Re: [time-nuts] Looking for ECL divide by 3 with symmetry
e...@telight.com said: > I need to build an ECL divide by 3 circuit to run at about 50 MHz input. I > know there are lots of examples out there, but I vaguely recall years ago I > stumbled upon one or more that also provided more of a symmetrical output > nearly 50 percent duty factor, by using both input edges, or reclocking > with another FF. If you you have a square wave input, you can build a clock doubler with an XOR and FF. That gives short pulses, but they are wide enough to clock FFs using that technology. You can add a delay line to make the pulse wider. (PCB traces are 6 inches per ns so you can get short delays that way.) If you are working with ECL, many parts use differential clocking so you can cleanly clock on the other edge by swapping pins. So you could make a 50-50 divide by 3 from 3 FFs: 2 for a count-to-3 FSM, and 1 clocked on the other edge, and a small cloud of gates. The FSM has 3 states. FF 1 is on for cycle 1. FF 2 is on for cycle 2. Both are off for cycle 3. FF 3 is FF 1 delayed by a 1/2 cycle. The output is FF 1 ORed with FF 3. I think the input to FF 1 is not (FF 1 or FF 2) The input to FF 2 is FF 1. The input to FF 3 is FF 1. -- These are my opinions. I hate spam. ___ 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 instructions there.
Re: [time-nuts] TimeLab and the N cornered hat...?
> On Sep 27, 2015, at 5:06 PM, John Miles wrote: > > If you're only loading two files, that's definitely not going to work since a > 3-cornered hat requires 3 plots. In your example, there must be a third plot > representing A-C, so that each of the three sources will contribute to two > different plots. Ok, well, that’s definitely what I missed. I faked it loading one of the files twice and labeling as you said - ab, ac and bc and it worked. Now to actually collect the correct data. Thanks! ___ 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 instructions there.
Re: [time-nuts] Looking for ECL divide by 3 with symmetry
Division by an odd factor requires clocking off both edges of the incoming clock if you wish to achieve a 50% duty cycle output. So the output duty cycle is affected by the duty cycle and response to the possibly different risetime and falltime of the incoming clock. I would think that for the best immunity from these effects you would need to use a differential amplifier to get clean rising edges from both incoming edges. But this may be too much detail ... see the following link for some examples of how to divide by odd numbers: http://www.onsemi.com/pub_link/Collateral/AND8001-D.PDF -- Bill Byrom N5BB On Sun, Sep 27, 2015, at 11:36 AM, ed breya wrote: > I need to build an ECL divide by 3 circuit to run at about 50 MHz input. > I know there are lots of examples out there, but I vaguely recall years > ago I stumbled upon one or more that also provided more of a symmetrical > output nearly 50 percent duty factor, by using both input edges, or > reclocking with another FF. I saved the info, but of course can't find > it now that I need it - in my computers, papers, or online. Does anyone > know of these tricks, and any example circuits - this would save me some > rediscovery and design time. > > Ed > _ > 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 instructions there. ___ 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 instructions there.
Re: [time-nuts] Looking for ECL divide by 3 with symmetry
IIRC one would use a divide by 4 circuit with the final output feeding back to an exclusive-or gate through which the (square wave) source clock passes. The ex-or effectively adds a clock edge to the divide by four, making it divide by three. It also changes the effective clock edge, so the final output is basically a square wave. http://www.theremin.us/Circuit_Library/symmetrical_digital_dividers.html Bob LaJeunesse > Sent: Sunday, September 27, 2015 at 12:36 PM > From: "ed breya" > To: time-nuts@febo.com > Subject: [time-nuts] Looking for ECL divide by 3 with symmetry > > I need to build an ECL divide by 3 circuit to run at about 50 MHz input. > I know there are lots of examples out there, but I vaguely recall years > ago I stumbled upon one or more that also provided more of a symmetrical > output nearly 50 percent duty factor, by using both input edges, or > reclocking with another FF. I saved the info, but of course can't find > it now that I need it - in my computers, papers, or online. Does anyone > know of these tricks, and any example circuits - this would save me some > rediscovery and design time. > > Ed > ___ > 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 instructions there. > ___ 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 instructions there.
Re: [time-nuts] TimeLab and the N cornered hat...?
If you're only loading two files, that's definitely not going to work since a 3-cornered hat requires 3 plots. In your example, there must be a third plot representing A-C, so that each of the three sources will contribute to two different plots. Apart from that, check for mismatched file parameters. The way it's currently set up, all of the following conditions have to be met before Trace->Show separated variances (Ctrl-h) will work: - A deviation measurement must be selected (ADEV, MDEV, TDEV, HDEV) - Overlay mode must be enabled with Display->Overlay (o) - At least three plots must be loaded - All participating plots need to have visibility turned on (Display->Toggle visibility (v)) - All participating plots must have valid Source A and Source B labels - The source labels must be spelled consistently between all of the participating plots - All participating plots need to have trace history set to 1 (Edit->Trace properties (e)->Trace History) - All participating plots need to have been acquired with the same xDEV bin density - All participating plots need to have exactly the same sample interval (tau zero) The last condition is especially easy to miss if your plots came from a counter with "Use incoming data to configure measurement" checked. It may have measured the sampling interval a bit differently in one or more of the plots. If you've already checked these points and it still isn't rendering the hat traces, zip up the .tim files and send them to john (at) miles.io, and I'll have a look. -- john, KE5FX Miles Design LLC > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Nick Sayer > via time-nuts > Sent: Sunday, September 27, 2015 8:25 AM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] TimeLab and the N cornered hat...? > > I’m running the latest beta, and I’ve found the spot in Edit > Trace details > where > you tell it the two sources that contribute to a particular dataset. I’d > expect that > having done that and loaded two traces A-B and B-C that I’d be able to elect > to > show the N cornered hat and see something different in the ADEV window, but > it’s not doing anything. What am I missing? > ___ > 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 instructions there. ___ 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 instructions there.
Re: [time-nuts] Looking for ECL divide by 3 with symmetry
I have rediscovered what I need, so no problem anymore. Ed ___ 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 instructions there.
Re: [time-nuts] FS: Distribution amps
Both HP5087's have been sold. -Brian, WA1ZMS iPhone > On Sep 27, 2015, at 2:19 PM, "Brian, WA1ZMS" wrote: > > Hi all- > > Time to clean out some extra items. > > I have one SRS FS710. Tested & works. Time-nuts price $150 + shipping to US > address. > I have two HP5087A dist. amps. Each one optioned a bit different. Tested & > work. $75/each + shipping to US address. > Also have one Austron 2100F. Make offer! > > Contact *off-list* if interested. > > Thanks, > -Brian, WA1ZMS > > > ___ > 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 instructions there. ___ 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 instructions there.
[time-nuts] Looking for ECL divide by 3 with symmetry
I need to build an ECL divide by 3 circuit to run at about 50 MHz input. I know there are lots of examples out there, but I vaguely recall years ago I stumbled upon one or more that also provided more of a symmetrical output nearly 50 percent duty factor, by using both input edges, or reclocking with another FF. I saved the info, but of course can't find it now that I need it - in my computers, papers, or online. Does anyone know of these tricks, and any example circuits - this would save me some rediscovery and design time. Ed ___ 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 instructions there.
Re: [time-nuts] More HP5065 experiments
Hi Poul-Henning, According to your linked info I understand that you don't have schematics and more info about the 105 OCXO. The HP 105 and HP 5065A don't include any information, treating it as a module that is not field reparable, but the HP 5061A Cesium Frequency Standard manual, while stating the same, does include this info both in theory of operation and schematics. If you don't have this manual at hand I can send you these info from mine. Regards, Ignacio EB4APL El 27/09/2015 a las 9:46, Poul-Henning Kamp escribió: Discovery of the day: The voltage supplied to the Rb87 lamp changes the frequency on the order of 1.5e-11 per volt. I have no idea why... http://phk.freebsd.dk/hacks/HP5065A/index.html ___ 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 instructions there.
[time-nuts] FS: Distribution amps
Hi all- Time to clean out some extra items. I have one SRS FS710. Tested & works. Time-nuts price $150 + shipping to US address. I have two HP5087A dist. amps. Each one optioned a bit different. Tested & work. $75/each + shipping to US address. Also have one Austron 2100F. Make offer! Contact *off-list* if interested. Thanks, -Brian, WA1ZMS ___ 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 instructions there.
[time-nuts] TASS Computer-Controlled Switch System
Every so often, I hijack the list to do some shameless self-promotion when I think it would be of interest to the 'nuts community. I've spent the last several months developing a computer-controlled relay switch system. The impetus was failure of the old HP 59307A GPIB switches in my PPS measurement system and discovery that replacement relays are unobtainium. The only similar remote switches I could find cost >$1K, which seemed a bit rich. So, I decided to roll my own. We ended up with an 8 port switch board controlled by an Arduino. I think it will have lots of T&F applications as well as usefulness in ham shacks. Like virtually everything I do, it ended up as a TAPR kit. There's an introductory video at https://youtu.be/P-TUM2dOi4c The relay board kit is $119 and we have a shield for the Arduino Mega 2560 that can control 4 relay boards and costs $19. The software is open source.The boards are now available from TAPR at http://tapr.org/kits_tass.html (BTW, I contribute my designs to TAPR and don't have any financial interest in sales.) Special thanks to time-nuts Bob Camp and Tom Holmes for a lot of engineering assistance. Here's the TAPR product announcement: " Now Available: The TASS Computer-Controlled Switch System The TASS (Totally Awesome Switch System) is a general purpose 8 port DC-150 MHz relay-based switch. The hardware is designed to be very generic, with an inexpensive processor such as an Arduino providing the system logic. Control is via USB, with ethernet and other interfaces also available. The TASS can be configured several ways, and multiple boards can be combined to create large switching systems. The TASS has many uses, from switching signal sources on a test bench or in a laboratory, to selecting receive antennas and filters in a ham or SWL station. The TASS system has two boards: * The TASS-R relay board, which does the mechanics of signal switching and provides a very simple 10-pin interface. * The TASS-SHIELD board for use with an Arduino Mega 2560 microcontroller. The TASS-SHIELD allows up to four TASS-R boards to be controlled simultaneously. Both boards are available now from TAPR as kits. They use through-hole parts and don't require any special assembly techniques. The final component is open source software for the Arduino that acts as an interface between a host computer or other input system, and the switching hardware. The software is available for download from TAPR. An introductory video is available at https://youtu.be/P-TUM2dOi4c or from TAPR at http://tapr.org/~n8ur/TASS/TASS_Intro_26Sep15.mp4 Software and documentation can be downloaded from http://tapr.org/~n8ur/TASS. You may order the TASS-R and TASS-SHIELD boards by visiting http://tapr.org/kits_tass.html " ___ 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 instructions there.
[time-nuts] TimeLab and the N cornered hat...?
I’m running the latest beta, and I’ve found the spot in Edit > Trace details where you tell it the two sources that contribute to a particular dataset. I’d expect that having done that and loaded two traces A-B and B-C that I’d be able to elect to show the N cornered hat and see something different in the ADEV window, but it’s not doing anything. What am I missing? ___ 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 instructions there.
Re: [time-nuts] More HP5065 experiments
Hi, On 09/27/2015 02:35 PM, Poul-Henning Kamp wrote: In message <5607d3b0.80...@rubidium.dyndns.org>, Magnus Danielson writes: You should be able to servo the intensity using the DC intensity level detected by the photodetector. That would require a way to steer the intensity. I can try to measure that at some point. Indeed, it would require a steering-point, and you also want to tune it to be below maximum intensity so that you have a steering range. You could probably do some feed-forward from supply-voltage to first degree compensate that part. Cheers, Magnus ___ 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 instructions there.
Re: [time-nuts] More HP5065 experiments
In message <5607d3b0.80...@rubidium.dyndns.org>, Magnus Danielson writes: >You should be able to servo the intensity using the DC intensity level >detected by the photodetector. That would require a way to steer the intensity. I can try to measure that at some point. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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 instructions there.
Re: [time-nuts] More HP5065 experiments
Poul-Henning, On 09/27/2015 09:46 AM, Poul-Henning Kamp wrote: Discovery of the day: The voltage supplied to the Rb87 lamp changes the frequency on the order of 1.5e-11 per volt. I have no idea why... http://phk.freebsd.dk/hacks/HP5065A/index.html I can think of two mechanisms in play: 1) The obvious one is the light-shift as such, which comes from the intensity of the lamp. This is due to the Stark DC shift mechanism. If you dig in literature, stabilizing the intensity of pump-lamp/laser is important in reducing the effect. The same goes for the RF-field strength. 2) A little less obvious is the fact that the intensity and hence heat shift the spectrum slightly, such that the filter-cell does not do as good job in filtering the D-line. If one has replaced the filter-cell with a modern filter, this effect can still be seen. The miss-match between the filter cell and the lamp will cause leakage of the other D-line and that will counter-act the pumping and well, reduces S/N and such. An even more subtle shift is that you drift away between the pump lamp and the rubidium in the reference cell, but most of that is compensated by the fact that the lamp is so wideband sources that you hardly notice. Expect not only the feed but also temperature to shift intensity and frequency of the pump oscillator. You should be able to servo the intensity using the DC intensity level detected by the photodetector. Cheers, Magnus ___ 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 instructions there.
Re: [time-nuts] 4046 experiment for gpsdo
Hi, On 09/27/2015 02:04 AM, Bob Camp wrote: Hi If you digitize the beat note it’s fairly simple: The beat note is not really a sine wave. It’s periodic, but not a pure sine. The reason is fairly simple. The frequency changes as the beat note changes the EFC. You have a lower frequency as it gets closer to the “zero frequency”. In closed-loop yes. I actually proposed to start in open-loop mode, estimate the frequency and then close the loop after a coarse frequency adjustment have been done. In closed loop, the beat-note shape, which comes from non-linear modulation, clearly indicates the direction. You can use this knowledge to learn the polarity, as one of many methods. A semi-closed loop will get you the shape, i.e. a loop where you only close the proportional part, but not the integration part. Looking at the shape (PWM) of the beat-note you can learn the polarity and the rate the amplitude of the frequency error. Once you know the polarity and error, just initiate the integrating part accordingly and close the integration part of the loop (by setting a non-zero integrating constant). Another method is naturally to do a quadrature detection. As I said, there is so many ways to do it, and I wanted to illustrate a different approach. If you can get a 360 degree phase measure, frequency measure is almost trivial to derive from that. The net result is a signal that is a bit flat on the side that is towards the zero. It’s a bit sharper away from the zero. Fit it with a sine wave and you will get a residual. From that you can work out which side is which. You can also measure the PWM if you like. PWM < 50% => positive frequency PWM > 50% => negative frequency Cheers, Magnus Bob On Sep 26, 2015, at 5:47 PM, Hal Murray wrote: mag...@rubidium.dyndns.org said: Another method would be to measure the phase-detector beat-note frequency (most have mixer-like behavior), which you should be able to measure with quite good precision, then set the EFC accordingly and then close the loop. How do you get the sign out of a beat note? -- These are my opinions. I hate spam. ___ 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 instructions there. ___ 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 instructions there. ___ 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 instructions there.
Re: [time-nuts] 4046 experiment for gpsdo
Thanks, Yes, apologies, I didn't look at the schematic, just the text of message. Makes more sense. I'm looking at using a Neo7 GPS with the output set to something. I gather that an integer divider gives the least jitter so will probably be set 8Mhz and divide that by 8 to give 1MHz at 50% duty cycle. It will be locking a Trinble 10MHz OCXO. Divided by 5 and then 2 to also give 1MHz with 50% duty cycle. Though as Magnus points out I might have to use some hold off until the oven heats up and stabilises. Would there be any advantage in setting the Neo7 to say 1MHz or even lower and dividing both Neo and Trimble down to 1pps or some other low frequency? Cheers, Will On 27/09/15 00:36, Chuck Harris wrote: > You missed the part about the 10MHz being divided by 10 million > to produce a 1PPS signal that is compared to the second 1PPS signal... > > -Chuck Harris > > Will wrote: >> Hi, >> >> I'm new and trying to get to grips with things. >> >> If I understand correctly, please forgive if I have it wrong, This >> locks a 10MHz signal to a 1Hz (1pps) signal. What makes it lock to 10 >> 000 000Hz instead of 999 999Hz or 10 000 001Hz? Just the hope that the >> 10MHz is exactly that? >> >> Cheers, >> Will >> >> On 26/09/15 08:32, Jim Harman wrote: >>> To further demonstrate the Diode - R- C- approach, here (hopefully) >>> is a >>> screenshot of the raw DAC output vs time on my Arduino Micro (32u4) >>> based >>> system. For this test the oscillator is free running with an error >>> of about >>> 1 usec per 460 sec or 2.17x10^-9. The horizontal scale is 125 >>> sec/div (1000 >>> sec total) and the vertical is 1024 DAC counts (0-2.56 V) which >>> corresponds to 1 usec of offset between the oscillator and the >>> reference. >>> >>> You can see that there is some curvature because the capacitor is being >>> charged through a resistor and not a true current source, but as I >>> mentioned earlier this does not affect the system's ability to lock the >>> oscillator to the pps reference. When locked with a time constant of >>> 1000 >>> sec, the phase detector output is almost always less than +/- 100 >>> counts >>> from the setpoint of 500. >>> >>> The noise is due mostly to jitter in my PPS reference, which is >>> generated >>> by an Adafruit GPS module. Presumably it would be less if I had a real >>> timing receiver. >>> >>> >>> . >>> If the inserted image does not come through, I will re-send as an >>> attachment. >>> -- >>> --Jim Harman > ___ > 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 instructions there. ___ 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 instructions there.
[time-nuts] HP 5372A available in Sydney, Australia
Since its a relevant piece of kit I've included the mail from ARNSW here. Two units are available if anybody is interested. Cheers. HP 5372A and Wave Technologies DTS2070 digital time system. Amateur Radio NSW as for sale two HP 5372A time and interval analysers. Both are working with good displays. They have been tested on both inputs for the basic frequency and time measurement functions. Spare input modules are available as are some spare boards. They did not come with manuals. Also one Wave Technologies DTS2070 Digital time measurement system. Powers up OK and was in use when removed for sale. These can be viewed at the club rooms at 63 Quarry Rd Dural. Prospective buyers are welcome to test the equipment. Please contact by email at arnsw.sa...@gmail.com . The HP5372As are advertised on the ARNSW web site at http://www.arnsw.org.au/html/page_disposals.html -- -- Teach your kids Science, or somebody else will :/ ja...@ball.net vk2...@google.com callsign: vk2vjb ___ 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 instructions there.
[time-nuts] More HP5065 experiments
Discovery of the day: The voltage supplied to the Rb87 lamp changes the frequency on the order of 1.5e-11 per volt. I have no idea why... http://phk.freebsd.dk/hacks/HP5065A/index.html -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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 instructions there.
