Re: [time-nuts] Rubidium freq standard - temperature

je...@hanler.com said: > I tried scoping some pins. I see a few different levels and one pin has > what looks like a clock signal with a period of about 4.2ms. Other than > that, hard to tell without a manual. Some devices print out version info and such at power up. If you are willing to pow

Re: [time-nuts] Rubidium freq standard - temperature

Mark, I agree. I tried scoping some pins. I see a few different levels and one pin has what looks like a clock signal with a period of about 4.2ms. Other than that, hard to tell without a manual. I know people went so far as to contact Perkin Elmer without luck, I had heard they had acquired

[time-nuts] Rubidium freq standard - temperature

I doubt that it would be a direct mapping to a 9-pin serial connector. And probably would not be outputting anything unless prompted. It might be useful to scope the pins and see if anything looks like serial data. Even if it has a serial port, without some kind of manual, it is probably usel

Re: [time-nuts] Rubidium freq standard - temperature

I opened it up, JT1 has 9 pins. What are the odds? I think I have to hook something up to it and see if there is anything on 2 or 3, no? > On Nov 30, 2017, at 7:35 PM, Jerry Hancock wrote: > > I see a jack labeled JT1. It has about 8 pins I remember. I wonder... > > >> On Nov 30, 2017, at 7

Re: [time-nuts] Rubidium freq standard - temperature

I see a jack labeled JT1. It has about 8 pins I remember. I wonder... > On Nov 30, 2017, at 7:11 PM, Mark Sims wrote: > > A lot Rb's from that era have TTL level serial interfaces that can drive most > RS-232 ports directly. The PRS-10, SRO100, and LPFRS are examples. >

[time-nuts] Rubidium freq standard - temperature

A lot Rb's from that era have TTL level serial interfaces that can drive most RS-232 ports directly. The PRS-10, SRO100, and LPFRS are examples. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/

Re: [time-nuts] Rubidium freq standard - temperature

Will forward tomorrow. Yes I recall my lamp voltage is also very good. On Thu, Nov 30, 2017 at 8:41 PM, Jerry Hancock wrote: > Paul, send whatever you have to clist at hanler > (without the D) dot com > > Also, the caps we replaced were only 4 electrolytics. 3 x 470uf

Re: [time-nuts] Rubidium freq standard - temperature

Paul, send whatever you have to clist at hanler (without the D) dot com Also, the caps we replaced were only 4 electrolytics. 3 x 470uf 25v and a 270uf at 16V. I used a 330uf 25v for the later. I’ve seen them for like $30 Canadian. I think they are inexpensive due t

Re: [time-nuts] Rubidium freq standard - temperature

1) Model number is TS-RFS and they vary for series from A to H, assuming the series is linear as I only have 5 of them. 2) No manual. 3) There is an 8 bit dip switch with a maximum range of about 10mhz and a step of .39mhz. I might have these off by a factor of 10 but I was able to set two of mi

Re: [time-nuts] Rubidium freq standard - temperature

Jerry I have some dribs and drabs of details on the units I have. Happy to send whatever I have to you directly. Suspect its to large for FEBO. What I can tell is they must have been considered quite good and for military use. I haven't run mine alot because I was concerned about the temp like you.

Re: [time-nuts] Trimble Mini-T Timing Glitches

On 11/30/17 3:05 PM, Leo Bodnar wrote: Completely off-topic comment while on the subject: I can't see how randomly selected 1ms of data can contain unambiguously detectable start of C/A code. If NAV data bit phase flip occurred within this 1ms of data then correlation search will most probably

Re: [time-nuts] Rubidium freq standard - temperature

Paul, The units Gilbert gave me were TS-RFS. They are fairly large. The physics end is about 5”x2”x2" and overall length about 9”. They lock pretty quickly now that I’ve replace the caps. They can drive 50ohms pretty hard, outputting a square wave. I’m thinking of bolting on some fins to th

Re: [time-nuts] Trimble Mini-T Timing Glitches

On 11/30/17 1:31 PM, Leo Bodnar wrote: Bob, this is quite an unorthodox description of how GPS works. You probably want to rephrase that before it gets ripped to shreds. Leo From: Bob kb8tq GPS extracts time and location by locking on to various codes in the transmissions. One of them happen

[time-nuts] Rubidium freq standard - temperature

43C seems reasonable for the baseplate temperature. What is the model number for these? Do you have a manual? How are you setting the frequency?I just got in a Spectratime SRO100 and am adding support for it to Lady Heather. I may also do the LPFRS which may be related to yours. _

Re: [time-nuts] Trimble Mini-T Timing Glitches

On Thu, 30 Nov 2017 21:31:54 + Leo Bodnar wrote: > From: Bob kb8tq > > GPS extracts time and location by locking on to various codes in the > > transmissions. > > One of them happens to run at about a 1 KHz clock rate. A slip on that part > > of the > > process gives you a (modulo) 1 ms

Re: [time-nuts] Rubidium freq standard - temperature

Jerry You have some EG&G RBs. Thats great news. Now I am not alone. I have 2 also that work. I have found little details on them. That said I believe they are intended to be mounted on a heat sink. One end surely looks like that whats would be done. I believe mine are LCR-10-T. Might have to double

[time-nuts] Rubidium freq standard - temperature

I was able to get all 5 of these EG&G Rubidium Frequency Standards running by replacing the caps as another member found. They have a large heatsink on them, no fins, and are running at 43C. Is that too hot? Should I bolt them down to a larger heatsink? They consume a little over 9w after th

Re: [time-nuts] Trimble Mini-T Timing Glitches

Completely off-topic comment while on the subject: I can't see how randomly selected 1ms of data can contain unambiguously detectable start of C/A code. If NAV data bit phase flip occurred within this 1ms of data then correlation search will most probably fail. Yes, the probability of this is on

Re: [time-nuts] Trimble Mini-T Timing Glitches

Leo, About GPS and 1 ms... 1) Bob's version: Bob's succinct description is fine. There is often a 1 ms loop in GPS receiver firmware (you can see this in the spec for some timing receivers). It is not impossible that off-by-1 errors would occur at this level. 2) Book version: > Fundamentals

Re: [time-nuts] Trimble Mini-T Timing Glitches

Hi I’d freely admit it is *very* much the “Cliff notes” version of what is happening. Bob > On Nov 30, 2017, at 4:31 PM, Leo Bodnar wrote: > > Bob, this is quite an unorthodox description of how GPS works. > You probably want to rephrase that before it gets ripped to shreds. > Leo > > From:

Re: [time-nuts] Trimble Mini-T Timing Glitches

Bob, this is quite an unorthodox description of how GPS works. You probably want to rephrase that before it gets ripped to shreds. Leo From: Bob kb8tq >GPS extracts time and location by locking on to various codes in the >transmissions. One of them happens to run at about a 1 KHz clock rate. A

Re: [time-nuts] Trimble Mini-T Timing Glitches

Hi GPS extracts time and location by locking on to various codes in the transmissions. One of them happens to run at about a 1 KHz clock rate. A slip on that part of the process gives you a (modulo) 1 ms clock jump. Certain types of interference may “help” the receiver make these sorts of mist

Re: [time-nuts] Trimble Mini-T Timing Glitches

Historical: Ancient (as in Trimble SVeeSix - 20 or more years ago) Trimble GPS units would have their PPS timing output offset by several milliseconds when they lost a sufficient number of satellites to maintain a 4D solution. The PPS offset would jump back and forth by a large step (I recall six

[time-nuts] Trimble Mini-T Timing Glitches

Hello everyone, I have heard reports of Trimble Mini-T timing glitches with offsets of 1ms lasting for about 30 seconds several times during the past week. Some of the dates and times reported are at various locations include: 23/11/2017, approx 11:00 UTC 29/11/2017, approx 11:00 UTC 30/11/201

Re: [time-nuts] Performance verification for time counters

In message <20171130181024.832c6adfd3cea0658ba43...@kinali.ch>, Attila Kinali w rites: >What puzzles me here is, the reason why someone would care >about sub-1Hz frequencies in a telephone system? IIRC POTS >did cut off somewhere areound 100-300Hz anyways. They did not. Most carrier fre

Re: [time-nuts] Performance verification for time counters

Hi They aren’t looking at voice signals, they are looking at the distribution of timing signals. The filters cut off well below voice frequencies. The issue (as originally mentioned) is peaking in very long chains of repeaters. Since the cutoff can be *very* low (just like with a GPSDO), the freq

Re: [time-nuts] Performance verification for time counters

On Thu, 30 Nov 2017 09:39:59 -0500 Bob kb8tq wrote: > That last decade ( 0.01 Hz period to 0.001 Hz) What puzzles me here is, the reason why someone would care about sub-1Hz frequencies in a telephone system? IIRC POTS did cut off somewhere areound 100-300Hz anyways. At

Re: [time-nuts] ergodicity vs 1/f

Hi > On Nov 30, 2017, at 11:10 AM, Magnus Danielson > wrote: > > > > On 11/30/2017 03:40 PM, Attila Kinali wrote: >> On Thu, 30 Nov 2017 12:44:13 +0100 >> Mattia Rizzi wrote: >>> Let me emphasize your sentence: "you will have a statistically significant >>> number of samples of *one* realiz

Re: [time-nuts] ergodicity vs 1/f

On 11/30/2017 03:40 PM, Attila Kinali wrote: On Thu, 30 Nov 2017 12:44:13 +0100 Mattia Rizzi wrote: Let me emphasize your sentence: "you will have a statistically significant number of samples of *one* realization of the random variable.". This sentence is the meaning of ergodic process [ h

[time-nuts] ergodicity vs 1/f (was: Allan variance by sine-wave fitting)

On Thu, 30 Nov 2017 12:44:13 +0100 Mattia Rizzi wrote: > Let me emphasize your sentence: "you will have a statistically significant > number of samples of *one* realization of the random variable.". > This sentence is the meaning of ergodic process [ > https://en.wikipedia.org/wiki/Ergodic_proce

Re: [time-nuts] Performance verification for time counters

Hi Sweep the transfer function from 100 Hz down to 0.001 Hz at 50 points per decade. Spend enough time at each point to get to 0.001 db sort of accuracy. The first decade goes pretty fast. That last decade ( 0.01 Hz period to 0.001 Hz) …. not so much. The request always has both the silly frequ

Re: [time-nuts] Performance verification for time counters

Thank you for great suggestions, I will try to set something up next week involving detuned clock or sinewave source. Leo ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and

Re: [time-nuts] Allan variance by sine-wave fitting

Hi, @All >True that the models depend on the noise statistics to be iid, that is ergodic. That's the first assumption, and, while making the math tractable, is the worst assumption. I am not talking about intractable math. I'm talking about experimental hypothesis vs theory. I said that if you fo

Re: [time-nuts] Performance verification for time counters

In message <42a2f881-1631-402c-8ed6-2c863f6fe...@n1k.org>, Bob kb8tq writes: >>> Needless to say *demonstrating* this 0.001 db sort of gain flatness on a >>> repeater >>> out to crazy low frequencies is a bit involved. It *is* a great gig if you >>> happen to be >>> a consultant … >> >>