[time-nuts] Reminder -- upcoming list changes

Just a reminder that starting this Friday, June 15, postings to the febo.com mailing lists will need to use the new addresses -- @lists.febo.com instead of @febo.com. You can start using the new addresses now. The list server will be shut down for an hour or two on Friday to make the

[time-nuts] febo.com Mailing List Changes

Some of you may know that febo.com lives on leased hardware at a data center. That hardware is now at its end of service life, which means it won't be supported if it breaks. After pondering the options for a replacement, I've decided that it's time to move away from dedicated hardware

Re: [time-nuts] Possible new run of TNS-BUF High Isolation, Low Noise Buffer Amp boards

yet, there's still time. John On 05/08/2018 03:09 PM, John Ackermann N8UR wrote: Back in October, 2016, TAPR did a build-to-order offering of the TNS-BUF low noise, high isolation buffer amplifier.  The original 2016 post is attached below.  All of those units sold out, and recently I've

[time-nuts] A Request to the List

TVB is traveling and not on-line as much as usual, so in his absence I'm going to ask everyone to please consider his request a couple of weeks ago to think before you post. Please keep in mind that time-nuts isn't a chat room, and that every message doesn't require an individual response.

[time-nuts] Possible new run of TNS-BUF High Isolation, Low Noise Buffer Amp boards

. Best regards, John Forwarded Message Subject: [time-nuts] TNS-BUF High Isolation, Low Noise Buffer Amp Available Date: Wed, 5 Oct 2016 10:15:46 -0400 From: John Ackermann N8UR <j...@febo.com> I've previously mentioned a high performance buffer amplifier called the &q

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Long ago I did some WWVB signal-to-noise measurements with an HP 3586C selective voltmeter (commonly used by the FMT-nuts).  I measured the signal power at 60.0 kHz with 20 Hz bandwidth.  Then I measured the power a small offset plus and minus  (100 Hz?  I don't recall), and took the mean of

Re: [time-nuts] Wavecrest DTS2075

It's more a burst-mode and averaging analyzer like the HP 5371/5372.  But it can do sustained time interval measurements if you mess around enough with the settings.  And the resolution is down in the very low picoseconds. But it's big, awkwardly shaped, and has a jet turbine fan. John On Apr

Re: [time-nuts] Cheap jitter measurements

I want to jump on Tom's post, and Bob's note at 1:14 on Saturday (that begins with "Just to be very clear..." They both raise an important point about measurements. With both NTP and GPSDO measurements a lot of folks focus heavily on what the "black box" is reporting about itself. But

Re: [time-nuts] Ultralink

Hi Brooke -- Yes, all the chips on the board are low power devices. I'm measuring the receiver as drawing 0.9 MA at about 2.3 volts. Update -- I moved the receiver and farted around with the wiring, and now the S-Meter is off the peg, responds to orientation changes, and I actually got a

Re: [time-nuts] Ultralink

On 03/30/2018 03:39 AM, Hal Murray wrote: t...@leapsecond.com said: I updated http://leapsecond.com/museum/ulio/ with more manuals, and many exterior / interior photos of the 301 module. Thanks. My 301 says it is a 30TH Rev-A - mostly through hole parts. Same layout. Mine is the same.

Re: [time-nuts] Ultralink WWVB receiver manuals?

of 6 pins are Vcc, TCO, AGC, gnd. /tvb - Original Message - From: "John Ackermann N8UR" <j...@febo.com> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Thursday, March 29, 2018 8:57 AM Subject: [time-nuts] Ultralink

[time-nuts] Ultralink WWVB receiver manuals?

I just acquired an Ultralink WWVB timecode receiver -- more specifically, model 301 receiver and model 333 decoder. I'm looking for documentation on these guys. Anyone have a manual they'd be willing to share? The key questions are really just two: (a) is the 6P6C modular cable connecting

Re: [time-nuts] Introduction, new list member, Ms Tisha Hayes, AA4HA

The impedance mismatch with the A or B models is't a real issue unless you're doing precise amplitude measurements.  Lots of folks use them for FMT work without issues. There are adapters available or buildable to deal with the odd Telco connectors. John On Mar 29, 2018, 3:04 AM, at 3:04 AM,

Re: [time-nuts] ULN regulator with more current capability than LT3042?

Thanks, all. I think I'll end up using the 3042 with pass transistor, partly for reasons of cost. I have no idea whether paralleling two 3042s would result in lower noise from the device, and there are already three or four fairly pricey chips on the board. I appreciate all the info! John

Re: [time-nuts] ULN regulator with more current capability than LT3042?

Thanks, Bruce!!! On 03/18/2018 04:19 PM, Bruce Griffiths wrote: Use an LT3045, its the 0.5A version of the LT3042. Bruce On 19 March 2018 at 09:13 John Ackermann N8UR <j...@febo.com> wrote: Reviving the conversation about superb voltage regulators, I am looking for one to run the

[time-nuts] ULN regulator with more current capability than LT3042?

Reviving the conversation about superb voltage regulators, I am looking for one to run the analog and PLL bits of a high performance frequency synthesizer chip. The current drain looks to be about 160-180 mA at 1.8 V, which is uncomfortably close to the limit for the LT3042 (200 mA). The

[time-nuts] PulsePuppy Status

For those who ordered a PulsePuppy oscillator carrier board from TAPR -- we quoted early February delivery so I wanted to give a quick update. The boards are in hand and the kits ready to go, except... USPS managed to lose the box of programmed PICs on its way from my house to the TAPR

Re: [time-nuts] Rakon HSO-14

Here's a link to data on an 8607-008. You may recognize the bottom plot from a recent posting. :-) But the ADEV and PN data at the top of the page is from the factory test data. The ADEV doesn't explicitly say so, but I strongly believe it's based on comparison with a "gold standard" 8607.

Re: [time-nuts] More on SiLabs 5340

On 01/29/2018 04:54 PM, Chris Caudle wrote: On Mon, January 29, 2018 2:38 pm, John Ackermann N8UR wrote: The close-in phase noise is quite amazing, but the floor is much worse than in free-run mode. That phase noise plot doesn't look quite right, what PLL bandwidth did you set? Sorry

Re: [time-nuts] More on SiLabs 5340

On Jan 29, 2018, 4:54 PM, at 4:54 PM, Chris Caudle <ch...@chriscaudle.org> wrote: >On Mon, January 29, 2018 2:38 pm, John Ackermann N8UR wrote: >> The close-in phase noise is quite amazing, but the floor is much >worse >> than in free-run mode. > >That phase noise

Re: [time-nuts] Si5340 synthesizer chip performance

>(415) 215-3779 > >> On Jan 28, 2018, at 4:23 PM, John Ackermann N8UR <j...@febo.com> >wrote: >> >> I received the Si5340A evaluation board from Digikey on Friday and >fired it up yesterday. I used the SiLabs "ClockBuilder" software to >configure fou

[time-nuts] Si5340 synthesizer chip performance

I received the Si5340A evaluation board from Digikey on Friday and fired it up yesterday. I used the SiLabs "ClockBuilder" software to configure four outputs -- 10 MHz, 15 MHz, 29.999 999 9 MHz, and 144.2 MHz -- all using the 45 MHz crystal that comes with the EVM. Attached is a phase noise

[time-nuts] TNS-BUF bare boards

Some time ago TAPR did a one-time run of a very low noise, very high isolation buffer amplifier. The assembled boards are sold out, but we had some extra blank boards made and finally (after a long story) got those delivered from Hungary to the office. If you're interested in a TNS-BUF

Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

pins as well. Just keeping your options open there. Bob L. Sent: Thursday, January 25, 2018 at 3:23 PM From: "John Ackermann N8UR" <j...@febo.com> To: time-nuts@febo.com Subject: Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block? Hi Bill -

Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

WB6BNQ John Ackermann N8UR wrote: Hi Bill -- I should have been more clear: this design will be for a simple case: one reference clock input, four outputs.  The chip can do all sorts of fancy tricks, but I'm looking for a source of four low jitter outputs derived from a 10 MHz external

Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

. Perhaps you could indicate what you are attempting to do with it and how you are going to accomplish your goals ? 73BillWB6BNQ John Ackermann N8UR wrote: After the recent discussion about Silicon Labs clock generators, I looked at their Si5340A part and think it will be useful

[time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

After the recent discussion about Silicon Labs clock generators, I looked at their Si5340A part and think it will be useful for a ham radio project I'm working on. While it can do other things, for my use it would use a 10 MHz input clock and generate 4 independent outputs in the range of 100

Re: [time-nuts] trimble Thunderbolt, how to get 25 or 27 mHz from it??

ansverters. It looks like the 5328 has two outputs, which is still useful but would require putting two or three of them on the board. Which isn't the end of the world. Thanks, John On 1/19/2018 8:56 AM, Mark Goldberg wrote: On Jan 19, 2018 6:01 AM, "John Ackermann N8UR" <j...@f

Re: [time-nuts] trimble Thunderbolt, how to get 25 or 27 mHz from it??

Sorry to hijack the thread, but the Si5351 looks interesting for another project I'm working on. I know it specifies "low jitter" but has anyone looked at the phase noise? Is it usable for RF applications? Thanks, John On 01/18/2018 08:53 AM, D. Jeff Dionne wrote: Chris, You don't

Re: [time-nuts] Stable32 now available

FWIW, for me the hardest part of working with Stable32 is getting the input scaling and other parameters like timestamps correct. If you think like a mathematician, you'll probably do fine. But I don't, and when working in particular with frequency data it always takes me a few tries to get

Re: [time-nuts] TAPR "PulsePuppy" Pot Selection

egard. > >Dana > >On Sun, Dec 24, 2017 at 9:58 AM, John Ackermann N8UR <j...@febo.com> >wrote: > >> I'm glad that the PulsePuppy post spawned some good discussion! >> >> The pot I'm using is a Bournes 3296W-1-103LF which is a 25-turn, 10K, >> cermet

Re: [time-nuts] TAPR "PulsePuppy" Pot Selection

I'm glad that the PulsePuppy post spawned some good discussion! The pot I'm using is a Bournes 3296W-1-103LF which is a 25-turn, 10K, cermet pot, spec'd at 100ppm/degree, so it's not anything super fancy. The number of turns provides decent setability, and it seems to be a good match for the

Re: [time-nuts] New product: the TAPR "PulsePuppy"

at everything you see in the ADEV plot is a >function of the >specific OCXO you put on the board. Put another way, the. board’s ADEV >is way >better than the ADEV of the OCXO. It’s a very safe bet that everything >past 2 seconds >or is the OCXO. > >Bob > >&g

Re: [time-nuts] New product: the TAPR "PulsePuppy"

Sorry, a typo got into the URL for the manual. Remove the extraneous "m" after ".pdf": http://www.tapr.org/~n8ur/PulsePuppy_Manual.pdf On 12/23/2017 04:00 PM, John Ackermann N8UR wrote: I've developed a little board called the PulsePuppy that supports surplus OCXOs in

[time-nuts] TICC counters available again

TAPR sold out the first run of TICC timestamping counters but we just took delivery of a second batch, and we're now taking orders. See http://tapr.org/kits_ticc for details. John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go

Re: [time-nuts] chrony vs ntpd

Jim, I thought about using an RF-input sync pulse for alignment during the Solar Eclipse measurement experiment, but ended up running out of time to implement it. But some very crude experiments indicated that it's not hard to generate an edge out of a PPS that creates a comb well past HF.

Re: [time-nuts] Distribution divider/amplifier for 10MHz GPSDO

On 10/23/2017 04:52 PM, Hal Murray wrote: But if any of the EXT REF are low-z inputs, that won't work so well. Unless there is only one. Then you can use it as the last one and you don't need the explicit terminator. Good point. ___ time-nuts

Re: [time-nuts] Distribution divider/amplifier for 10MHz GPSDO

To some extent, it depends on the load presented by each device. The "EXT REF" input on many pieces of test equipment is fairly high impedance (maybe 10k?) and you can drive several of those with a single output, putting a 50 ohm load at the end of the line to provide a reasonable

Re: [time-nuts] sine to square wave circuits - performance data?

The inductor in the T2-Mini is nothing special. On Oct 4, 2017, 12:57 PM, at 12:57 PM, Attila Kinali wrote: >On Wed, 4 Oct 2017 12:02:35 +1300 (NZDT) >Bruce Griffiths wrote: > >> I could measure the PN of the TAPR variant of the Wenzel circuit >> as

[time-nuts] First results of eclipse data recording

(This is more amplitude than frequency related, but thought it might be interesting to the group. If not, sorry for the intrusion.) I used three software defined radios to record just under 1 TB of data during the eclipse period from my cottage at Beaver Island, Michigan, over 8 hours from

Re: [time-nuts] Fwd: [hpsdr] SDR experiment for the solar eclipse

ld imagine. Alan G3NYK - Original Message ----- From: "John Ackermann N8UR" <j...@febo.com> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Thursday, August 03, 2017 8:10 PM Subject: [time-nuts] Fwd: [hpsdr] SDR experiment fo

[time-nuts] Fwd: [hpsdr] SDR experiment for the solar eclipse

This is a little off-topic, but thought some of the group might be interested... so please forgive the interruption. John Forwarded Message Subject: [hpsdr] SDR experiment for the solar eclipse Date: Thu, 3 Aug 2017 15:07:57 -0400 From: John Ackermann N8UR <j...@febo.

Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

For what it's worth, I use PowerPoles extensively -- I use them for all my 12V distribution on ham gear as well as time-nuts stuff. One great advantage of the genderless design is that you can use extension cables, breakout boxes, and other tools to solve lots of problems. But they do lack

Re: [time-nuts] poor-man's oven

We did this years ago on a 430 MHz data radio with an utterly uncompensated crystal that would drift through the passband.  After building our own for a while, we discovered that Yaesu had something even better available through their replacement parts shop -- a spring clip with PTC that

[time-nuts] Administrivia: febo.com SSL certificate

If your browser has been throwing security warnings or errors when you try to access the web server at febo.com (for example, the list archives), that problem should now be fixed. I was using an SSL certificate issued by StartSSL, a company that has sort of shot themselves in the foot due to

Re: [time-nuts] Re. DIY atomic "resonator"

I investigated police radar stuff a long time ago, and for a while had an old X band unit shaped just like a searchlight, with analog meter. What I learned then was that even on the newer units, the tuning fork was specified to provide an independent means to verify the accuracy of the unit in

Re: [time-nuts] The ultraAtomic clock for home

Is there any way to derive carrier phase from these chips?  Or to get raw modulation data that might make it usable as the front end to one of PaulS's de-PSKers? On Apr 7, 2017, 1:04 PM, at 1:04 PM, Tom Van Baak wrote: >> Very good catch it is *not* the cme8000 chip. Thats

Re: [time-nuts] ADEV query Timelab and TICC

I noticed with the TICC that the very high peak voltage on the 5061, 5065, etc. PPS causes trigger errors.  Putting a 50 ohm load at the TICC channel input helped a lot, or an attenuator might even be better. These HP units have a very short pulse width that peaks at something like 20v into a

Re: [time-nuts] ADEV query Timelab and TICC

I saw a similar higher-than-expected ADEV from another user who was measuring GPSDO PPS vs. 10 MHz from the same GPSDO.  Using a T2-Mini  from the 10 MHz yields the expected results. I suspect that the GPSDO PPS in that unit is derived from GPS PPS rather than the OCXO, and thus is noisier in

Re: [time-nuts] My TICC came in the mail yesterday

Hi Andrew -- There seems to be more than a little magic involved in getting sane three-corner measurements. I've gotten best results when the run is long enough to have many data points per tau, and also that results when you're noise limited tend to go imaginary. Finally, I think things

Re: [time-nuts] Trimble "UCCM" GPSDO adevs

This is very, very cool, Mark. I've been concerned for a long time that people take way too seriously what you properly call "bogo-ADEV" that's self-generated from the GPSDO. Integrating a counter that compares against an external source is a huge win. But I want to remind everyone that as

Re: [time-nuts] TTimelab question

I really like the setup that Mark is describing. As to TAPR's plans, we've found that enclosures are a challenge -- metalwork is pretty expensive unless you get significant volume, and in our niche market, that's hard to do. But I am hoping to find an inexpensive clamshell-type enclosure

[time-nuts] TICC shipments

Hi All -- The production batch of TICCs has arrived at TAPR and the first shipments to customers are going out today. It will probably take another few days to get them all sent -- there are nearly 100 units going out the door! As previously mentioned, the TICCs have been loaded with

[time-nuts] TICC update

Our contract manufacturer has started loading software and testing the TICC systems (and so far, they all work!), and should ship the production run to TAPR by the end of the week. We'll start shipping them to customers shortly after they arrive at the office. We still have units available

[time-nuts] What interrupts aging?

We know of OCXO that have been continuously running for years and have exceptional aging, supposedly as a result. What does it take to interrupt that? A momentary loss of power? The oven cooling down? Some long period of off-time? Or, once the oscillator has baked in will it return to that

[time-nuts] Dropbox is cool, but...

So I was clever and decided to log some PPS data to a folder within my "Dropbox" folder. Strange results followed... the whole system just bogged down, and even fairly slow serial data dropped characters. It turns out that the culprit was the Dropbox daemon continuously trying to sync the

[time-nuts] Autodesk Eagle -- maybe they're listening

Autodesk just sent a follow-up to my "new price model unacceptable" complaint a few days ago. It looks like they are going to upgrade the "Standard" subscription ($100/year) to support 4 layer boards up to 160 cm2, which I think matches the current standard version capabilities. Here's a

Re: [time-nuts] OT: Eagle PC CAD now Autodesk, $500/year

The .INF file seems just to be a text description, and the non-versioned .ext/.zip/.run file  file is a link to the file one with the version number.  So either one will get you the same installer, and the .INF file isn't needed. Sent from BlueMail ​ On Jan 21, 2017, 9:45 PM, at 9:45 PM,

[time-nuts] Plug -- source for soldering equipment

Since quite a few of the folks on the list love the smell of solder in the morning, I thought I'd pass along a supplier of new and refurbished soldering stuff that I've had really good luck with: Bruce Sander at EAE Sales -- https://www.eaesales.com/ in Grabill, Indiana. I encountered EAE a

Re: [time-nuts] TICC update?

⁣Hi Scott -- We received the first-unit sample a couple of weeks ago and it successfully passed all tests, so we gave the go-ahead to do the production build. We've also sent the Contract Manufacturer the final software versions to be loaded to the Arduino as well as a set of test oscillators

Re: [time-nuts] Tom's PICDiv?

Sorry, I missed the "complete unit" part... the TAPR products do require some soldering. The TADD-2 does have a case available if that helps. John On 1/5/2017 8:21 AM, John Ackermann N8UR wrote: Hi Bob -- TAPR has two boards that provide life support for Tom's PICDiv chips: T

Re: [time-nuts] Tom's PICDiv?

Hi Bob -- TAPR has two boards that provide life support for Tom's PICDiv chips: The "TADD-2" is a six-channel divider allowing each channel to have its rate independently set from a common source: https://www.tapr.org/kits_tadd-2.html The "T2-Mini" is a tiny board that provides a single

[time-nuts] Update on TNS-BUF and TICC projects

Happy New Year, Time-Nuts! TAPR received the production run of TNS-BUF boards, and the engineering sample of the TICC, from our contract manufacturer last week. Both boards are nicely built and work as intended. TNS-BUF boards will be shipping soon to those who ordered; some may already

Re: [time-nuts] 1PPS users?

For amateur use, PPS comparison requires less equipment and can be more accurate than trying to measure RF rates like 10 MHz. When comparing two PPS signals, phase slips are very infrequent so you can observe drift rate over minutes/hours/days with an oscilloscope or simple time interval

Re: [time-nuts] OT: ExpressPCB (cross-post from volts-nuts)

That points out a key difference in the PCB house pricing models: ExpressPCB and the Advanced Circuits $33 prototype are flat fee up to a size limit (for Advanced Circuits 4 x 6 inches) while others go by the square inch -- OSH Park is $5/in2 for three copies of two layer, and $10/in2 for

Re: [time-nuts] TICC Timestamping / Time Interval Counter -- Available to Order

- Subject: [time-nuts] New Timestamping / Time Interval Counter: the TICC Date: Wed, 23 Nov 2016 10:48:57 -0500 From: John Ackermann N8UR <j...@febo.com> Counters with resolution below 1 nanosecond are difficult. They require either outrageous clock speeds, or interpolat

Re: [time-nuts] Switching regulator replacement for 7805

On 12/04/2016 04:34 PM, jimlux wrote: Even for time-nuts, I suspect we're not looking to eke out the last percent of efficiency from 96% to 97%, or handle wildly varying loads, etc. Nor are we usually looking for absolute minimum parts cost. The little OCXO I used for testing goes from about

Re: [time-nuts] Switching regulator replacement for 7805

as the battery drains but my current solution is noisyand those 78xx chips waste far to much power. ) On Sun, Dec 4, 2016 at 10:50 AM, John Ackermann N8UR <j...@febo.com> wrote: I found a cute little switching regulator that's a drop-in replacement for an LM7805: http://www.ebay.com/itm/261243604

Re: [time-nuts] Switching regulator replacement for 7805

And Digikey does stock the Murata part, for about $4.30. Why I couldn't find it when searching their site for switching regulators, I don't know. John On 12/04/2016 02:39 PM, John Ackermann N8UR wrote: Thanks for that pointer! When I searched Digikey, I wasn't able to find anything

Re: [time-nuts] Switching regulator replacement for 7805

:50 PM, John Ackermann N8UR <j...@febo.com> wrote: I found a cute little switching regulator that's a drop-in replacement for an LM7805: http://www.ebay.com/itm/261243604047 I got a couple to play with, mainly to see how bad the noise would be. Here are spectrum analyzer and PN shots com

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

something really obvious (again)? Bob On Nov 27, 2016, at 10:04 AM, John Ackermann N8UR <j...@febo.com> wrote: Good guess. The 10 MHz reference drives all the logic on the board, and particularly the counter that maintains a local timescale in 100us increments; the TDC7200 interpolates b

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

Good guess. The 10 MHz reference drives all the logic on the board, and particularly the counter that maintains a local timescale in 100us increments; the TDC7200 interpolates between the 100us ticks to stamp incoming events on channel A and/or B with picosecond precision. The stamps on both

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

Hi Luciano -- Glad to hear that! The capability you asked for already exists (great minds think alike...) In timestamp mode, the TICC will output the stamps for each channel independently, measured against the common 10 MHz reference. So if both channels are active, you'll see a bunch of

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

e code, so that's the urgent goal. Thanks! John On 11/25/2016 03:26 AM, David wrote: John, In what language is the GUI written? I might be able to help on that, or other parts of the software, if someone else hasn't yet volunteered. Dave, WA8YWQ On 2016-11-24 06:43, John Ackermann

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

is typically about 13ps or so. Bruce On Thursday, November 24, 2016 09:43:54 AM John Ackermann N8UR wrote: Hi Anders -- Thanks, and thanks for the info on the 53230A. I have not used one of those myself but the data sheet lists 20ps single-shot. Also I should note that the TICC does not compete

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

been a more elegant approach if they had been available. John On 11/24/2016 02:49 AM, Andrew Rodland wrote: On Wed, Nov 23, 2016 at 10:48 AM, John Ackermann N8UR <j...@febo.com> wrote: The TICC is implemented as a two-channel timestamping counter. That means it can measure one or t

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

Hi Anders -- Thanks, and thanks for the info on the 53230A. I have not used one of those myself but the data sheet lists 20ps single-shot. Also I should note that the TICC does not compete with counters like the 53230A for high speed measurement, or frequency counting. It does far fewer

Re: [time-nuts] How phase stable is rg59 or alternate coax

Several years ago I measured the delay of about 80 feet of LMR400 feeding a GPS antenna, much of which was lying on a black shingle roof in the Georgia sun. I checked in early afternoon when the sun was beating, and in the wee hours of the morning, to get the greatest temperature delta. My

Re: [time-nuts] 53132 replacement fan

Thanks, all for the tips. Glad to know it's a standard size so there's plenty of choice. John On 11/21/2016 12:57 PM, jimlux wrote: On 11/21/16 6:39 AM, Charles Steinmetz wrote: Tom wrote: EFB0412MD Airflow 7.17 CFM 6300 RPM Noise 24 dBA FBK04F12U Same exact form factor. Air Flow

[time-nuts] 53132 replacement fan

Does anyone have a part number for the 53132 fan (or equivalent)? Mine is getting pretty noisy. Thanks! John ___ 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

Re: [time-nuts] I love the smell of tantalum in the morning

Either hot tweezers or a hot air rework station are the best/easiest ways to remove dead parts. But two fine-tip soldering irons will also work and are a lot cheaper. The idea is to heat both ends of the part at once, and when the solder flows, lift or flip the part off. Then, use some

[time-nuts] TNS-BUF Update

We had enough interest in the TNS-BUF isolation amplifier project to go ahead with a production run. Thanks! The order has been placed with our contract manufacturer in Hungary and we expect the boards to arrive at the TAPR office in Texas around January 1, plus or minus shipping and customs

Re: [time-nuts] Temp/Humidity control systems?

On 10/27/2016 11:06 AM, Poul-Henning Kamp wrote: This is why a lot of people in costal climates who ventilate their basement during summer "to dry out the basement" get the exact opposite result: The air outside is a lot wetter than on the inside. I learned this myself last summer. We have

Re: [time-nuts] Temp/Humidity control systems?

On 10/26/2016 1:00 PM, Richard (Rick) Karlquist wrote: On 10/26/2016 8:59 AM, John Ackermann N8UR wrote: I may have the opportunity to build a small "clock room" and am considering whether I could make it an environmentally controlled space. I'd like to learn about the options

Re: [time-nuts] Temp/Humidity control systems?

26/2016 12:09 PM, William H. Fite wrote: John, this is what I bought for the Orlando VA Medical Center when I was setting up the research lab there. Not cheap, though. 螺 https://www.thermalproductsolutions.com/products/walk-in-temperature-humidity-test-rooms On Wed, Oct 26, 2016 at 11:59 AM, John

[time-nuts] Temp/Humidity control systems?

I may have the opportunity to build a small "clock room" and am considering whether I could make it an environmentally controlled space. I'd like to learn about the options for doing this. The space would probably be 6x8 feet or so, in a basement with one outside wall. Can anyone point me

[time-nuts] Fwd: TNS-BUF High Isolation, Low Noise Buffer Amp Available

We've received enough orders to go ahead with production on the TNS-BUF, so here's your last chance to join the cool kids -- we'll take orders at http://tapr.org/kits_tns-buf through tomorrow, Oct. 20. John Forwarded Message Subject: [time-nuts] TNS-BUF High Isolation, Low

Re: [time-nuts] TNS-BUF High Isolation, Low Noise Buffer Amp Available

feedthrough. This is a buffer amp, not a distribution amp, so it's a single channel circuit, and high isolation was one of the key design criteria. John On 10/12/2016 09:08 AM, Chris Caudle wrote: On Wed, October 5, 2016 9:15 am, John Ackermann N8UR wrote: I've previously mentioned

[time-nuts] Fwd: TNS-BUF High Isolation, Low Noise Buffer Amp Available

Just a reminder that the deadline to order TNS-BUF isolation amps is next week -- October 20. John Forwarded Message Subject: [time-nuts] TNS-BUF High Isolation, Low Noise Buffer Amp Available Date: Wed, 5 Oct 2016 10:15:46 -0400 From: John Ackermann N8UR <j...@febo.

Re: [time-nuts] TNS-BUF High Isolation, Low Noise Buffer Amp Available

It's possible we may have some bare boards, but no guarantees at this point. On 10/5/2016 2:04 PM, Dan Rae wrote: For those of us who aren't scared of surface mount stuff, and maybe even prefer it, will there be any bare boards available? Dan - ac6ao

[time-nuts] TNS-BUF High Isolation, Low Noise Buffer Amp Available

I've previously mentioned a high performance buffer amplifier called the "TNS-BUF" that I built based on a design by Dr. Bruce Griffiths with further input from John Miles. Key numbers are: * Phase noise -140dBc/Hz at 1 Hertz offset, noise floor -175dBc/Hz. (PN plot attached) * Reverse

Re: [time-nuts] COTS cesium standard physics package life

I think there are two separate issues to consider: 1. Cesium depletion, which only occurs when the tube is operating with cesium oven on, and high voltage at the other end; and 2. Tube vacuum and other physical aspects that may deteriorate over time, whether or not the tube is operating.

Re: [time-nuts] 53132A triggering

at way, the triggering should be pretty solid. There is still > the wonderful stuff about pulses that > arrive on top of each other …. > > Bob > >> On Sep 16, 2016, at 1:10 PM, John Ackermann N8UR <j...@febo.com> wrote: >> >> I'm fairly new to driving the 5

[time-nuts] 53132A triggering

I'm fairly new to driving the 53132 and it seems to be quite a pain to set up reliable triggering for TTL-level pulses (e.g., PPS). Simply leaving it to auto-trigger sure doesn't do the trick. Any suggestions on optimum trigger settings for this use? Thanks!

Re: [time-nuts] GPS message jitter (was GPS for Nixie Clock)

Long ago I measured the impact of the linux low_latency flag on a 16550 UART. I don't know where that data is sitting now, but I remember that it made a significant difference. > On Jul 18, 2016, at 9:59 PM, Hal Murray wrote: > > > jim...@earthlink.net said: >>

Re: [time-nuts] Visiting Greenwich

I'm a bit of a crypto-geek and was able to visit Bletchley a couple of times, again many years ago. It is definitely worth a trip, though from what I saw on my visits and have read lately it has evolved badly. It used to be run on a shoestring with enthusiastic volunteers everywhere and lots

Re: [time-nuts] Visiting Greenwich

When I was there (10+ years ago) the timekeeping stuff was at the observatory, which is just a few minutes walk up from the NMM. Both sites are fascinating and well worth spending some time. I took a tour boat to get to Greenwich from central London -- it's the end of the line and if you work

Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping

You know, this thread has had a tremendous amount of practical information, with actual URLs, etc. Would someone be willing to consolidate the info on a web page somewhere? > On Jun 24, 2016, at 9:56 AM, Oz-in-DFW wrote: > > On 6/23/2016 10:53 PM, Chris Albertson wrote:

Re: [time-nuts] Measuring receiver...

I've seen references that at least by the latter part of WW2 oscillographs were being used to identify transmitters and/or ops. It should be possible to deduce chirp, rise time, fall time of signals, all of which characterize the transmitter, as well as element spacing and other

Re: [time-nuts] Goodie for British Timenuts!!!

Boy, that looks an awful lot like a re-branded Sulzer 5 with Sulzer power supply! > On Jun 7, 2016, at 1:38 PM, wrote: > > Hi, > > Saw this while trolling for goodies! > > http://www.mullardmagic.co.uk/racal-ma259-frequency-standard-ra17-ra117-r >

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