[time-nuts] WWVB/Anthorn Re: time-nuts Digest, Vol 195, Issue 27
Hi folks. Just a quick question, but I found a small AM/FM radio here (50p!) with a tiny ferrite rod. Wonder what it uses to set the frequency for AM range? Surely not a tuning diode like MV1404 as these are incredibly expen$ive. Was wondering about pulling the rod and modifying it for WWVB as my existing radio clock works and it would be a shame to mess that up. Should be easy enough as I have (somewhere!) a working LCR meter so can wind a suitable winding over the existing one if its too far off or simply add a couple of layers of Litz wire to approximate the required 65 kHz WWVB. I'd also need to locate a 65 kHz quartz crystal for the XT2 position. External antenna might be better here as it would be very weak indeed being from the USA but there's a couple of methods I can use to improve this like using an optical relay from multiple locations at equidistant points. thanks! Andre From: time-nuts on behalf of time-nuts-requ...@lists.febo.com Sent: 17 October 2020 23:02 Teference to match the DUT. But if you do want to mix both the REF and DUT channels, wouldn't it be better to use a single source to drive both mixers? > > John > > > On 10/17/20 8:59 AM, Gerhard Hoffmann wrote: >> I'm trying to make a quick frequency extender for a timepod. >> MCL PSC2-1 power divider, 2* SRA-1 7 dBm ring mixer, 2 DIL 80 >> MHz-oscillators ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 194, Issue 45 Low lamp voltage Rb
What about using a the hot-air gun technique to migrate the Rb from the walls of the lamp back to the well? David -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Bob kb8tq Sent: 28 September 2020 14:23 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Symmetricom XPRO rubidium Hi > On Sep 27, 2020, at 10:19 PM, Stewart Cobb wrote: > > I have a Symmetricom* XPRO rubidium which appears to be reaching its end of > life. The very sparse manual says that it sets a "service" flag when the > lamp voltage reaches 600 mV. When I got it, that parameter was at about > 540. Several months of continuous runtime later, it's down to about 510. I > assume this is a measure of light emitted by the lamp, but its label is > "lamp voltage". > > I don't want to lose this Rb, because it seems to be the most stable > reference in my lab (about 2x more stable with temperature than a PRS10, by > eyeball). > > Questions for the hive mind: > > (1) Why and how is the lamp voltage falling? What's the wear-out > mechanism? It?s looking at the photo detector on the physics package. The amount of light getting to the photo detector is ?getting low?. Once it gets low enough, the SNR degrades. At some point that gets bad enough for the device to loose lock Yes, essentially this is part of the problem. As others have said Rb adsorbs into the glass and "sticks" outside the pinch resulting in problems very similar to an EOL conventional discharge lamp. In fact I tried to source a broken Rb module (Efratom) with the aim of repairing it using a blue 2W laser + 3 element lens but never managed to get one but got a double oven 10 MHz OCXO instead. About the only good thing with this method vs the hairdrier method is lasers are a *lot* easier to align and aim at just the active part. Get it right and the voltage should improve especially on a no-lock unit to the point that it may then work at least for a while. I obtained this M140 with the intention of using it for etching and other applications. > > (2) Is there any hope of repair? Will the heat gun trick for the LPRO work > on the XPRO? Could I replace the XPRO lamp bulb with one from a young LPRO? The devices are ?aligned? to match up with the bulb. The various tweaks to get that done are never documented on the Telecom Rb?s. You might get lucky, you might not. Yes, make notes for *everything*. Ideally try and take pictures at highest resolution possible to aid with reassembly later. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 194, Issue 36 Lead acid?
Re. OP mentioning battery back up. Just a thought but a lot of places who maintain UPS units have a lot of surplus batteries that are often in reasonable shape. If you're careful and bring a multimeter its possible to snag a good unit which has lost capacity but otherwise works and techniques exist to rebalance units that have failed due to one or more cells going bad. I discovered by accident that taking a SLA that has failed for this reason and *carefully* discharging it from 5-8V to zero over a week then recharging from small solar cell voltage limited to 14.0V will sometimes bring it back: reversed failures on two units from E bikes like this. I actually determined that the repaired NP12-12 was almost as good as a new pack with only marginally higher internal resistance according to meters. -A From: time-nuts on behalf of time-nuts-requ...@lists.febo.com -- End of time-nuts Digest, Vol 194, Issue 36 ** ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 188, Issue 38 EU mains frequency
Hey folks! Re. mains frequency can I modify the scanner here? I think its one of the EM 240 units made by Brennenstuhl It reads voltage and current somewhat accurately, but not frequency. -Andre From: time-nuts on behalf of time-nuts-requ...@lists.febo.com Sent: 25 March 2020 17:59 To: time-nuts@lists.febo.com S ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 188, Issue 22 Re. Pi
Hi, what about using an SDR to micro adjust the 19.2 MHz crystal? I found that replacing the input capacitor (normally 18-27pF) with a reversed blue SMD LED seems to help. Simply pick an LED with the desired reverse capacitance and test. Also feasible: add a 10pF C0G as well if the frequency is too far off to trim in this way. https://www.newark.com/capacitor-types-and-performance Note that most blue LEDs are light sensitive to UV so plan accordingly. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 187, Issue 41
Incidentally its said tha Q Mallory pioneered the use of whispering gallery based timing references, using an old TV delay line in its own temperature controlled oven as an absolute reference to lock on to existing signals. It worked better and used less power than a double oven OCXO but had its own problems notably sensitivity to vibration and not running properly in strong acoustic fields. Mallory later worked out how to solve this by adding a chip based 3 axis accelerometer then replacing the module entirely with a Cs module recovered from a mobile phone base station. From: time-nuts on behalf of time-nuts-requ...@lists.febo.com http://lists.febo.com/pipermail/time-nuts_lists.febo.com/attachments/20200301/3c67c577/attachment.jpg> -- Subject: Digest Footer ___ time-nuts mailing list time-nuts@lists.febo.com http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com -- End of time-nuts Digest, Vol 187, Issue 41 ** ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Pressure senitivity of Rb vapor cell
Incidentally that might be a good experiment. Put a Rb module in a temperature compensated variable pressure chamber with a sensitive (eg BMP350) chip and see what changes. The better units may have this integrated but I doubt it. >From memory this became redundant on the newer generation clocks when the >whole assembly was sealed with (IIRC) pure argon at intermediate pressure to reduce corrosion over time. Could this be one reason why the modules on Galileo broke? Would make sense. Subject: Re: [time-nuts] Pressure sensitivity of Rb vapor cell standards Message-ID: <20200219181647.491f48c3d4849acde93a7...@kinali.ch> Content-Type: text/plain; charset=US-ASCII On Wed, 19 Feb 2020 01:40:56 +0100 Magnus Danielson wrote: > The one thing that one now suffers is that the intensity changes as the > servo pulls it around, I've not seen an explanation of how that is > handled for CW operation. For side-band operation one can use the > AC-modulation amplitude, as one disperse energy from the central carrier. In those systems where they care about this, they use an additional loop, outside of the laser head itself, that uses an acusto-optic modulator to control the intensity. The second paper that I cited in the original mail mentions that as well. Attila Kinali Attila, I believe your original question was how to compensate for atmospheric pressure changes on the cell. It is the cell that is affected by pressure NOT the lamp! This post gives some info. https://www.febo.com/pipermail/time-nuts/2016-May/097829.html Cheers, Corby ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 187, Issue 9 Fake new LPRO 101 Rb's on Ebay
Its possible. Incidentally some of the "old" units have issues but can be fixed as others have found. Still on the hunt for a Rb lamp with or without the casing, as I can probably make use of it even if low voltage as a magnetic sensor or other high tech projects even if no good for a clock. It would help if the metal lamp casing was physically intact but with all the outer bits removed as I probably don't need this due to having a lot of other parts incl the expensive double oven oscillator. Would also make one nerdy case light with an IR filter added. -A From: time-nuts on behalf of time-nuts-requ...@lists.febo.com listed as new may be new old stock, i.e. could they have been backup > units in a box that never got put into service? That would suggest that > they have full life available on the Rb lamp. > -- Subject: Digest Footer ___ time-nuts mailing list time-nuts@lists.febo.com http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com -- End of time-nuts Digest, Vol 187, Issue 9 * ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 187, Issue 6
Re. "fake" LPRO 101 Rb's Not convinced. Some of these are refurbished and actually half decent. I just got due to a shipping error a dual oven OCXO which is very well built though using NOS parts. Re. coronavirus, it appears that once the particles have dried out they are essentially non infectious though its worth mentioning that ambient conditions seem to have an effect due to humidity and UV light. This is incidentally why colds seem to spread more easily in the winter. (snip) Yo Bubba Dudes!, There are two vendors on Ebay selling *new* LPRO 101 Rb's for around $160 each, with discounts for larger purchases.? The general price of a used LPRO seems to be in the $250 to $350 range.? Anybody have any ideas?? (Discount for coronavirus?) In all seriousness, can the coronavirus be transmitted in gear we buy from China or does it require a living host for spreading? Regards, Perrier -- Message: 6 Date: Tue, 04 Feb 2020 07:35:10 + From: "Poul-Henning Kamp" To: Discussion of precise time and frequency measurement Cc: Perry Sandeen Subject: Re: [time-nuts] Fake new LPRO 101 Rb's on Ebay? Message-ID: <80446.1580801...@critter.freebsd.dk> Content-Type: text/plain; charset="us-ascii" In message <1626784396.61618.1580801360...@mail.yahoo.com>, Perry Sandeen via t ime-nuts writes: >In all seriousness, can the coronavirus be transmitted in gear we >buy from China or does it require a living host for spreading? Very few vira can survive 14 days, and for all we know at present that time is sufficient to desinfect 2019-nCov, and to detect any infections. A few specialized infectious agents have the ability to produce "spores" which can survive for *long* periods of time, and then revive on contact with humidity. The best known example is Anthrax. -- /"//Coronaviruses are generally thought to be spread most often by respiratory droplets. Currently there is no evidence to support transmission of 2019-nCoV associated with imported goods and there have not been any cases of 2019-nCoV in the United States associated with imported goods"/ TT > Get an ozone generator and put the contaminated gear to some closed > compartment with it. Turn on the generator and let it be for 15 > minutes. No more any viruses, bacteria or mold there... so it's easy! > (Actually a germicidal LED on a small rotary motor would do the job. These are in the 230 to 315nm range and are used in water sterilizers etc. The ones in nail curing lamps aren't good enough though you may luck out and find a few good diodes that can be repurposed!) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 186, Issue 41 Double Oven
Interesting project. Would a CSAC actually fit? Last I heard these are ridiculously expen$ive (£1000+) assuming you can get one. They are also restricted in some countries it seems. -Andre -- Message: 1 Date: Thu, 30 Jan 2020 12:29:56 -0500 From: Bob kb8tq To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Cesium Mechanical Chronometer Message-ID: Content-Type: text/plain; charset=utf-8 Hi There?s not a lot of ?room? inside the typical Hamilton chronometer. Simply getting an electronic drive gizmo inside (and wires out) would be a major task. Having it work properly with the drive coming and going ?.wow ?. The detent setup is a very fiddly bit in these devices. My *guess* is that a CSAC on a couple of batteries will run longer than the chronometer (before it needs to be wound). If auto winding is part of the mix, that gets even more into the ? wow ? region. Bob End of time-nuts Digest, Vol 186, Issue 41 ** ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 186, Issue 21 Atomic clock unit?
Hi, does anyone have an atomic clock (Rb or Cs) module for sale in the UK please? thanks, Andre Note: A not working (ie low lamp voltage) one at a good price may be acceptable. Its actually to calibrate my meters as it seems a lot of the cheaper ones even though initially calibrated aren't anywhere near as accurate especially as time goes on. My Black Star 2400 is at least .4 kHz out on the 10 MHz internal clock. I did some fine tuning using local radio as a reference but this isn't perfect. From: time-nuts on behalf of time-nuts-requ...@lists.febo.com Sent: 16 January 2020 17:00 To: time-nuts@lists.febo.com Subject: time-nuts Digest, Vol 186, Issue 21 Send time-nuts mailing list submissions to time-nuts@lists.febo.com (snipped) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 174, Issue 35
Hi, This is also relevant to my experiments with SDR. For my purposes I added a reverse biased blue LED to each pin on the crystal. On my radio reversing it so the crystal was on the back revealed the two pads someone had forgotten to put capacitors on explaining one of the problems. This seems a good approach and as blue LED capacitance is a factor of applied voltage it gives me a further parameter to play around with. Note, this sent the offsets to hell but I can correct for it in software. Next step: hacking the memory and connector so it can work on USB 3.1 just for the heck of it, as the chip does in fact support this mode but the pins aren't populated. DISCLAIMER: If you blow up your SDR/laptop/etc please don't come crying to me. Hi On a ?chip" based setup like this, it?s a matter of pulling the TCXO and putting in some wires. Whatever frequency the TCXO used to supply, that?s what your magic external device needs to provide. The designers do not seem to allow you to provide a variety of input frequencies. Given how the input gets used for all sorts of things, that?s not as crazy as it sounds. The option to pull the TCXO and fiddle has been there for quite a while. At some point they will move the TCXO function inside the ?chip" package (with MEMS or some other magic). Once they do, the ability to tear it off will become a bit more difficult?. :) Once you do replace the TCXO, you then are very dependent on a sawtooth correction to run your GPSDO. The PPS becomes one big long hanging bridge and thus is not useful. Carrier phase or (like in the TBolt) code phase data could be used as an alternative to a sawtooth correction word. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Black Star counter defunct
Hi, does anyone have any idea why a "Black Star" 2.4GHz counter would stop working on all ranges? Display updating fine and buttons work but signal has no effect on any of the 3 input BNCs. The oscillator looks OK but to be honest this was calibrated sometime in 1997 so it may just be too old :-( thanks, -Andre From: time-nuts on behalf of time-nuts-requ...@lists.febo.com Sent: 30 September 2018 18:27 To: time-nuts@lists.febo.com Subject: time-nuts Digest, Vol 170, Issue 48 Send time-nuts mailing list submissions to time-nuts@lists.febo.com T > What's a clever, simple, reliable (pick 2 of 3) way to get 16 MHz out of 10 > MHz? Low phase noise isn't a big requirement and jitter doesn't need to be > sub-nanosecond. The main requirement is perfect cycle count accuracy. This is > for driving a 16 MHz microcontroller from a 10 MHz Rb/Cs/GPSDO. 10 MHz input > is likely sine; 16 MHz output is 3v3 or 5v CMOS. > > Thanks, > /tvb I would say some sort of TCXO crystal oscillator PLL'd to the original signal using tuning diode on one leg of the crystal. A good way to get one is to strip down an old USB to LAN module or even an optical mouse, 16 MHz is also used in Arduinos. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 170, Issue 36 Happy Equinox!
Hi, has anyone noticed the "Autumn Equinox" on their weather station/etc? just popped up with a message. Also does anyone have a list of weather stations that have time signal (MSF) receivers in them please? Kind regards, Andre ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest Faulty Efratom
Hi, am I right in saying that these typically sell for about £80-£160 used? this one seems to have a lock problem but I am not sure without looking at it. ebay /itm/273424114165 maybe bad lamp but not totally hopeless if so. Pretty sure its repairable but need to figure out what parts to buy in advance so that I have a fair chance of success, even no_lock is useful for certain applications. I am also wondering if anyone still wants the broken 22 GHz security modules here as they are otherwise surplus to requirements. Kind regards, -Andre #include "firetwinklersandlightballs.h" From: time-nuts on behalf of time-nuts-requ...@lists.febo.com Sent: 13 September 2018 17:00 To: time-nuts@lists.febo.com Subject: time-nuts Digest, Vol 170, Issue 26 Send time-nuts mailing list submissions to time-nuts@lists.febo.com To subscribe or unsubscribe via the World Wide Web, visit http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com or, via email, send a message with subject or body 'help' to time-nuts-requ...@lists.febo.com You can reach the person managing the list at time-nuts-ow...@lists.febo.com When replying, please edit your Subject line so it is more specific than "Re: Contents of time-nuts digest..." Today's Topics: 1. Re: time-nuts Digest, Vol 170, Issue 25 (Dan Kemppainen) 2. Re: Looking for a reference oscillator called XRef-VS made by VK3HZ for TS-2000 (Wayne) 3. Re: Looking for a reference oscillator called XRef-VS made by VK3HZ for TS-2000 (Dave ZL3FJ) -- Message: 1 Date: Wed, 12 Sep 2018 13:51:29 -0400 From: Dan Kemppainen To: time-nuts@lists.febo.com, time-nuts-requ...@lists.febo.com Subject: Re: [time-nuts] time-nuts Digest, Vol 170, Issue 25 Message-ID: <4762c49d-5843-be28-17d3-85c7837d4...@irtelemetrics.com> Content-Type: text/plain; charset=utf-8; format=flowed Bob, I think what you want is the SX-Key editor, which includes the compiler and programmer and help files. https://www.parallax.com/downloads/sx-key-editor-software In fact, just earlier today I programmed SX processor on a board... Dan On 9/12/2018 12:00 PM, time-nuts-requ...@lists.febo.com wrote: > Message: 3 > Date: Tue, 11 Sep 2018 22:40:08 +0200 > From: "Robert LaJeunesse" > To:time-nuts@lists.febo.com > Subject: Re: [time-nuts] Loran-C Simulation > Message-ID: > > > > Content-Type: text/plain; charset=UTF-8 > > FWIW there exists an online reference for SX BASIC > athttp://www.piclist.com/techref/parallax/sxb/sxb/___index.html which may > prove helpful in understanding the SX-B code. > > Unfortunately I can not find the SX-B BASIC compiler online > anymore.http://www.parallax.com/sx/sxb.asp is 404. > > Bob L. -- Message: 2 Date: Wed, 12 Sep 2018 16:43:04 -0700 From: "Wayne" To: , "'Discussion of precise time and frequency measurement'" Subject: Re: [time-nuts] Looking for a reference oscillator called XRef-VS made by VK3HZ for TS-2000 Message-ID: <001301d44af2$5d71b0e0$185512a0$@splawn.ws> Content-Type: text/plain; charset="us-ascii" Hi Bo, The AutoPLL does look promising. I think I'll have a discussion with Steen about my application and perhaps order the unit for testing. Thank you for your input. Much appreciated. 73 Wayne, WA7NE -Original Message- From: time-nuts On Behalf Of Bo Hansen Sent: Wednesday, September 12, 2018 1:43 AM To: time-nuts@lists.febo.com Subject: Re: [time-nuts] Looking for a reference oscillator called XRef-VS made by VK3HZ for TS-2000 Hi Wayne I am not 100% sure but can you use the this AutoPLL: <http://oz5n.dk/AUTO-PLL.htm> Availability: <http://oz5n.dk/> Bo, OZ2M ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. -- Message: 3 Date: Thu, 13 Sep 2018 22:26:08 +1200 From: "Dave ZL3FJ" <2c...@silverbears.nz> To: "'Discussion of precise time and frequency measurement'" Subject: Re: [time-nuts] Looking for a reference oscillator called XRef-VS made by VK3HZ for TS-2000 Message-ID: <019401d44b4c$2f83c6f0$8e8b54d0$@silverbears.nz> Content-Type: text/plain; charset="us-ascii" There's a device- also originating in VK land- in prototype testing phase at present that is similar to the x-Ref and reputed to be much cheaper. No idea when it will be available. 73 Dave, ZL3FJ -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Wayne Sent: Thursday, September 13, 2018 11:43 To: timen...@rudi
Re: [time-nuts] time-nuts Digest, Vol 169, Issue 40 SRD ideas
Hi, if its of any help I (still) have a box of goodies including some 10 and 22 GHz Gunnplexers. would the diodes be of any use? The RX (IIRC its a varactor) diode is structurally very similar to an SRD, maybe possible to adapt it if as I expect the resonance is tuned to near 6 GHz by "cooking" it under controlled conditions. If its a close harmonic the diode might pull fine. I think the parameters would need tuning but I have four (!) of them and some other bits which you are welcome to test. Joe Gwinn > Regards > Paul > WB8TSL > > On Mon, Aug 27, 2018 at 8:03 PM, ed breya wrote: > >> I forgot to mention: >> >> If you've been diagnosing by swapping parts, be aware that changing the A3 >> is the same as changing the SRD - they won't necessarily match anymore, so >> would need adjustment. >> >> Maybe your original SRD was just fine, but the whole set needed >> adjustment. Who knows what may have been tweaked or mis-tweaked by >> individuals working on it previously. If the original SRD is intact, just >> check to see if it's still a diode (should look the same as a regular Si >> diode, with maybe a little higher forward voltage drop). If so, it's >> probably OK and can be returned to service. >> ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 168, Issue 21 SDRs and precision time
Hi, has anyone ever combined an SDR and Anthorn atomic clock receiver module so that they can be synchronized? the idea here is as a variant of a thinned array similar to WebSDR but using lots of smaller units to get around the thinned aray curse (tm) and combining signals with suitable offset delays so that signal increases at the expense of noise. -Andre From: time-nuts on behalf of time-nuts-requ...@lists.febo.com Sent: 23 July 2018 17:00 To: time-nuts@lists.febo.com Subject: time-nuts Digest, Vol 168, Issue 21 Send time-nuts mailing list submissions to time-nuts@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] RE. Re: WTS: Efratom PTB-100 Precision Timebase (Don@True-Cal)
Message: 2 Date: Wed, 11 Jul 2018 07:54:33 -0500 From: "Don@True-Cal" To: "'Discussion of precise time and frequency measurement'" Subject: Re: [time-nuts] WTS: Efratom PTB-100 Precision Timebase Message-ID: <015001d41916$5151d780$f3f58680$@gmail.com> Content-Type: text/plain; charset="us-ascii" Thanks everyone for the insightful comments. I've been inspired by off-list help to get this unit working primarily because of the quality of the internal FRK. If nothing else, it has been a tremendous learning experience and after numerous hours studying the manual and bench testing I find myself knowing far more about optical pumping and Rb absorption lines than I thought I ever wanted to know. I keep you posted if I have a breakthrough. Regards, Don Incidentally it might be worth mentioning this. Sulfur is a common breakdown of some encapsulants and atmospheric pollution can be a major headache as H2S though in barely detectable quantities can erode the surface mount and other components if they are exposed. Do any of the components on your unit look even slightly tarnished, if so they will fail soon. I've had this problem with Xbox handsets before possibly due to sulfur from handling. Even a set of digital scales failed due to being in a shed next to PCB etching equipment. I also noticed that sometimes a precision resistor will drift due to heat, as mentioned in the repair guides it can affect even parts near a heat source. -Andre ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
