Re: [time-nuts] 5370B / TimeLab question

On 12/2/20 10:17 AM, djl wrote: or: https://ntrs.nasa.gov/citations/19870019361 from Charlie Greenhall A nicer looking version is available at https://ipnpr.jpl.nasa.gov/ click the 1980-189 button use your browser's search function for Greenhall.. https://ipnpr.jpl.nasa.gov/progress_report/

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

On 12/1/20 11:03 AM, Hal Murray wrote: kb...@n1k.org said: Yes, there’s more to it if you want to get connections in and out. Forget about “hermetic� connectors, they aren’t up to the task. You need glass to metal seals embedded in the structure. Now you have even more constraints on

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

On 11/30/20 1:22 PM, Art Sepin wrote: To me it looks more like water ingress through micro-cracks in the plastic-dome, and the O-ring did its job and kept that water in. Interesting. That's the first we've heard about micro-cracks in the Radome but that's certainly a likely possibility wit

Re: [time-nuts] Voyager space probe question

On 11/30/20 2:20 AM, Gerhard Hoffmann wrote: Am 30.11.20 um 07:00 schrieb Mark Sims: I once bought a spool of tungsten-rhenium alloy wire on ebay for dirt cheap. A few weeks later a guy contacted me and offered a lot of money for it. Turns out they used it to rebuild TWTs. 1. I used to live

Re: [time-nuts] Voyager space probe question

On 11/30/20 2:20 AM, Gerhard Hoffmann wrote: Am 30.11.20 um 07:00 schrieb Mark Sims: I once bought a spool of tungsten-rhenium alloy wire on ebay for dirt cheap. A few weeks later a guy contacted me and offered a lot of money for it. Turns out they used it to rebuild TWTs. 1. I used to live

Re: [time-nuts] time-nuts Digest, Vol 196, Issue 31

On 11/29/20 10:38 AM, lstosk...@cox.net wrote: Great fun to have the guys who were there share War Stories on how things were done. But I'm the kind of guy who buys some machine tool on eBay and then looks up the name on the WEB to see something about the guy that used it (angle block at GM,

Re: [time-nuts] Voyager space probe question

On 11/29/20 3:53 AM, Hal Murray wrote: jim...@earthlink.net said: I don't know about Voyager, but on the SDST and later, the auxosc is a TCXO with fair to middling performance. A good part of the "art" of communicating with an "old" spacecraft is knowing/predicting/guessing where the "best l

Re: [time-nuts] Voyager space probe question

On 11/28/20 2:51 PM, Bill Notfaded wrote: Good evening Don- I believe FEI made the USO's for Voyager1, 2, and others: http://adsabs.harvard.edu/full/2004ESASP.544..131A More recently, APL has also been supplying USOs. Quartz, in a vacuum bottle for thermal isolation. Lots of blanks started

Re: [time-nuts] Voyager space probe question

On 11/28/20 2:28 PM, Steve Allen wrote: On Sun 2020-11-29T11:06:18+1300 donald collie hath writ: Can any group member describe the onboard frequency reference[s] used in the Voyager space probes? They have done extremely well over the decades - are they Cesium?, Rubidium?, Quartz? The ultra st

Re: [time-nuts] Flicker Noise Reduction

On 11/18/20 7:15 PM, Richard (Rick) Karlquist wrote: On 11/18/2020 5:27 PM, jimlux wrote: The proposed mitigation technique relies on tracking the rapid gain variations in the radiometer due to 1/f noise and correcting them by generating a baseline state in the first amplification stage of

Re: [time-nuts] Flicker Noise Reduction

On 11/18/20 4:59 PM, Richard (Rick) Karlquist wrote: I suspect that, whatever this is, only applies to 1/f mechanisms specific to THz, based on the last sentence.  One of my former clients did a PhD at Stanford on 1/f noise and his dissertation certainly had no magic bullets to mitigate 1/f noise

Re: [time-nuts] Survey grade antennas

On 11/18/20 2:49 PM, Charles Steinmetz wrote: Stu wrote: >> The usual auction site has a few true survey grade antennas for a very good >> price. Search for Novatel GPS-703-GGG. These cover all three frequency >> bands (L1, L2, L5), which is still unusual to find in surplus. Bob wrote: …

Re: [time-nuts] WWVB teensy BPSK early experiments

On 10/31/20 7:26 PM, Bob kb8tq wrote: Hi On Oct 31, 2020, at 9:45 PM, jimlux wrote: On 10/31/20 4:46 PM, Bob kb8tq wrote: Hi Looking at the data sheet for the MCU, they really do want 24 MHz and that’s about it. I suspect you would do better to take your 10 MHz OCXO and run it into one

Re: [time-nuts] WWVB teensy BPSK early experiments

ts of chips. Super fine wires to very small pads. But at least at the moment perhaps thats not critical to developing something. I did tinker with delay and will need to use a scope at this point to see the effects. Regards Paul. On Sat, Oct 31, 2020 at 7:35 PM jimlux wrote: On 10/31/20 11:42 AM

Re: [time-nuts] WWVB teensy BPSK early experiments

was with a Teensy 3.1 - I had a lot of them, so I wasn't afraid to hack it up. Bob On Oct 31, 2020, at 7:17 PM, jimlux wrote: On 10/31/20 11:42 AM, Bob kb8tq wrote: Hi …..errr….. Can you pull the clock oscillator off the Teensy board? (Yes, the soldering iron would be involved). Wil

Re: [time-nuts] WWVB teensy BPSK early experiments

On 10/31/20 11:42 AM, Bob kb8tq wrote: Hi …..errr….. Can you pull the clock oscillator off the Teensy board? (Yes, the soldering iron would be involved). Will the clock input to the MCU accept something like 10 MHz? If so solder on a cable …. At that point whatever the Teeny does is locked to

[time-nuts] power supply for Z3801

The 48-ish volt power supply for my Z3801 gave up the ghost.. What's the latest in off-the-shelf power supplies (external is fine, uncased is fine)? There were plenty of suggestions on the list a few years back, and I can pick one of those up, but hey, someone else might have walked this path

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

On 10/27/20 6:16 PM, Tom Van Baak wrote: Alberto, Thanks for asking. The correct spelling is Allan variance or Allan deviation, named after David Allan, of NBS (NIST). Yes, on rare occasions it is misspelled Allen, as in the hex key wrench. Note it's spelled correctly in the Subject line of t

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

On 10/27/20 11:00 AM, Alberto di Bene wrote: On 2020-10-27 17:38, Andy Talbot wrote: They use Allen variance, TDEV and MTIE plots. Is "Allen variance" just the British way of spelling "Allan variance", or are they two different things ? 73  Alberto  I2PHD It's David Allan's name, and ref

Re: [time-nuts] Looking for "The Theory and Design of Quartz Crystal Units" by V.Bottom

On 10/24/20 3:14 PM, Bob kb8tq wrote: After it’s sealed up (and possibly processed a bit after seal) you test it to see how you did. Some number will be ok, the rest head into the trash. The good ones go into oscillators. Is that 5% or is that 80% … depends on what you are after …. Bob The

Re: [time-nuts] WWVB Dephaser Question

On 10/24/20 3:53 PM, paul swed wrote: Antenna and filtering are not a problem for me. I use the 10' X 10' square loop and about 800' of wire with a cap to resonate at 60 KHz and then a preamp really to drive 140' of coax. Currently using a modified KD2BD receiver frontend but using a 350 Hz xtal

Re: [time-nuts] Looking for "The Theory and Design of Quartz Crystal Units" by V.Bottom

On 10/23/20 6:50 PM, Wes wrote: Attila, Amazon says (Out of print):  * Publisher : McMurray Press; 1st Edition (January 1, 1968)  * Language: : English  * ASIN : B0007H97C8 Not exactly the same book but the same author: "Introduction to quartz crystal unit design"  There seems to be a cop

Re: [time-nuts] Frequency Counter Choice

Prologix... but as a hack...) @jimlux: Take a look at the following project: https://github.com/Twilight-Logic/AR488 and https://www.eevblog.com/forum/projects/ar488-arduino-based-gpib-adapter/ https://oshpark.com/profiles/artag For more details or if you need a PCB for the Arduino Micro (32u4

Re: [time-nuts] Frequency Counter Choice

On 10/22/20 12:08 PM, Oz-in-DFW wrote: On 10/22/2020 11:52 AM, jimlux wrote:  I wonder if one could implement the protocol using GPIO pins on something like a Beagleboard or Arduino clone? (yes, as a product, with the right connector and line driver/receivers, etc. - it would cost the same as

Re: [time-nuts] Frequency Counter Choice

On 10/22/20 8:29 AM, Tom Van Baak wrote: 3) Instead of replacing the front panel readout, instead do all your comms over SCPI, to the point where you have created a virtual instrument, not unlike some of the logic analyzer or 'scope PC apps. This solution would be very welcome by lots time-n

Re: [time-nuts] What's available in the way of DSP for new WWVB?

On 10/16/20 1:54 PM, jimlux wrote: On 10/16/20 9:08 AM, Graham / KE9H wrote: On Tue, Oct 13, 2020 at 12:19 PM paul swed wrote: Graham take a look earlier in the thread there are details about the teensy. There is actually a lot of hardware out there today for little money. Thats what makes

Re: [time-nuts] What's available in the way of DSP for new WWVB?

On 10/16/20 9:08 AM, Graham / KE9H wrote: On Tue, Oct 13, 2020 at 12:19 PM paul swed wrote: Graham take a look earlier in the thread there are details about the teensy. There is actually a lot of hardware out there today for little money. Thats what makes the SDR DSP approach interesting and f

Re: [time-nuts] WWVB Dephaser Question

On 10/12/20 11:23 PM, John C. Westmoreland, P.E. wrote: Paul, Sure - even on my OpenHPSDR system using my vertical antenna - I am almost able to decode WWVB (reliably) using the clock program from: http://f6cte.free.fr/index_anglais.htm with no changes whatsoever. If I 'fix' the antenna - I'm

Re: [time-nuts] WWVB Dephaser Question

On 10/12/20 7:40 AM, paul swed wrote: John really appreciate the pointer. Though it doesn't help wwvb BPSK its a really good intro to SDR and DSP super simple. A good way to get your feet wet. Hmmm is there a parts order soon? :-) Regards Paul WB8TSL And the teensy has plenty of space and spee

[time-nuts] phase noise webinar from IEEE MTT-S

https://www.naylornetwork.com/mtt-mkt2019/email01.asp?projID=122255 There's a registration link at the above page. Low Phase Noise Signal Generation Utilising Oscillators, Resonators & Filters and Atomic Clocks Tuesday, October 13, 2020 - 12:00 PM Eastern Daylight Time Abstract: Oscilla

Re: [time-nuts] David Allan amusing notes on ADEV, MDEV, TDEV etc.

On 10/7/20 6:00 AM, Tom Van Baak wrote: "Dave's Story on how GPS helped NASA/JPL synchronize their Deep Space Network tracking stations" https://ethw.org/w/images/a/ac/Allan_OH_-_GPSandtheDeepSpaceNetwork.pdf "they flew me out to Goldstone in their corporate jet to look at that facility, "

Re: [time-nuts] Spectracom 8161 "Standard Frequency Receiver - Oscillator" for WWVB (and question...)

On 10/5/20 3:59 AM, Magnus Danielson wrote: Hi, On 2020-10-05 11:20, Hal Murray wrote: On a WWVB setup you get 10’s of us ( yes microseconds) of movement at sunrise and sunset. You get as much as 10us between day and night. Somehow, I was thinking that WWVB was ground wave and wouldn't be

Re: [time-nuts] Phase Noise and ADCs

-nuttery. You have to test it and see what it is. for instance, the AD9650 has a specified aperture uncertainty specified as jitter of, say, 0.08 picosecond, rms. And they don't specify what the clock input bandwidth is. On Sep 26, 2020, at 12:28 PM, jimlux wrote: On 9/26/20 8:10 AM,

Re: [time-nuts] Phase Noise and ADCs

On 9/26/20 8:10 AM, John Ackermann N8UR wrote: We know that phase noise scales with frequency, so if you multiply frequency by 10 you get a 20 dB increase in noise. What I don't fully understand is how that relationship works with other than simple multiplication/division. For example (and m

[time-nuts] backup power (was BVA has been sold)

On 9/25/20 11:07 PM, Poul-Henning Kamp wrote: Bill Notfaded writes: Can't I just use a high quality APC backup power system like we use to power racks of gear in our Telco and compute closets? Very few UPS's are good at long-run applications, they are typically built to run a heavy

Re: [time-nuts] Brand new OCXO/TCXO reccomenations

they were for a space application.. Regards, Mark W7MLG On Fri, Sep 25, 2020, 11:51 AM jimlux wrote: On 9/25/20 8:55 AM, Mark Goldberg wrote: Note that many (maybe all) TCXOs exhibit a hysteresis effect when the temperature cycles. The stability reported on the datasheets is onl

[time-nuts] distribution amps for 200 MHz

For work, I'm looking to distribute 200 MHz to 44 widgets.. The usual SRS, etc. boxes max out at 100 MHz. Any ideas? (The going in position is "buy a bunch of minicircuits amps and dividers and assemble it") Tnx Jim ___ time-nuts mailing list -- ti

Re: [time-nuts] WWVB SDR discussion

On 8/10/20 11:45 AM, paul swed wrote: Hello to the group. Have been looking forward to seeing how the STM32 SDR project might be going. SDR is a weak spot for me. So been reading. And believe the answer is that a SDR solution may work for AM code and even BPSK code to an extent. But doesn't the s

Re: [time-nuts] eLORAN in the Antipodes ? (was: Re: eLORAN will be on the air GRI 99600)

On 8/7/20 4:13 PM, Bill Byrom wrote: See this 1961 IRE paper at the NIST website: https://tf.nist.gov/general/pdf/2303.pdf IRE merged with AIEE in 1963 to form IEEE. Figure 7 shows the calculated amplitude transfer of the ground wave signal vs frequency and distance. Note that for 100 kHz signa

Re: [time-nuts] eLORAN will be on the air GRI 99600

On 8/6/20 4:28 PM, Forrest Christian (List Account) wrote: If you look at generally-available GNSS PNT solutions, you'll find a few failure modes: 1) Loss of a satellite (or two). This is why the constellations have more satellites than is strictly necessary, so not a big deal. 2) Loss of con

Re: [time-nuts] eLORAN will be on the air GRI 99600

On 8/6/20 2:22 PM, Bill Notfaded wrote: Isn't there also CDMA? We used a EndRun Technologies system not long ago that used a small short antenna that could be located inside and didn't need a cable to the roof for a GPS antenna. This was handy for rooms that couldn't have anything penetrate the

Re: [time-nuts] eLORAN will be on the air GRI 99600

On 8/6/20 9:17 AM, Taka Kamiya via time-nuts wrote: Someone in this thread mentioned "at least 2 satellite time and frequency solutions" exists already.  I only know of GPS (GNSS) constellations.  What's the other? Transit? I don't believe they are still operational, though. I wonder if on

Re: [time-nuts] another source of time...

was a big Type II burst (associated with Coronal Mass Ejections) (and a few type III bursts, which are more common,and a lot faster) It's not the best to see the diurnal variation in propagation, but look at the top part of the plots above 1 MHz. Mark On 05-Aug-20 3:44 PM, jimlux wr

[time-nuts] another source of time...

I was researching potential calibration sources for our orbiting receivers (where we need to line up GNSS signals with HF signals) and after looking at the usual suspects like WWV, we came across another one. Ionosondes - they're all over the place, and these days, they're fairly accurately ti

Re: [time-nuts] eLORAN will be on the air GRI 99600

On 8/5/20 12:40 PM, Tom Knox wrote: Hi Paul and Magnus; Not to mention one space EMP would kill all the Sat systems, where a ground base system even if affected would be easy to access for repair. The vulnerability of GNSS systems to EMP attacks is not all that high - GPS is, after all, a DoD

Re: [time-nuts] WWVB PM Time Questions

On 7/31/20 11:25 AM, Scud West wrote: Back in December 2018 there was a WWVB thread. From Poul-Henning's post on 2018-12-05 quoting John N8UR: "While everyone's been talking :-) , I recorded some WWVB IQ data for folks to play with. You can download it from http://febo.com/pages/wwvb/ The r

Re: [time-nuts] Raspberry Pi NTP server

On 7/15/20 5:59 AM, Hal Murray wrote: tpie...@gmail.com said: It seems like it would not be that hard to get the USB frame sequence phase locked to the system clock. One would need a way to measure the phase offset of the USB S-o-F vs the system clock, and then it's a standard process to phase

Re: [time-nuts] Raspberry Pi NTP server

On 7/15/20 5:16 AM, Petr Titěra wrote: On 15.07.2020 0:13, Trent Piepho wrote: On Mon, Jul 13, 2020 at 4:52 PM Hal Murray wrote: Is there any way for a USB device to synchronise with the CPU clock (perhaps via the USB framing) so that a special-purpose device could timestamp the PPS occurren

[time-nuts] Precise timing through USB was Re: Raspberry Pi NTP server

On 7/13/20 4:37 PM, Hal Murray wrote: Is there any way for a USB device to synchronise with the CPU clock (perhaps via the USB framing) so that a special-purpose device could timestamp the PPS occurrence with respect to CPU time ? If you were designing a special purpose device, just add a cou

Re: [time-nuts] Just any counter external reference and discipline mode.

On 7/13/20 11:27 AM, paul swed wrote: Taka I firmly believe the first answer to your question is cost. Was the counter an economical unit or higher quality. My 5335 counters have seriously cheap xtal clocks and an external reference makes a big difference. But the larger costly generators and cou

Re: [time-nuts] Just any counter external reference and discipline mode.

On 7/13/20 9:58 AM, Taka Kamiya via time-nuts wrote: I'm sorry to interject a newbie question  I changed the title to distinguish from rest of the conversation. I have heard this both ways about external references - whether it's used to phase lock internal source and used directly after s

Re: [time-nuts] HP 5316B External Reference

On 7/13/20 9:02 AM, Richard (Rick) Karlquist wrote: On 7/13/2020 6:26 AM, Wes wrote: Hi Magnus, I did have the manual when I posed the original question but I had not delved into the cal procedure until you mentioned it.  It seems to be a bit complicated for what it does. I wonder how stabl

Re: [time-nuts] Raspberry Pi NTP server

On 7/12/20 7:15 AM, Hal Murray wrote: stevesommars...@gmail.com said: I'd like to reduce the USB polling contribution by polling at 125 microseconds as the Linux PPS folks suggest (http://linuxpps.org/doku.php/ technical_information)Would an FTDI-based USB convertor do the trick? It depend

Re: [time-nuts] Raspberry Pi NTP server

On 7/11/20 1:30 PM, Steven Sommars wrote: Using GPIO with an RPi is a good direction, of course. That wasn't my question. Some data may help explain. Configuration = RPi4 (raspbian buster) Uputronics RPi GPS board (includes PPS) connected to GPIO pins. This is the time of day sour

Re: [time-nuts] Raspberry Pi NTP server

On 7/9/20 2:14 AM, Petr Titěra wrote: Just one note. Most USB to serial chip claim USB2.0 support but they only provide Full-Speed data transfers. That is data communication protocol based on USB1.1 parameters with 1ms polling interval. You have to specifically look for High-Speed (i.e 480mbps)

Re: [time-nuts] Raspberry Pi NTP server

On 7/8/20 4:40 PM, Hal Murray wrote: stevesommars...@gmail.com said: My RPi4 (Raspbian Buster) has a GPS+PPS/USB. Serial->USB uses Prolific PL2303, which supports USB 2.0 which means 1 msec polling of the PPS signal. I've been unable to poll more frequently As far as I know, the PL2303,

Re: [time-nuts] Raspberry Pi NTP server

On 7/8/20 4:40 PM, Hal Murray wrote: stevesommars...@gmail.com said: My RPi4 (Raspbian Buster) has a GPS+PPS/USB. Serial->USB uses Prolific PL2303, which supports USB 2.0 which means 1 msec polling of the PPS signal. I've been unable to poll more frequently As far as I know, the PL2303,

Re: [time-nuts] Raspberry Pi NTP server

On 7/4/20 7:49 AM, David J Taylor via time-nuts wrote: David, I've seen your comparison in the list archives. However, none of the approaches I have seen published so far (including yours) exploit all the possibilities I mentioned. The Raspi having better community support doesn't help if the p

Re: [time-nuts] Raspberry Pi NTP server

On 7/4/20 2:30 AM, David J Taylor via time-nuts wrote: ... and it has much less general support ... and it generates more RF interference ... and it costs money as the OP already has the Raspberry Pi I have both Pis and BB Blacks and Greens and Green wireless. I'm interested in the RF i

Re: [time-nuts] low power divide by 5

On 7/2/20 2:50 PM, Bob kb8tq wrote: Hi On Jul 2, 2020, at 5:30 PM, jimlux wrote: On 7/2/20 11:37 AM, ed breya wrote: It's been fun reminiscing about all these dividers and techniques, but getting back to the OP, the original search was for a divide by 5 with "low power" and

Re: [time-nuts] low power divide by 5

On 7/2/20 2:13 PM, Peter McCollum wrote: Another way to achieve divide-by-N is with a non-retriggerable one-shot, adjusted to the appropriate time value. Back in the 40's/50's, the common tube circuit was called a Phantastron (really, look it up!). Phantastron dividers were used in several of the

Re: [time-nuts] low power divide by 5

On 7/2/20 11:37 AM, ed breya wrote: It's been fun reminiscing about all these dividers and techniques, but getting back to the OP, the original search was for a divide by 5 with "low power" and operation from 5 to possibly 3.3V, and clocking properly at 50 MHz. One would assume also minimal siz

Re: [time-nuts] low power divide by 5

On 7/2/20 6:48 AM, Tom Van Baak wrote: > I'm surprised nobody has suggested using the 12AX7 or 6J6 dual triodes. Jim, Funny, just yesterday I was looking at the design of a laboratory cesium beam standard from 1963. Sorry, there's no divide-by-5 example in there. But the attached images show

Re: [time-nuts] low power divide by 5

On 7/1/20 11:21 PM, Gerhard Hoffmann wrote: Am 02.07.20 um 00:35 schrieb jimlux: On 7/1/20 1:41 PM, ed breya wrote: Yeah, I know. I was just lamenting the lack of nice medium-density count functions in 74AC. It's hard to beat the simplicity of a '390 when you 16 bore holes just

Re: [time-nuts] 30 MHz freq adjust by Hz

On 7/1/20 4:59 PM, Bob kb8tq wrote: Hi Um …. e ….. If the phase spur is at 1.5 Hz at 10 MHz, it still will be at 1.5 Hz at 1296. The multiplication process does not change the offset frequency. What you *do* get is a change in level. If the spur is 40 db down at 10 MHz, then it goes

Re: [time-nuts] low power divide by 5

On 7/1/20 1:41 PM, ed breya wrote: Yeah, I know. I was just lamenting the lack of nice medium-density count functions in 74AC. It's hard to beat the simplicity of a '390 when you Anyway, I've always liked having a wide assortment of MSI logic devices available in all families, that you jus

Re: [time-nuts] low power divide by 5

On 7/1/20 5:24 AM, Detlef Schuecker via time-nuts wrote: Hi, there are three JK-FF, with Q1 as MSB, Q3 as LSB. J1,K1 ist input to Q1, etc. . There are 8^6 possibilties (6 inputs to the Qx or QxNOT or to HIGH or to LOW) of which 2069 generate a cycle length of 5. The following wiring will genera

Re: [time-nuts] low power divide by 5

On 6/30/20 5:04 PM, Richard (Rick) Karlquist wrote: On 6/30/2020 3:47 PM, dschuecker wrote: Hi, a divide by five should possible with a synchronous state-machine made of 3 ( sufficiently fast-) JK-FlipFlops. All 3 FFs are clocked with the input freq. , the outputs of the FFs are fed back t

Re: [time-nuts] low power divide by 5

On 6/29/20 10:41 AM, ed breya wrote: 74AC logic would do it just fine, but needs 5V nominal for full-speed specs. Lower supply voltage should work, but probably not all the way down to 3.3V with 50 MHz clocking. The spec sheets should indicate the possible range. The 74AC390 can provide divid

[time-nuts] low power divide by 5

What logic family might be appropriate for a divide by 5 from 50 to 10MHz, low power, running off 3.3 or 5V? ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com

Re: [time-nuts] time sync by moonbounce

ut I have one with the same antenna used for other purposes. Sorry for the bandwidth, but the thread brought me old memories. Best regards, Ignacio El 23/05/2020 a las 19:17, jimlux escribió: On 5/23/20 9:18 AM, Mike Millen wrote: Probably a good idea... there are two page 19s and no page 20 in

Re: [time-nuts] Interesting application for really nutty timing

On 6/2/20 3:24 PM, Tim Shoppa wrote: Hal, at one point shortly after their discovery in the late 60’s, Pulsars were considered as a possible primary frequency standard. Then atomic clocks became more amenable as lab standards. As to time-nut measurements on pulsars, check this out: https://ar

Re: [time-nuts] TAPR TICC and TADD-2 Minis

On 6/2/20 2:06 PM, Tom Holmes wrote: Frank... What is interesting is that all of your traces appear to be identical except for the vertical scale factor, which suggests that the ringing you are seeing, which is much improved from your earlier plots, is still a little bit of a problem. I am go

[time-nuts] differences among TADD-2, TADD-3, PulsePuppy, TADD-2 mini

I'm trying to distinguish among all these options.. TADD-2 and TADD-3 are 5/10 in, multi out - 3 is just a new 2? TADD-2 mini is 1,2.5,5,10 in and one out PP has a way to solder a packaged oscillator on the board, lower power, and puts out 1, 10, and 100pps. ___

Re: [time-nuts] time sync by moonbounce

On 5/23/20 8:19 AM, Jeremy Nichols wrote: Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a c

Re: [time-nuts] NYTimes: New geoid soon

On 5/23/20 11:52 AM, Steve Allen wrote: On Fri 2020-05-22T23:16:49-0700 Hal Murray hath writ: It is a fiendishly difficult math and physics task that, once completed, will have taken a decade and a half to accomplish. So fiendishly difficult that the first time the task was completed was not u

[time-nuts] time nuttery in Space Communications

One thing in all these DSN histories is that they don't make very much of the essential thing that separates Deep Space radio links from Near Earth radio links, and that's the timing: specifically the coherent link between the received signal and transmitted signal. I suspect that's just becau

Re: [time-nuts] time sync by moonbounce

On 5/23/20 9:18 AM, Mike Millen wrote: Probably a good idea... there are two page 19s and no page 20 in the pdf.  :-( That's the page where the aliens came and told us how to build the DSN, then the story resumes with 26m antenna design and operation. (If anyone's interested, I can probab

Re: [time-nuts] time sync by moonbounce

On 5/23/20 8:19 AM, Jeremy Nichols wrote: Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a c

[time-nuts] time sync by moonbounce

Apparently, they used moonbounce between DSN stations to synchronize to 5 microseconds in 1968. It was easier and cheaper than flying cesium clocks around. (And the Rb standards weren't good enough). https://ntrs.nasa.gov/search.jsp?R=19770007245 History of DSN - mostly about politics, history

Re: [time-nuts] potential low-RFI power supply

as a load. --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Monday, May 18, 2020, 1:49:04 PM EDT, jimlux wrote: On 5/18/20 10:19 AM, Joseph Gwinn wrote: On Mon, 18 May 2020 12:00:02 -0400, time-nuts-requ...@lists.febo.com wrote: Re: time-nuts Digest, Vol 190

Re: [time-nuts] potential low-RFI power supply

On 5/18/20 10:19 AM, Joseph Gwinn wrote: On Mon, 18 May 2020 12:00:02 -0400, time-nuts-requ...@lists.febo.com wrote: Re: time-nuts Digest, Vol 190, Issue 30 Message: 1 Date: Sun, 17 May 2020 12:53:42 -0600 From: Eric Scace To: Time Nuts email list Subject: [time-nuts] potential low-RFI power

Re: [time-nuts] potential low-RFI power supply

On 5/17/20 11:53 AM, Eric Scace wrote: Pro Audio Engineering announced a sale (through Friday) on its nominal 14 Vdc 4A switching supply . The test results we

Re: [time-nuts] f-multipliers from VHF to 10 GHz

On 5/15/20 2:14 PM, Gerhard Hoffmann wrote: No, no, no, it's not that bad :-)  I should not post here in the middle of the night. Sorry to cause that confusion. Minimum  is -90 dBc @ 50 Hz, or let's say @100 Hz @ 10 GHz. that would equal -110 dBc@1 GHz,   or -130 dBc @100 MHz, BTDT. That's m

Re: [time-nuts] f-multipliers from VHF to 10 GHz

On 5/14/20 5:58 PM, Gerhard Hoffmann wrote: I have a potential project in the electron spin spectroscopy sector and I need one or two clean signal sources in the 10 GHz range. Phase noise at, say, 50 Hz offset is important, but anything below 110 dBc  does not care. That probably calls for a mu

Re: [time-nuts] Teensy 4.1

On 5/14/20 3:14 PM, Adrian Godwin wrote: I just saw an update to the Teensy microcontroller line. Teensys are somewhat like an arduino but generally with faster processors and more memory. The latest one, 4.1, has an ethernet interface with IEEE1588 packet timestamping. https://www.pjrc.com/cat

[time-nuts] measuring timing variation in a web conference.

A practical data source has become available for me to look at. The lab had a virtual town hall, and one of the senior managers has a pendulum clock in the background. And, there were obvious drops in the video stream, because the pendulum would "jump" (it was commented on by viewers - "That st

Re: [time-nuts] OCXO Support Board

On 5/13/20 5:56 AM, Bob kb8tq wrote: Hi There are a number of free ( = there is no license fee ) pcb layout programs out there. One of the many is KiCad. It’s not that hard to use. It is very popular. There are a lot of YouTube videos and blogs detailing how to do this or that with it. Laying

Re: [time-nuts] (no subject)

On 5/12/20 10:22 AM, Bruce Hunter via time-nuts wrote: Attached are a couple of pictures of these curious oscillators.  As there are no mounting holes to secure these, I assume they were held in a clamping arrangement.There appears to be a threaded thermometer well in the front and a frequency

Re: [time-nuts] Vectron MC2003X4-001W Oscillator

On 5/12/20 10:18 AM, paul swed wrote: OK its a reverse mini 9 pin. It will be expensive I suspect as its mil. Or just find some pins stick them in with wires for temp. Is it a MicroD? There are some inexpensive plastic connectors that are compatible (I can't remember the part number, but if th

Re: [time-nuts] Quality of timing mode GPS vs survey accuracy

On 5/8/20 3:38 PM, Charles Steinmetz wrote: Jim wrote: I'm attaching a screen shot of 4 receivers, taken at the same time (within seconds,not time-nuts same time) All sitting on the table together. One might expect closer agreement if all of the receivers were fed from one antenna through a

Re: [time-nuts] Quick check of a GPS controller oscillator

On 5/6/20 7:07 PM, Sanjeev Gupta wrote: On Wed, May 6, 2020 at 8:22 PM Bob kb8tq wrote: If all of that sounds like a lot of work (or not complete enough), buy a second ( or third or fourth ….) GPSDO. Next get a couple Rb’s …. maybe a Cs or three …. have you looked into Masers? :) AT, AT.

Re: [time-nuts] an interesting timing problem

On 5/6/20 7:33 AM, Chris Howard wrote: At my current job we were looking into delay timings of video systems. We were doing end-to-end measurement by putting a time display in front of a monitor and have the camera show both the time display and the monitor. It looks a bit like the old infini

[time-nuts] an interesting timing problem

Given that there's a lot more people spending time zooming, webexing, teaming, skype, facetime, etc. these days, I'm curious if anyone has figured out to *quantify* the issues of lag, desynchronization, etc. How would one go about instrumenting it (without access to the source code or servers

Re: [time-nuts] Interesting 1-60 MHz =/- 50 ppb Stratum-3 TCXO chip

On 5/1/20 5:00 PM, Richard Solomon wrote: Where do you buy these ? Their web site was not too illuminating. digikey and mouser carry a lot of SiTime parts, including eval boards. Tnx, Dick, W1KSZ On Fri, May 1, 2020, 4:31 PM mp...@clanbaker.org wrote: Hello, time Nutters-- I have been

Re: [time-nuts] power supplies

On 5/1/20 12:07 PM, Tim Shoppa wrote: Jim, when it comes to "bench supplies" - knobs for voltage and meters - most of the commonly available Chinese bench supplies in the under 3A-range are linear with series regulator. This unit (HY1803D) is typical and has a transformer (relay-selected winding

Re: [time-nuts] power supplies

On 5/1/20 1:11 PM, Mark Sims wrote: Yes, Power Designs units are VERY good. Some (their precision models) are insanely good. They have a cult following and can be a bit pricey these days. There are lots of posts on eevblog.com about them. Dave did a video on one of the precision units. h

[time-nuts] power supplies

What with telework, I'm doing more timenuts-ey stuff at home, and the power supply conundrum has come up. There's a plethora of interesting widgets scattered across my bench requiring variously, 5V, 8V, 12V, and 15V. I've got a box full of various fixed voltage supplies, mostly linear, picke

Re: [time-nuts] Hetrodyning concept

On 4/27/20 7:39 AM, Gary Chatters wrote: Your basic error is that you are adding the two sine wave signals.  Get that idea out of your head. When mixing two signals (heterodyne) you multiply them:     Vout = Asin(2pi*f1*t + p1) * Bsin(2pi*f2*t + p2)    ^--

Re: [time-nuts] On choosing reasonable synthesizer PN requirements

On 4/24/20 5:52 AM, David J Taylor via time-nuts wrote: Hi The “wiggles” he is chasing are about 2-3 Hz (by eyeball on his charts). At 2.4 GHz, that is a fairly convenient ~1 ppb. The Z-3801 (if it was in good health) should be easily able to hold that level of performance. It’s not clear whic

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