Re: [time-nuts] Brandywine GPS-4 OCXO

Hi Pictures probably would help :) Bob > On May 20, 2017, at 8:00 AM, Magnus Danielson > wrote: > > Hi, > > Does someone happen to know what OCXO sits in the Brandywine GPS-4 GPSDO? > It's pretty good sized OCXO, possibly double-oven. It has a screw on the side

Re: [time-nuts] Looking for info on Trimble 16634-10

Hi The mating side of that 22 pin connector isn’t going to be cheap. It looks like something out of their government systems group back in the late 90’s. If it is, you may have a hard time getting info on it. I’d pop it open and see what’s inside. At least that will give you an idea if it’s

Re: [time-nuts] Machining some aluminum help!

Hi > On May 19, 2017, at 5:35 PM, Chris Albertson > wrote: > > Yes, threaded inserts. There are many kinds but they are used almost > universally for cases where the material to be threaded is soft, like > aluminum. They also eliminate or reduce galvanic

Re: [time-nuts] Machining some aluminum help!

> On May 18, 2017, at 8:13 PM, jimlux wrote: > > On 5/18/17 2:36 PM, Chris Albertson wrote: >> It would be easy to re-design the job for cheaper machining.. Do you >> really need to tap the holes? You might use self taping screws. Id the >> would work then you can do

Re: [time-nuts] HP5061B Modulation Adjustment

Hi > On May 16, 2017, at 10:04 PM, Donald E. Pauly wrote: > > https://www.febo.com/pipermail/time-nuts/2017-May/105298.html > > We recently got our second HP5061B to lock after changing the beam > tube. We did no alignment with the exception of changing the gain on >

Re: [time-nuts] HP 1820-0313 4.2V Logic (Flip-flop)

Hi If you approach this as “restoring a classic car”, then you repair the beast. From a practical standpoint, looking at the schematic and what’s in the divider setup ….. it looks like a < $2 PIC or ($3 STM32 board ) would replace almost everything there. That’s not quite accurate, but it’s

Re: [time-nuts] Regarding the 00105-60xx (Bringing a 5065A back to life)

Hi If you do decide to go with the 105 OCXO’s in your 5065A, you probably will need to test the samples you have on hand. The selection process that sorted them into groups took place before many Time Nuts were born. Over that sort of time period, stuff drifts and (possibly) gets better. Even

Re: [time-nuts] HP10811 Oscillator Thermal Fuse

crowave instrument. > > πθ°μΩω±√·Γλ > WB0KVV > > -- Forwarded message -- > From: Bob kb8tq <kb...@n1k.org> > Date: Thu, May 11, 2017 at 4:28 PM > Subject: Re: [time-nuts] HP10811 Oscillator Thermal Fuse > To: Discussion of precise time and frequency measur

Re: [time-nuts] HP10811 Oscillator Thermal Fuse

Hi A bit in jest:… that compares to 3,957 incidences of open fuses that had nothing to do with a thermal runaway. Of those, the majority 3,721 resulted in the 10811 being tossed in the garbage as “another junker”……(yes, those are estimates, but I’d bet they are close based on the number of

Re: [time-nuts] TruePosition GPSDO performance

Hi The small OCXO in the TruePosition probably will do better with a beach towel tossed over the unit. It’s going to be pretty sensitive to drafts ….There are teardown pictures in the archives of the OCXO. Not much insulation in one of them at all. Bob > On May 11, 2017, at 4:06 PM, Mark

Re: [time-nuts] HP10811 Oscillator Thermal Fuse

ssage- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob > kb8tq > Sent: Thursday, May 11, 2017 6:25 AM > > > Ultimately it all came to no good. The energy conservation rules simply > took over. Shutting down everything during off hours became the way a

Re: [time-nuts] HP10811 Oscillator Thermal Fuse

Hi Ok, well since I was *asked* to say more :) Long ago heavy users of this sort of gear figured out that you wanted to keep the OCXO’s on all the time. That was the way to make the gear the most stable. That is the way you can use your counter / generator / whatever when you get to work in

Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

Hi Unless you believe that HP’s quality was poor, the experience of the rest of the OCXO business is likely relevant. In `~50 years of designing OCXO’s the only one I have ever seen are the HP units. Nobody else does that. Based on return rates, the number of “runaway ovens” is negligible

Re: [time-nuts] A good GPS-Receiver with 1PPS output...

Hi For the same money, you could get one of these: http://www.ebay.com/itm/152340314423?_trksid=p2057872.m2749.l2649=STRK%3AMEBIDX%3AIT Then locking up another oscillator is just a simple phase locked loop.

Re: [time-nuts] TruePosition GPS Receiver

Hi Often these guys use a “re-branded” driver for this or that. They then stop updating / supporting the driver. Theirs uses the same files as the “real” driver, but it is hopelessly out of date. You have seen the sort of issues this can cause …. Bob > On May 9, 2017, at 7:02 PM, Ben Hall

Re: [time-nuts] Counter Internal Oscillator Importance with External Reference?

Hi If you grab the schematic of pretty much any of these counters, you find a fairly common approach. Somewhere inside is a VHF oscillator. The internal TCXO, OCXO, or Rb acts as a phase lock source for that VHF oscillator. Typical PLL bandwidths are pretty low (10’s of Hz). When you put in

Re: [time-nuts] HP10811 Oscillator Thermal Fuse

Hi You will get a lot of diversity of opinion on the topic of the thermal fuse on the 10811. My feeling is that they are a nuisance and contribute very little to the design. I’d just short it out and move on. In the era of failure prone heater transistors or faulty thermistors, the fuse may

Re: [time-nuts] Using 5335 frequency counter for timing

HI Timing resolution of what we’re talking about: 53342 ns single shot. http://literature.cdn.keysight.com/litweb/pdf/5952-7900.pdf?id=172178:epsg:dow 53351 ns single shot

Re: [time-nuts] Using 5335 frequency counter for timing

Hi The 53131 and 53132 will get you more resolution. The TICC, the 5370, and the SR620 will do even better. None of them will do as well as a really fast scope. Bob > On May 7, 2017, at 8:52 PM, Jerry Hancock wrote: > > I was showing my son how we could measure the

Re: [time-nuts] HP5065A S/N 0048-00131 - Worth repairing (and how to do it)?

Hi ……. You have just discovered why we all depend on hard working Corby so much. Repairing these old beasts is not as easy as it first seems !! The traditional theory about mag wire on a metal tube was that they both have very similar temperature coefficients (maybe) and that there is no

Re: [time-nuts] TruePosition GPS Receiver

Hi Digging a bit more into this and that: The board in this writeup: http://www.qsl.net/wa2omy/A%20Packrat%20GPS%20Receiver%20Project.pdf Has 2005 firmware in it (6 years before our boards). It was built at the end of

Re: [time-nuts] TruePosition GPS Receiver

Hi The batch I just got in yesterday have a six pin connector on top labeled J2 and a 15 pin connector on the back labeled J1. There is no pin at location 14 on J1. There is an unpopulated location for a 10 pin J7 (looks like JTAG). There is also a set of holes in another 10 pin array labeled

Re: [time-nuts] How get FEI-Zyfer 380 GPSDO to talk with computer?

Hi I have a nasty suspicion that the “GPSMon" Zyfer is talking about is not the same program that is part of the Linux package. It’s a fairly obvious name. I’d bet it got re-used a couple of times. The docs on gpsd refer to it’s own tangled history in this regard. It’s certainly worth trying.

Re: [time-nuts] Three-cornered hat on timelab?

this incorrectly? > Bob > > - > AE6RV.com > > GFS GPSDO list: > groups.yahoo.com/neo/groups/GFS-GPSDOs/info > > > From: Bob kb8tq <kb...@n1k.org> > To: Bob Stewart <b...@evoria.net> > Cc: Discussion of precise time

Re: [time-nuts] Three-cornered hat on timelab?

t I should have asked is this: "how do I get that from a Timelab dataset?" > > Bob > > > From: Bob kb8tq <kb...@n1k.org> > To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency > measurement <time-nuts@febo.com> > Cc:

Re: [time-nuts] Three-cornered hat on timelab?

Hi RMS: https://en.wikipedia.org/wiki/Root_mean_square When we talk about things like “6 sigma” in QA, the sigma is the RMS. Bob > On May 3, 2017, at 1:44 AM, Bob Stewart wrote: > > Hi Tom, > Could you clarify the term RMS?

Re: [time-nuts] TAPR GPS kit end plate - final call

Hi Right now you are at 26 plates. There may be a price break at 25 there might be a break above that. It may be simpler to ask them where the breaks are (as in “please quote 25 to 100 pieces”) rather than going back and forth multiple times. If the price drops quickly with volume, the number

Re: [time-nuts] HP 3048A Phase Noise System needs a new home

Hi A suggestion for anybody heading over to grab this still very good phase noise test set - grab the “spare” 3561A. It tends to be the weak point in the setup. Bob > On May 1, 2017, at 7:14 PM, Dan Rae wrote: > > Basic system comprising: > > 3561A Analyzer > > 11848A

Re: [time-nuts] TruePosition GPS Receiver

Hi The Furuno receiver on the board is an older model. It’s similar to the M12’s. Not quite as sensitive as the “modern” stuff, but still very usable. Tough to beat the price … hint: the guy takes offers … hint hint Bob > On May 1, 2017, at 5:35 PM, Gregory Beat wrote: >

Re: [time-nuts] removing sidereal correlation

Hi A *lot* of the upload and estimate processes have changed over the years. What was true at "maybe every 2 hours" four years ago might be wrong today. Oddly enough it *could* be wrong in either direction. What they can’t change is the coarse resolution of the estimate. That’s embedded in

Re: [time-nuts] TAPR Oncore M12+ kit

awing of the plates? >> >> >> >>> On Apr 28, 2017, at 11:33 AM, jimlux <jim...@earthlink.net> wrote: >>> >>> On 4/28/17 10:09 AM, Bob kb8tq wrote: >>>> Hi >>>> >>>> If you go with the PCB approach, the nice thi

Re: [time-nuts] TAPR Oncore M12+ kit

n glue (using superglue) the stock down onto the scrap. I can then > machine around the edges without worrying about clamping. With pockets > though, the torque even when ramping down might break the part loose. > > How many plates are needed? > > >> On Apr 28, 2017,

Re: [time-nuts] TAPR Oncore M12+ kit

> > NB, I don't work for a fab house, nor have I ever toured one. > > Bob > > > > From: Bob kb8tq <kb...@n1k.org> > To: Discussion of precise time and frequency measurement <time-nuts@febo.com> > Sent: Friday, April 28, 2017 1:06 PM > Subject: Re:

Re: [time-nuts] TAPR Oncore M12+ kit

f shipping. > > Does anyone have a dimensioned print, picture, cad drawing of the plates? > > > >> On Apr 28, 2017, at 11:33 AM, jimlux <jim...@earthlink.net> wrote: >> >> On 4/28/17 10:09 AM, Bob kb8tq wrote: >>> Hi >>> >>> If

Re: [time-nuts] TAPR Oncore M12+ kit

Hi If you go with the PCB approach, the nice thing is getting stuff like the slot for the D connector done at the PCB fab. That way you have something that drops right in and works. The downside is that not every pcb house is happy doing that sort of “CNC work”. I have absolutely no idea why.

Re: [time-nuts] TAPR Oncore M12+ kit

Hi Another possible answer for end plates is to 3D print them. Doing it cheaply is not going to do you any good EMI wise (it’s plastic). It will keep dust and bugs out of the enclosure. Doing it with a metal loaded material is probably less than $7 an endplate, but not as good looking as

Re: [time-nuts] Three-cornered hat on timelab?

> will probably see anything less than that multiple times, with the probably >> increasing as the value gets lower. >> >> Not trying to crucify you with your own words, Bob. Like many of the >> time-nuts who don't post, I'm just trying to make some sense of th

Re: [time-nuts] Three-cornered hat on timelab?

> probably see anything less than that multiple times, with the probably > increasing as the value gets lower. > > Not trying to crucify you with your own words, Bob. Like many of the > time-nuts who don't post, I'm just trying to make some sense of this in terms > I can deal with. &g

Re: [time-nuts] Three-cornered hat on timelab?

Hi You have roughly 25 ns p-p in the data you show. There are a number of 10 ns “cycles” in the data. Any of this *may* be due to ionosphere. They also could be due to other issues. With ~4.4 days of noisy data, it may be tough to spot a trend. Since the ionosphere is a bit random, there is

Re: [time-nuts] Frequency counter questions

Hi Single mixer into a computing counter was the way this stuff was done for a *lot* of years. The sort of resolution you needed a fancy counter for back in 1969 is well within the F7 board’s capabilities. What you get for resolution is often less of an issue than the accuracy of the readings.

Re: [time-nuts] Frequency counter questions

Hi > On Apr 26, 2017, at 2:31 AM, Mark Sims wrote: > > If your frequencies of interest can be divided down to to the 1PPS range, > the TAPR TICC makes for an excellent frequency counter. The TADD-2 Mini > divider handles 1/2.5/5/10 Mhz or with a PIC chip swap 1/5/10/15

Re: [time-nuts] Frequency counter questions

Hi > On Apr 26, 2017, at 12:29 AM, Jerry Hancock wrote: > > Do typical frequency counters start their gate in phase with the incoming > signal? I guess the > answer would be, "It depends." I was just thinking about how I would program > the STM32F7 > counter I am

Re: [time-nuts] Frequency counter questions

Hi Keep in mind the previously stated limitation - Your GPSDO is only just so accurate. If you *could* read 0.001 Hz on a 100 MHz signal in a second, the GPSDO would not be anywhere near good enough as a reference. Keeping track of that sort of stuff is one reason a lot of companies train you

Re: [time-nuts] Frequency counter questions

Hi > On Apr 25, 2017, at 8:53 AM, jimlux <jim...@earthlink.net> wrote: > > On 4/25/17 4:42 AM, Bob kb8tq wrote: >> Hi >> >>> On Apr 25, 2017, at 1:24 AM, Orin Eman <orin.e...@gmail.com> wrote: >>> >>> On Mon, Apr 24, 20

Re: [time-nuts] Frequency counter questions

Hi > On Apr 25, 2017, at 1:24 AM, Orin Eman <orin.e...@gmail.com> wrote: > > On Mon, Apr 24, 2017 at 5:16 PM, Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> >>> On Apr 24, 2017, at 6:54 PM, Hal Murray <hmur...@megapathdsl.net> wrote

Re: [time-nuts] Frequency counter questions

Hi > On Apr 24, 2017, at 6:54 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> You have a “gate” from the GPSDO and a “signal” from somewhere else. If you >> want the STM to do the whole thing, the “gate” pin needs to get the job done >> in X +/- 1 cycles of the

Re: [time-nuts] Frequency counter questions

Hi I believe what you are going to find is that the 3586 has an IF strip in it. It does a heterodyne process to the IF center frequency and then indicates things from there. If the IF strip is out of alignment, you get a reading error. Probably worth digging into the service manual on the 3586.

Re: [time-nuts] Frequency counter questions

Hi > On Apr 24, 2017, at 3:49 PM, Chris Albertson <albertson.ch...@gmail.com> > wrote: > > On Mon, Apr 24, 2017 at 10:13 AM, Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> Some of the process below is “not trivial”. One example: >> >

Re: [time-nuts] Frequency counter questions

Hi One advantage of keeping this on list — There are 3586B Guru’s running around here. I’m sure one of them will hop in to explain a bit more about what’s going on inside that beast. Since (as you point out) you can put the same signal in as the reference, it may be as simple as cranking pot

Re: [time-nuts] Frequency counter questions

Hi Some of the process below is “not trivial”. One example: You have a “gate” from the GPSDO and a “signal” from somewhere else. If you want the STM to do the whole thing, the “gate” pin needs to get the job done in X +/- 1 cycles of the “signal” pin. Delay X (if it’s consistent) isn’t a

Re: [time-nuts] Frequency counter questions

Hi Let’s back off a bit. To most of us, a 12 digit counter displays 12 digits regardless of the frequency you put into it. That’s been the way good bench counters have done it since the early 1970’s. Typically the number of digits is specified at a one second gate time. An HP 5335 is one

Re: [time-nuts] Frequency counter questions

Hi > On Apr 23, 2017, at 2:43 PM, Chris Albertson <albertson.ch...@gmail.com> > wrote: > > On Sun, Apr 23, 2017 at 7:38 AM, Bob kb8tq <kb...@n1k.org> wrote: > >> >> >> If you want to do something like the 53131 or even the 5335, you will nee

Re: [time-nuts] Frequency counter questions

Hi > On Apr 23, 2017, at 12:43 PM, Richard Solomon wrote: > > At that resolution, you need a very accurate and stable Time Base. > > A GPSDO may not be good enough for 10 e12 measurements. > If buy some truly strange chance, this *is* a 100,000 second gate time exercise

Re: [time-nuts] Frequency counter questions

Hi Counting 12 digits is relatively easy, if that is the only constraint. Bring your “signal” into one of the timer clock inputs on the MCU. If your “signal” is 10 MHz that will be simple. If it’s 30 GHz it will be more difficult. 10 MHz gives you 7 digits a second. To get to 12 digits, you

Re: [time-nuts] Old NMEA GPS units with week rollover bug

Hi If you drive them with a simulator, essentially *all* GPS devices have the “rollover bug”. Put another way, take a LEA-(any)T. Cold start it. Feed it with a date ( = week number) 20 years past when it was made. It will go back and show you a date prior to today. Note - the cold start

Re: [time-nuts] Name of integral of timing residual

Hi On a normal GPSDO holdover spec, you are concerned with the maximum time error over a specified period. Generally it’s going to be a 24 hour holdover, but it can be longer or shorter depending on the application. The good old CDMA spec got out into the 10 to 11 us range at 24 hours. Various

Re: [time-nuts] Name of integral of timing residual

Hi Hi I think your “quest” to find the terms as they relate to motion is a pretty good example of just how unusual these terms are. Once you go past displacement, they are hardly common vocabulary. My guess is that nobody has ever come up with terms in the time domain that have made it into the

Re: [time-nuts] Measuring coax temperature coefficient with a TICC

Hi > On Apr 19, 2017, at 2:57 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> I’d want to be pretty sure what the center conductor was made out of. I’ve >> seen some stuff in coax that “one would think” should not be there (copper >> over steel …). > > Does that

Re: [time-nuts] Measuring coax temperature coefficient with a TICC

Hi One of the easiest ways to get a slow ramp it to toss the foam box full of cable out the back door. Assuming it stays in the shade, you can often get a pretty good 24 hour temperature cycle. You still need to monitor things to know what the ramp is. Generally it’s slow enough that you can

Re: [time-nuts] Measuring coax temperature coefficient with a TICC

Hi > On Apr 18, 2017, at 8:33 PM, jimlux <jim...@earthlink.net> wrote: > > On 4/18/17 3:55 PM, Bob kb8tq wrote: >> Hi >> >> On something like a 500’ spool of coax, the question will always be “what >> temperature is it where in the spool”. A sing

Re: [time-nuts] Measuring coax temperature coefficient with a TICC

Hi On something like a 500’ spool of coax, the question will always be “what temperature is it where in the spool”. A single sensor will only give you precise information if the temperature ramp is *very* slow (as in days …). Bob > On Apr 18, 2017, at 11:50 AM, Mark Sims

Re: [time-nuts] Three-cornered hat on timelab? -> GPS

Hi There are a number of survey grade receivers that pop up on eBay from time to time. They rarely have “timing” features like an external reference and PPS output that both work properly. There’s also a bit of risk buying them and finding out they are non-functional. All that said, if you

Re: [time-nuts] Three-cornered hat on timelab?

> [1] Fun GPS orbit stuff here: > http://leapsecond.com/pages/sidereal/index.htm > http://leapsecond.com/pages/sidereal/14years.htm > http://leapsecond.com/pages/sidereal/sv.htm > http://leapsecond.com/pages/gps-orbit/ > > > - Original Message - > From: "Bob Stew

Re: [time-nuts] Three-cornered hat on timelab?

<b...@evoria.net> wrote: > > Hi Bob, > > OK, thanks. I've kicked off a 7 day run of a GFS against the PRS-45A. That > should be long enough to separate out the GFS from the PRS' drift direction > from the ionosphere. > > Bob > > > > > > F

Re: [time-nuts] Three-cornered hat on timelab?

eric swings on my GFS unit that you > and Bruce and others have spoken about. This bothers me a lot. Could it be > my location here in Houston? Could it be the Ublox LEA-6T compared to the > much older Motorola in the KS? > > Bob > > > > From: Bob kb8tq <kb...@

Re: [time-nuts] Three-cornered hat on timelab?

34310-T) could you please share it with me? I'm looking for relative > peformance, not a definitive test. Of course if you also have one of a > 34310-T against the same standard, that would be great! > > Bob > > > > From: Bob kb8tq <kb...@n1k.org> > To: Bo

Re: [time-nuts] Three-cornered hat on timelab?

Hi There are a number of papers from the 70’s and 80’s digging into three corner hat data. The net result often would turn out to be “less than zero” noise on one of the DUT’s. Since that’s physically impossible the technique got a bit of “attention”. The Cliff Notes version of the results is

Re: [time-nuts] OCXO Soft-Start

Hi If your MCU has a POR that resets the internal oscillator that’s an unusual part. Most of them I’ve seen simply reset the CPU…..Once the 8 MHz crystal oscillator is running at 37 to 53 MHz (or KHz) it may or may not ever return to 8 MHz on it’s own. Yes, you need to get into some nutty

Re: [time-nuts] Mini-circuits ZFSC-8-1 a a reference distribution

Hi If the circulators are good to 10 MHz and you have eight of them to play with, then certainly they can be turned into isolators. Unless you have a really unique source of them, that kind of gets this out of the cheap seats. The “why” of isolation is very application dependent. Without

Re: [time-nuts] OCXO Soft-Start

supply is current or power limited the effective supply slew rate > is something like 1 mV/s, and under these conditions, at least this > particular unit starts up on B-mode every time. > > Running one of these on a USB supply (5V, 500mA = 2.5W) is looking > plausible. > > On Wed, Apr

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

nk.net> wrote: > > On 4/12/17 6:33 PM, Bob kb8tq wrote: >> Hi >> >> Back in the day (1960’s) noise diodes were quite a bit more expensive than >> they are today. Even >> today, a miniature lightbulb is quite a bit less expensive than a noise >> diode. Y

Re: [time-nuts] Mini-circuits ZFSC-8-1 a a reference distribution

Hi A lot depends on what you are trying to do. The disadvantage of power splitters is isolation. A dirt cheap logic IC based distribution amp will easily beat them in this regard. That said, the splitters are quite easy to find and hook up.They also are pretty much indestructible (at least I’ve

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

PM, jimlux <jim...@earthlink.net> wrote: > > On 4/12/17 1:23 PM, Bob kb8tq wrote: >> Hi >> >> >> *All* incandescent lamps emit RF ….. They are a resistive device that is >> heated to well above >> room temperature. People do use the

Re: [time-nuts] OCXO Soft-Start

Hi A SC cut crystal has multiple resonance “modes” in can operate on. This is in addition to the normal set of fundamental, third overtone, fifth overtone and so on. For various interesting reasons the SC modes are called A, B and C. On a normal 10 MHz crystal, the “main mode” is the C mode.

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

Hi There are papers from the mid 90’s talking about improving the GPS Rb’s. Those parts are as far as I know the best “production” Rb’s out there. The main comment seems to be that phase noise (in it’s various forms) is a major contributor to the stability of the Rb’s…. Bob > On Apr 12,

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

Hi *All* incandescent lamps emit RF ….. They are a resistive device that is heated to well above room temperature. People do use them in simple noise figure meters. The inductance of the filament in a typical bulb restricts the bandwidth a bit. The are designs from at least the 1960’s

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

Hi According to the data sheet the X version of the 2400 has a TCXO in it. The “not an X” has an XO. “Setability” of the XO is <0.5 ppm and the TCXO is rated at 0.2 ppm. Maximum resolution on the device occurs with a 20 MHz input. That gives you +/- 0.05 ppm. The 200 MHz range is scaled by 10

Re: [time-nuts] a link to a explanation of Rb vs Cs?

Hi If you take a look at the standard weekly publications, the GPS system runs on Rb’s. There is always one sat that has a Cs turned on. That’s been true as long as they have been running the system. The simple answer for that choice is that the Rb’s are easier to predict (better short term to

Re: [time-nuts] Re. DIY atomic "resonator" 6GHz synthesizer from ADI

Hi If you make the cells in the basement (or even in most factories) the ability to have a wide range synthesizer will come in handy. The whole “6.834xxx GHz” thing is dependent on a number of variables. It is not at all uncommon to produce cells that come out 10’s or 100’s of KHz off of the

Re: [time-nuts] a link to a explanation of Rb vs Cs?

HI > On Apr 11, 2017, at 5:57 PM, jimlux <jim...@earthlink.net> wrote: > > On 4/11/17 12:59 PM, Bob kb8tq wrote: >> Hi >> >> Assuming you are doing a “conventional” Rb and Cs there are a number of >> differences. There is the sub set of doing a gas

Re: [time-nuts] a link to a explanation of Rb vs Cs?

HI > On Apr 11, 2017, at 6:15 PM, Richard (Rick) Karlquist > wrote: > > The "magic" of Rb in a gas cell standard is that you > can make an optical filter cell out of radioactive > Rb87 isotope that allows you to selectively optically pump > to the quantum level you need.

Re: [time-nuts] a link to a explanation of Rb vs Cs?

Hi Assuming you are doing a “conventional” Rb and Cs there are a number of differences. There is the sub set of doing a gas cell based on Cs which is a lot more similar to Rb. With the Cs, you are building a very complicated vacuum tube that plays with a focused beam of ions traveling in

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

Hi If you are going to do a Rb, probably the best place to start is with a salvaged physics package out of one of the telecom Rb’s. That would let you get the “easy bits” worked out on your side of the design. It would also let you lear how to address a few of the more complex items sorted

Re: [time-nuts] TAPR TICC boxed (input protection)

;> On Apr 11, 2017, at 7:46 AM, Bob kb8tq <kb...@n1k.org> wrote: >> >> Hi >> >> >>> On Apr 11, 2017, at 7:05 AM, Charles Steinmetz <csteinm...@yandex.com> >>> wrote: >>> >>> David wrote: >>> >>>> I end

Re: [time-nuts] TAPR TICC boxed (input protection)

Hi Testing can mean a lot of different things. Did they test every single part they shipped for every parameter? Did they just do a sample of parts and decide the lot was good? Did they test a sample of parts for a sub-set of the specs and decide they were good? Did they test them after

Re: [time-nuts] TAPR TICC boxed (input protection)

Hi > On Apr 11, 2017, at 7:05 AM, Charles Steinmetz wrote: > > David wrote: > >> I ended up qualifying 2N3904s based on manufacturer and lot and I >> think we ended up using ones from Motorola. I wish detailed process >> information like National had was available from

Re: [time-nuts] TAPR TICC boxed (input protection)

Hi If anybody gets into this sort of thing in the future — There are black / optical blocking die coat materials out there. They are silicone based and quite stable. We used a *lot* of the stuff on watch modules after it was discovered that the watch died when exposed to a heavy dose of

Re: [time-nuts] Car Clock drift - the lowly 32kHz tuning fork crystal specs

Hi > On Apr 9, 2017, at 10:01 PM, Alex Pummer wrote: > > actually it does not compensate for temperature it is just for reduce the > production cost for the crystal. We --Jean Hoerni [founder of intersil, > Eurosil and one of the traitors who started Fairchild

Re: [time-nuts] Sinlge ADC multi-band receiver

Hi > On Apr 10, 2017, at 1:00 AM, Magnus Danielson > wrote: > > God Morgon Attila, > > On 04/09/2017 10:28 PM, Attila Kinali wrote: >> On Tue, 4 Apr 2017 17:58:11 -0700 >> jimlux wrote: >> >> The beauty of the system would be that you don't

Re: [time-nuts] Sinlge ADC multi-band receiver

> On Apr 9, 2017, at 4:29 PM, Attila Kinali <att...@kinali.ch> wrote: > > On Wed, 5 Apr 2017 08:27:58 -0400 > Bob kb8tq <kb...@n1k.org> wrote: > >> Galileo E5 is a bit of a strange case. It’s really E5a and E5b. >> You can either grab it all as one

Re: [time-nuts] Sinlge ADC multi-band receiver

HI > On Apr 9, 2017, at 4:28 PM, Attila Kinali wrote: > > On Tue, 4 Apr 2017 17:58:11 -0700 > jimlux wrote: > >>> The advantage of such a system would be that there is only a single >>> path through the system for all signals, especially through the

Re: [time-nuts] HP 100D FS [WAS: HP 105D FS]

HI If you take a look at the schematic of the oscillator circuit shown in the HP Journal article, it is the standard circuit that is used in just about every microprocessor clock and clock oscillator made (except for the vacuum tube …) No, it’s not the earliest example, but it is pretty early by

Re: [time-nuts] Car Clock drift - the lowly 32kHz tuning fork crystal specs

Hi The compensation process either for a clock or a watch has been embedded in the IC for a lot of years now. They do a pulse add / pulse drop approach to “level out” the 1 pps drive to the display. Temperature does not move fast enough that averaging things over a minute is an issue. That gives

Re: [time-nuts] HP 100D FS [WAS: HP 105D FS]

Hi The “heated crystal” approach was pretty common up until the 1970’s. Both GR and HP moved over to "electronics in the oven” at about the same time(early 60’s) for rack mount standards. There are a few tube based OCXO’s with heated electronics. Some of them date to the 1960’s others appear

Re: [time-nuts] Car Clock drift - the lowly 32kHz tuning fork crystal specs

Hi > On Apr 9, 2017, at 11:36 AM, Clint Jay wrote: > > The clocks in my car have been set by the RDS data, DAB data or GPS in the > last five or six I've had. Drift is a thing of the past as long as i listen > to digital radio or the BBC on analogue FM, if i listen to

Re: [time-nuts] HP 105D FS

d.. > > Sorry for the brain fart. > > Regards, > > Perrier > > > On Sunday, April 9, 2017 5:18 AM, Bob kb8tq <kb...@n1k.org> wrote: > > > Hi > > Are you sure you have the model number right? That does not sound like a 105D > … The 105B was a 1960’s

Re: [time-nuts] Car Clock drift - the lowly 32kHz tuning fork crystal specs

Hi In my “test environment” car clocks always run fast. That’s been true for many decades over many manufacturers. The idea of putting in an offset on a timekeeping device is an old one. You run the beast over the “expected” temperature (and other environmental) range. You observe how fast or

Re: [time-nuts] HP 105D FS

Hi Are you sure you have the model number right? That does not sound like a 105D … The 105B was a 1960’s creature that had a 5 MHz crystal in it already. Bob (who probably has eight typos in the sentence above :) > On Apr 9, 2017, at 2:46 AM, Perry Sandeen via time-nuts

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

Hi > On Apr 7, 2017, at 10:10 PM, Charles Steinmetz wrote: > > Jim wrote: > >> Charles wrote: > >>> [blob over wire bond construction] >>> is also extremely unreliable, particularly WRT environmental effects >>> such as temperature changes, humidity, and atmospheric

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

Hi > On Apr 7, 2017, at 7:19 PM, jimlux wrote: > > On 4/7/17 3:45 PM, Charles Steinmetz wrote: >> Bob wrote: >> >>> The epoxy over wire bond construction approach >>> is low cost, and not very experimenter friendly. >> >> It is also extremely unreliable, particularly WRT

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