as numbers and as plots. Is there something equivalent for >power supplies? Phase Noise measured on a 0Hz carrier ? If you want the dynamic behaviour, it gets much more tricky, because then you have both the spectrum of the load-changes and the supply-changes, resulting in a spectrum output from the PSU. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [email protected] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ------------------------------ Message: 3 Date: Thu, 31 Jan 2013 19:01:29 -0500 From: "Rich and Marcia Putz" <[email protected]> To: <[email protected]> Subject: [time-nuts] Loran again Message-ID: <F4410DBD97D74D7D98878858B47F5323@MAINCOMPUTER> Content-Type: text/plain; charset="iso-8859-1" Hi all; I'm hearing Loran C signals @ 7:00 pm EST hear northern Indiana this evening. Anyone else? Rich W9ENG ------------------------------ Message: 4 Date: Thu, 31 Jan 2013 19:20:16 -0500 From: "Charles P. Steinmetz" <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] Low noise power supplies? Message-ID: <[email protected]> Content-Type: text/plain; charset="us-ascii"; format=flowed tvb wrote: >I'll answer the question with anther question -- how does one >properly measure power supply noise? Does it boil down to a single >number, a couple of key numbers, or is it a plot, or several plots? There are a number of "standard" ways, some of which have been mentioned by others, none of which is all that helpful IMO. What I find most useful is a plot of noise density vs. frequency from, say, 0.1 Hz to as high as you require. The data should be taken and processed with sufficient frequency resolution to show any spurs in the band of interest. It is often helpful to have several plots, each covering part of the band of interest, to improve the displayed resolution of spurs. NOTE: Designing a preamp for collecting the data is far from trivial. Articles have been written about it (see, for example, Linear Technology Application Note 124 by Jim Williams <www.linear.com/docs/28585>). Best regards, Charles ------------------------------ Message: 5 Date: Fri, 01 Feb 2013 01:51:33 +0100 From: Adrian <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] Low noise power supplies? Message-ID: <[email protected]> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Charles, thanks for posting. That is the LTC application note I had in mind. And here is Bruce's contribution to low noise PS design and measurement: http://www.ko4bb.com/~bruce/LowNoisePowerSupplies.html Don't miss to scroll fully down. There is a link to an IEEE paper discussing chemical battery noise measurement. Adrian Charles P. Steinmetz schrieb: > tvb wrote: > >> I'll answer the question with anther question -- how does one >> properly measure power supply noise? Does it boil down to a single >> number, a couple of key numbers, or is it a plot, or several plots? > > There are a number of "standard" ways, some of which have been > mentioned by others, none of which is all that helpful IMO. > > What I find most useful is a plot of noise density vs. frequency from, > say, 0.1 Hz to as high as you require. The data should be taken and > processed with sufficient frequency resolution to show any spurs in > the band of interest. It is often helpful to have several plots, each > covering part of the band of interest, to improve the displayed > resolution of spurs. > > NOTE: Designing a preamp for collecting the data is far from > trivial. Articles have been written about it (see, for example, > Linear Technology Application Note 124 by Jim Williams > <www.linear.com/docs/28585>). > > Best regards, > > Charles > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ------------------------------ Message: 6 Date: Thu, 31 Jan 2013 20:13:40 -0500 (EST) From: [email protected] To: [email protected] Subject: Re: [time-nuts] Low noise power supplies? Message-ID: <[email protected]> Content-Type: text/plain; charset="ISO-8859-1" Or a good battery as a source for the regulators as discussed in this thread already. It's quite nice to have all the different Voltages available at the same time, with up to 200mA. bye, Said In a message dated 1/31/2013 13:12:33 Pacific Standard Time, [email protected] writes: Hi For $393.75 does it come with a wall wart? If not I would definitely go for a "medical" ground isolated / low leakage version to power the beast. The added cost over a plain jane wall wart won't add much to the purchase price percentage wise. Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, January 31, 2013 3:58 PM To: [email protected]; [email protected] Subject: Re: [time-nuts] Low noise power supplies? Not sure if anyone posted this here yet, but Abracom has a very low noise (7nV/RtHz at 1KHz) power source for VCO's etc, with various outputs. It's sold on DIgikey or Mouser I think. Here is a review of that unit: _http://jaunty-electronics.com/blog/category/reviews/_ (http://jaunty-electronics.com/blog/category/reviews/) Co-incidentally he also has a review of one of our units on the same page. This is a very handy and reasonably priced power supply for many low-noise type of experiments. bye, Said In a message dated 1/30/2013 21:36:50 Pacific Standard Time, [email protected] writes: Lester Veenstra wrote: > The typical test supply on a bench for clean VCO testing is a small gel cell > battery. For a regulated power supply, make one using a 723. The 723 has > far lower noise out than the monolithic regulators. > > Depends on the variety of 723 some are noisier than others. Some use an internal zener reference, some use a bandgap reference. The original used a zener reference. Bruce > Lester B Veenstra M?YCM K1YCM W8YCM > [email protected] > > 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 > US cell +1-304-790-9192 > UK cell +44-(0)7849-248-749 > Guam Cell: +1-671-929-8141 > Jamaica: +1-876-456-8898 > > 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: [email protected] [mailto:[email protected]] On > Behalf Of Richard (Rick) Karlquist > Sent: Wednesday, January 30, 2013 9:17 PM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Low noise power supplies? > > > I know this topic has been discussed in the past on the list, but a > colleague is asking if there are any off the shelf low noise power supplies > for testing oscillators. Something a cut above an HP "brick" lab power > supply etc. They are hoping to avoid having to homebrew a power > conditioning circuit. > Did we ever arrive at a concensus as to the state of the art in homebrew > power conditioning circuits? > > Any help would be appreciated. > > Rick Karlquist N6RK > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ------------------------------ Message: 7 Date: Thu, 31 Jan 2013 21:02:32 -0500 From: Bob Camp <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] Low noise power supplies? Message-ID: <[email protected]> Content-Type: text/plain; charset=us-ascii Hi If you are driving a spectrum analyzer, the 10,000X mentioned in the app note simply is not needed. A gain of 10X or less will get you to below 2 nv / sqrt(Hz) at 100 Hz and beyond. A 10 Hz blocking cap does not need to be a "24 hours to stabilize" device. An AD 797, a couple of metal film resistors, and a fairly large (say 47 uf) plastic cap work pretty well. Bob On Jan 31, 2013, at 7:20 PM, Charles P. Steinmetz <[email protected]> wrote: > tvb wrote: > >> I'll answer the question with anther question -- how does one properly >> measure power supply noise? Does it boil down to a single number, a couple >> of key numbers, or is it a plot, or several plots? > > There are a number of "standard" ways, some of which have been mentioned by > others, none of which is all that helpful IMO. > > What I find most useful is a plot of noise density vs. frequency from, say, > 0.1 Hz to as high as you require. The data should be taken and processed > with sufficient frequency resolution to show any spurs in the band of > interest. It is often helpful to have several plots, each covering part of > the band of interest, to improve the displayed resolution of spurs. > > NOTE: Designing a preamp for collecting the data is far from trivial. > Articles have been written about it (see, for example, Linear Technology > Application Note 124 by Jim Williams <www.linear.com/docs/28585>). > > Best regards, > > Charles > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ------------------------------ _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts End of time-nuts Digest, Vol 102, Issue 122 ******************************************* _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
