Re: [time-nuts] Got 60HZ?
On Thu, Dec 9, 2010 at 4:19 PM, Michael Poulos wrote: > The chip number is a C8051T602.It's actually a tiny printed circuit card in > a DIP chip pinout format. Anyone know of a microcontroller that'll take > the > raw sinewave from a Ru movement? The C8051T602 is a micro controller. 8051 is a very common part. If it did a divide by ten function it was because it was loaded with software. -- = Chris Albertson Redondo Beach, California ___ 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] Got 60HZ?
WB6BNQ wrote: Michael Poulos wrote: snip Like any frequency multiply scheme you need a really accurate reference source... like a Ru movement. Not to be too nit picky (this is timenuts after all) ... the proper abbreviation for Rubidium (it is an element) is Rb. BillWB6BNQ ___ 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. Ruthenium (Ru) clocks are somewhat scarce. Bruce ___ 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] Got 60HZ?
On 10/12/2010, WB6BNQ wrote: > Michael Poulos wrote: > > snip > >> Like any frequency multiply scheme you need a really accurate >> reference source... like a Ru movement. >> > > Not to be too nit picky (this is timenuts after all) ... the proper > abbreviation > for Rubidium (it is an element) is Rb. I was wondering about that too and could only come up with RuddyUnobtainium as an extremely rare element :) Steve > BillWB6BNQ > > > > ___ > 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. > -- Steve Rooke - ZL3TUV & G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Got 60HZ?
Michael, You can get 32768 Hz from 10 MHz using a single 8 pin PIC. http://www.ni6e.com/time/10M32K.html Regards, Peter On 12/9/2010 4:19 PM, Michael Poulos wrote: The chip was one I got on eBay from a different seller than the Ru movement. The chip number is a C8051T602.It's actually a tiny printed circuit card in a DIP chip pinout format. I have no idea how many or few of these bad boys are to be found anywhere. Anyone know of a microcontroller that'll take the raw sinewave from a Ru movement? THAT would be nice! BTW, a really cool frequency to make would be the 32768HZ of a normal quartz movement. Take a radio controlled wall clock and rubidiumize it and let it self-reset. in between self-resettings it'll remain astoundingly accurate, great for lousy reception areas. ___ 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] Got 60HZ?
Michael Poulos wrote: snip > Like any frequency multiply scheme you need a really accurate > reference source... like a Ru movement. > Not to be too nit picky (this is timenuts after all) ... the proper abbreviation for Rubidium (it is an element) is Rb. BillWB6BNQ ___ 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] Got 60HZ?
Chris Albertson wrote: What you are doing is "dithering". That is the "Leap Count". There is a better way that gives you the exact solution. If you think about it, what is the computer doing between counts? nothing really. Put that time to use. Why not measure the the 1Khz period. Or measure the period of the last 1000 counts. then toggle the output at 60/1000 of that period. This is a "software phase lock loop" . Another way to think about this is to think what would you do if your frqency reference was a one pulse per second "tick". I got the "dithering" idea from an obvious source: the calendar. Not knowing about dithering but knowing everyone on the list knows about leap time intervals, the term I used is a no-brainer. With a 1HZ output, the thing I would do is feed it into an Arduino for the display. If I wanted a display with .1 of a sec display added, I'd have let's say the ramp-up to HIGH trigger the Arduino and code in time-waste code as needed to get the flipping intervals - including any leap wasted CPU cycles. Like any frequency multiply scheme you need a really accurate reference source... like a Ru movement. ___ 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] Got 60HZ?
paul swed wrote: WHAT chip are you using that has the nice divide by 10 outputs please? I have been wiring 74ls XXXs for years what a pain. Tired of the soldering. Thanks Paul The chip was one I got on eBay from a different seller than the Ru movement. The chip number is a C8051T602.It's actually a tiny printed circuit card in a DIP chip pinout format. I have no idea how many or few of these bad boys are to be found anywhere. Anyone know of a microcontroller that'll take the raw sinewave from a Ru movement? THAT would be nice! BTW, a really cool frequency to make would be the 32768HZ of a normal quartz movement. Take a radio controlled wall clock and rubidiumize it and let it self-reset. in between self-resettings it'll remain astoundingly accurate, great for lousy reception areas. ___ 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] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140
Hi Robert, Yes, its for the 10kHz output. Basically the units will be part of a set of timing computers that will be used at fixed locations to measure time intervals. That's very fast, how did you test it at that speed? Thanks - Dabney On 12/9/2010 3:02 PM, Robert Atkinson wrote: Hi Dabney, Why the Jupiter? I assume it's for the 10kHz output, but can't see where that applies to automotive timing. I have a couple of Jupiters and also have an interest in automotive speed events. The fastest speedometer I've designed and built so far did over 770MPH. Regards, Robert G8RPI. --- On Thu, 9/12/10, Dabney Crump wrote: From: Dabney Crump Subject: [time-nuts] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140 To: time-nuts@febo.com Date: Thursday, 9 December, 2010, 21:43 Hi All, I'm looking for approximately 10 of the Jupiter GPS modules for a personal timing project; I time automotive speed events. I'm aware of the units available on eBay from Hong Kong but would like to try to source them from US markets first. Thanks for any assistance, Dabney in Denver 303-324-1084 ___ 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] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140
Would be interested Regards Paul. On Thu, Dec 9, 2010 at 6:25 PM, Oz-in-DFW wrote: > i don't have 10, but I have a few that will want new homes. will have to > dig this WE > > On 12/9/2010 3:43 PM, Dabney Crump wrote: > > Hi All, > > I'm looking for approximately 10 of the Jupiter GPS modules > > for a personal timing project; I time automotive speed events. > > > > I'm aware of the units available on eBay from Hong Kong but > > would like to try to source them from US markets first. > > > > Thanks for any assistance, > > Dabney in Denver > > 303-324-1084 > > > > > > > > > > ___ > > 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. > > -- > mailto:o...@ozindfw.net > Oz > POB 93167 > Southlake, TX 76092 (Near DFW Airport) > > > > > ___ > 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] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140
i don't have 10, but I have a few that will want new homes. will have to dig this WE On 12/9/2010 3:43 PM, Dabney Crump wrote: > Hi All, > I'm looking for approximately 10 of the Jupiter GPS modules > for a personal timing project; I time automotive speed events. > > I'm aware of the units available on eBay from Hong Kong but > would like to try to source them from US markets first. > > Thanks for any assistance, > Dabney in Denver > 303-324-1084 > > > > > ___ > 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. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Got 60HZ?
My general solution to generating clock frequencies of any frequency is to take a middle frequency from the divider chain (say 10kHz) and feed it into a PLL chip with a divider (say 3 or 6 using a Johnson counter which resets) in the feedback loop. This multiplies the VCO output by 3 (30kHz or 60kHz) which will then divide down to 60Hz with very little phase noise. The only difficulty is the need for a reset that is synchronised with the PPS signal. (use a D latch or two) cheers, Neville Michie Recently I bought a Efratom Ru frequency standard from eBay and a frequency divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a 1HZ output. Today I thought of a way to make a nice 60HZ so you can use a mains-powered clock for the display (using amplifier and transformer wired "backwards"). ___ 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] Timing over low bandwidth channels
On 12/09/2010 03:16 PM, jimlux wrote: Hal Murray wrote: If you can indeed track a 1W signal from ~ Colorado, there might indeed be some timing use for the system. I have a start at understanding how much data you can get through a channel. There is a tradeoff between data rate and error rate and it depends on the signal/noise ratio. That's the Shannon bound.. (or Shannon-Hartley).. C = B*log2(1+S/N) You can get pretty darn close (hundredths of a dB) to this limit with coding. Is there a similar sort of high level picture about sending timing info? I'm not even sure what the units are. That's a bit trickier to conceptualize... In the data bit case, you can work at the "one bit" scale.. and say something about the probability that the bit is wrong. ANd, you can combine multiple bits and drive the probability of an error over all those bits combined down. But for "time" or "frequency" it's a bit trickier. You have to specify the time scale over which you're interested (I suppose that relates to the bandwidth in the Shannon formula). But more to the point, in digital communications there's a clear "two-state" thing..either the bit is correct or it's not. Time/Frequency has "degrees of wrongness" Which is the reason you look a bit wider on Shannon's work and not use the oversimplified model of above. Shannon's article(s) cover both analog and digital transmissions. The bandwidth you use for your signal will be the bandwidth you toss into the formula, where spread spectrum helps to confuse the issue. The time and frequency reception is not all that strange. The analysis is done fairly deeply for GPS, where a 40 W transmission provides timing for 1/3 of the earth surface area some 26000 km away or so. 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] 3586A HQ PDF Manual available
On 12/9/2010 11:18 PM, Roberto Barrios wrote: Luckily I've been able to invest a few unexpected evenings on the manual and all the long boring work is already done. I'm now reviewing it thoroughly as I'd like to avoid having to fix silly mistakes after people have already downloaded it (something which is plainly unavoidable, I'm just trying to minimize the embarrasment...) It is a matter of hours, you'll get it for the weekend :-) Thanks for the interest ! Roberto EB4EQA I have been able to reduce considerably the size of that PDF by using the optimizing function of Adobe Acrobat, without loss of quality. The optimized copy is here : [1]http://dl.dropbox.com/u/15089947/3586%20-%20Operating%20Manual%20%28 HQ_opt%29.pdf Now it is 61,227 kB instead of the original 116,380 kB If you will publish an amended copy, I will process that as well. 73 Alberto I2PHD References 1. http://dl.dropbox.com/u/15089947/3586%20-%20Operating%20Manual%20%28HQ_opt%29.pdf ___ 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] Time Code generator
On 12/09/2010 02:46 PM, jimlux wrote: Magnus Danielson wrote: On 12/08/2010 07:18 PM, jimlux wrote: Chris Albertson wrote: Adding time code to video would be redundant. All video is already time coded. All *digital* video is timecoded.. No, not all digital video. The time-code is optional in many of the transfer formats. You're right.. I was thinking more that analog certainly isn't always timecoded, but at least for digital, there's an inherent frame counter, There is as inherent frame counting in the analog PAL and NTSC signals as there is for their digital counter-part in SDI. and dropped/doubled/partial frames are unusual in digital video systems. Not after the frame-store farm... They're positively frequent in analog systems (esp consumer vhs!) But you'd still get caught if the frame rate isn't the same across your system (which is often the case) Inside a production location yes, as the house clock dictates the time for all equipment... but not between the production locations, the solution being the use of a frame-store farm to "clean" the incoming signal into the local house-clock phase and frequency. A number of false starts to align things to GPS have been attempted, but there has been some speed in the development. One progress was the definition of the SMPTE EPOCH in SMPTE 404M (which bounced the trial publication after feedback from a time-nut asking what time-zone the midnight of 1 Jan 1958 was being referenced, naturally it was UTC midnight which was intended and thus the Zulu time-zone). The idea with the SMPTE EPOCH (defined to where TAI and UTC align up) is that all sample-rates, line-rate, frame-rates etc. for all signals has T=0 at that time and then just follow the development of TAI, while the time of day would follow UTC. Consumer gear also usually doesn't have any ability to gen-lock. Unfortunately. Some of it is hackable thought. It's been 12 years since I sat in an edit bay, so I'll bet that analog gear is pretty much out of the picture by now, though. Analog black-bursts is still here. I think that's the video equivalent of the 10MHz reference distribution. It is. 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] 3586A HQ PDF Manual available
Hi Pete, Sal, Luckily I've been able to invest a few unexpected evenings on the manual and all the long boring work is already done. I'm now reviewing it thoroughly as I'd like to avoid having to fix silly mistakes after people have already downloaded it (something which is plainly unavoidable, I'm just trying to minimize the embarrasment...) It is a matter of hours, you'll get it for the weekend :-) Thanks for the interest ! Roberto EB4EQA -- Message: 3 Date: Thu, 9 Dec 2010 10:16:10 -0800 From: Pete Lancashire Subject: Re: [time-nuts] 3586A HQ PDF Manual available To: Discussion of precise time and frequency measurement Message-ID: Content-Type: text/plain; charset=UTF-8 2nd that ! -pete On Tue, Nov 30, 2010 at 2:28 PM, paul swed wrote: Just want to say a very nice job that you have done Roberto. Regards Paul WB8TSL On Tue, Nov 30, 2010 at 9:26 AM, SAL CORNACCHIA wrote: Hi Roberto, I would be interested? Thank You ?Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Roberto Barrios To: time-nuts@febo.com Sent: Mon, November 29, 2010 5:18:07 PM Subject: [time-nuts] 3586A HQ PDF Manual available Hi all, I've been lucky enough to get a 3586A in good shape, with no manuals. I found the operating manual at Agilent's site (poor quality) and the (good quality) scans at KO4BB, made by someone unknown to me. I went thru the trouble of correcting rotation, borders and levels of each of those pages one by one and I've built a (big) PDF file with them. Still not searchable but I've bookmarked every entry of the Table of Contents so you can go to the section you need effortlessly. You can get your copy at http://www.rbarrios.com/manuals After a few evenings working on it, I'm now considering (not) doing the same with the two volumes of the service manual. Is there any interest? Regards, Roberto EB4EQA ___ 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] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140
Hi Dabney, Why the Jupiter? I assume it's for the 10kHz output, but can't see where that applies to automotive timing. I have a couple of Jupiters and also have an interest in automotive speed events. The fastest speedometer I've designed and built so far did over 770MPH. Regards, Robert G8RPI. --- On Thu, 9/12/10, Dabney Crump wrote: From: Dabney Crump Subject: [time-nuts] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140 To: time-nuts@febo.com Date: Thursday, 9 December, 2010, 21:43 Hi All, I'm looking for approximately 10 of the Jupiter GPS modules for a personal timing project; I time automotive speed events. I'm aware of the units available on eBay from Hong Kong but would like to try to source them from US markets first. Thanks for any assistance, Dabney in Denver 303-324-1084 ___ 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] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140
Will be interesting to see if there is a US source and still at a reasonable cost. I did not find one On Thu, Dec 9, 2010 at 4:43 PM, Dabney Crump wrote: > Hi All, > I'm looking for approximately 10 of the Jupiter GPS modules > for a personal timing project; I time automotive speed events. > > I'm aware of the units available on eBay from Hong Kong but > would like to try to source them from US markets first. > > Thanks for any assistance, > Dabney in Denver > 303-324-1084 > > > > > ___ > 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] WTB up to 10 pieces - Rockwell Jupiter - TU30-D140
Hi All, I'm looking for approximately 10 of the Jupiter GPS modules for a personal timing project; I time automotive speed events. I'm aware of the units available on eBay from Hong Kong but would like to try to source them from US markets first. Thanks for any assistance, Dabney in Denver 303-324-1084 ___ 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] reference oscillator input circuit
Hi ...and sometimes they leave the Schottkys out. The original request was not a really low jitter application. I think Jim can get away with an active circuit. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John Miles Sent: Thursday, December 09, 2010 4:00 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] reference oscillator input circuit > No, actually to feed a bunch of synthesizer chains (for which the sine > wave will work fine) and to drive sampling clocks on ADC/DAC (for which > one wants a low jitter square wave). > > A digital radio... There are some nice residual plots for AC and CMOS chips at http://www.xs4all.nl/~martein/pa3ake/hmode/dds_ad9910_pmnoise.html . Seems like the AD9515 family in PECL mode is about as good as anything is likely to get at VHF. However, why not use the sine wave directly, converted to differential with a transformer and clipped by back-to-back Schottkys? At VHF clock frequencies any active sine-to-square conversion circuit I'm aware of will contribute more jitter than the ADC's own tJ spec. (Put another way, if I'm a semiconductor house designing a high-end ADC or DAC, I am probably going to put all the secret sauce I have into the on-chip clock conditioning, leaving little or no room for improvement outside the chip.) The eval boards from the various ADC manufacturers bear this out. No one puts anything but a 50-ohm SMA jack, transformer and Schottkys on their clock inputs. -- john, KE5FX ___ 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] reference oscillator input circuit
> No, actually to feed a bunch of synthesizer chains (for which the sine > wave will work fine) and to drive sampling clocks on ADC/DAC (for which > one wants a low jitter square wave). > > A digital radio... There are some nice residual plots for AC and CMOS chips at http://www.xs4all.nl/~martein/pa3ake/hmode/dds_ad9910_pmnoise.html . Seems like the AD9515 family in PECL mode is about as good as anything is likely to get at VHF. However, why not use the sine wave directly, converted to differential with a transformer and clipped by back-to-back Schottkys? At VHF clock frequencies any active sine-to-square conversion circuit I'm aware of will contribute more jitter than the ADC's own tJ spec. (Put another way, if I'm a semiconductor house designing a high-end ADC or DAC, I am probably going to put all the secret sauce I have into the on-chip clock conditioning, leaving little or no room for improvement outside the chip.) The eval boards from the various ADC manufacturers bear this out. No one puts anything but a 50-ohm SMA jack, transformer and Schottkys on their clock inputs. -- john, KE5FX ___ 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] reference oscillator input circuit
jimlux wrote: Javier Herrero wrote: El 09/12/2010 15:21, jimlux escribió: Javier Herrero wrote: Good to know. Now I see what not to use :) I was supposing that the hysteresis would not be so high being low voltage signalling, and since they are used for low-jitter applications. But really I've only used them for their intended main applications :) hysteresis is in the 100mV minimum range, and max peak amplitude is in the 0.9 to 1 Volt range (they'll have a bias point a bit over a volt, and a lot of them do not do well at all if you swing close to the supply rail) Maybe with external clamps and over drive it. Yes, I was thinking in that way. But surely they are better solutions :) hence my question to the list.. I'm going to gather all the responses and summarize them for the list later today. ___ 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. Since noise modulation (power supply and device noise) of device parameters (eg collector base capacitance) can be a significant source of phase noise adding some emitter degeneration in a long tailed pair and shunting the collector load resistors with inductors (eg a transformer winding) should be an effective way of reducing such phase noise. A capacitor shunting the collector load can also be effective in reducing the circuit bandwidth closer to the optimum and desensitising the circuit bandwidth to device parameter variations. However avoiding high Q parasitic resonances with the output inductors (or transformer) will be necessary. Bruce ___ 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] Got 60HZ?
If one actually requires a low phase noise/low jitter output using a Schmitt trigger is not a good idea. The effective threshold is modulated by the internal noise of the schmitt trigger circuit itself. This effect can be very significant with low phase noise sources and a fast Schmitt trigger. For noisy input signals the signal phase noise will modulate the phase of the output signal. Bruce Chris Albertson wrote: What you are doing is "dithering". That is the "Leap Count". There is a better way that gives you the exact solution. If you think about it, what is the computer doing between counts? nothing really. Put that time to use. Why not measure the the 1Khz period. Or measure the period of the last 1000 counts. then toggle the output at 60/1000 of that period. This is a "software phase lock loop" . Another way to think about this is to think what would you do if your frqency reference was a one pulse per second "tick". About how to "square" a wave.Some people suggest amplifying the sine wave then feeding it to a 74xxx series logic gate. There is no need to amplify. What you do is compare the sine wave to zero. All sine waves of any amplitude even if it is .1 Volt or 100 Volt peak to peak, they all cross zero so you flip the square wave each the sine wave crosses zero. But do it with a "Schidt trigger". This is a very noise immune circuit. Place the gard bands at -0.1V and +0.1V and it will work with any sine wave, no amplifier required. Also you can build it with an 8 pin dip chip, no need for a 14 pin chip. See here for more on this. http://en.wikipedia.org/wiki/Schmitt_trigger On Wed, Dec 8, 2010 at 8:13 PM, Michael Poulos wrote: Recently I bought a Efratom Ru frequency standard from eBay and a frequency divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a 1HZ output. Today I thought of a way to make a nice 60HZ so you can use a mains-powered clock for the display (using amplifier and transformer wired "backwards"). ___ 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] 3586A HQ PDF Manual available
2nd that ! -pete On Tue, Nov 30, 2010 at 2:28 PM, paul swed wrote: > Just want to say a very nice job that you have done Roberto. > Regards > Paul > WB8TSL > > On Tue, Nov 30, 2010 at 9:26 AM, SAL CORNACCHIA wrote: > >> Hi Roberto, >> >> I would be interested? >> >> Thank You >> Best regards, >> Sal C. Cornacchia >> Electronic RF Microwave Engineer (Ret.) >> >> >> >> >> >> >> >> >> From: Roberto Barrios >> To: time-nuts@febo.com >> Sent: Mon, November 29, 2010 5:18:07 PM >> Subject: [time-nuts] 3586A HQ PDF Manual available >> >> Hi all, >> >> I've been lucky enough to get a 3586A in good shape, with no manuals. I >> found >> the operating manual at Agilent's site (poor quality) and the (good >> quality) >> scans at KO4BB, made by someone unknown to me. I went thru the trouble of >> correcting rotation, borders and levels of each of those pages one by one >> and >> I've built a (big) PDF file with them. Still not searchable but I've >> bookmarked >> every entry of the Table of Contents so you can go to the section you need >> effortlessly. >> >> You can get your copy at http://www.rbarrios.com/manuals >> >> After a few evenings working on it, I'm now considering (not) doing the >> same >> with the two volumes of the service manual. Is there any interest? >> >> Regards, >> Roberto EB4EQA >> >> ___ >> 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. > ___ 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] GPS antenna info needed
I have one of the TAPR antennas: http://tapr.org/gps_ant1a.html I'm willing to part with for the price of shipping. -Eric On Thu, Dec 9, 2010 at 9:57 AM, Tom Holmes wrote: > Perry... > > From time to time (OK, that was a little too lame) TAPR has GPS antennas for > good prices. > > www.tapr.org. > > > > Tom Holmes, N8ZM > Tipp City, OH > EM79 > > >> -Original Message- >> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >> Behalf Of Perry Sandeen >> Sent: Wednesday, December 08, 2010 11:17 PM >> To: time-nuts-requ...@febo.com >> Subject: [time-nuts] GPS antenna info needed >> >> My magnetic base hockey puck amplified GPS antenna for my Lucent receiver >> died. I had purchased it at the Dayton Hamvention so I don’t remember the >> dealer. >> >> I’ve found quite a few sellers on Amazon that are in the USA and their >> prices are >> all about the same. >> >> Does anyone have a recommendation? >> >> I’d rather spend a few dollars more for a quality unit but I don’t know if >> they are all >> from the same supplier in china and they only difference is the dealers >> price. >> >> TIA >> Perrier >> >> >> >> >> >> ___ >> 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. -- --Eric _ Eric Garner ___ 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] GPS antenna info needed
Perry... From time to time (OK, that was a little too lame) TAPR has GPS antennas for good prices. www.tapr.org. Tom Holmes, N8ZM Tipp City, OH EM79 > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Perry Sandeen > Sent: Wednesday, December 08, 2010 11:17 PM > To: time-nuts-requ...@febo.com > Subject: [time-nuts] GPS antenna info needed > > My magnetic base hockey puck amplified GPS antenna for my Lucent receiver > died. I had purchased it at the Dayton Hamvention so I don’t remember the > dealer. > > I’ve found quite a few sellers on Amazon that are in the USA and their prices > are > all about the same. > > Does anyone have a recommendation? > > I’d rather spend a few dollars more for a quality unit but I don’t know if > they are all > from the same supplier in china and they only difference is the dealers price. > > TIA > Perrier > > > > > > ___ > 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] Got 60HZ?
What you are doing is "dithering". That is the "Leap Count". There is a better way that gives you the exact solution. If you think about it, what is the computer doing between counts? nothing really. Put that time to use. Why not measure the the 1Khz period. Or measure the period of the last 1000 counts. then toggle the output at 60/1000 of that period. This is a "software phase lock loop" . Another way to think about this is to think what would you do if your frqency reference was a one pulse per second "tick". About how to "square" a wave.Some people suggest amplifying the sine wave then feeding it to a 74xxx series logic gate. There is no need to amplify. What you do is compare the sine wave to zero. All sine waves of any amplitude even if it is .1 Volt or 100 Volt peak to peak, they all cross zero so you flip the square wave each the sine wave crosses zero. But do it with a "Schidt trigger". This is a very noise immune circuit. Place the gard bands at -0.1V and +0.1V and it will work with any sine wave, no amplifier required. Also you can build it with an 8 pin dip chip, no need for a 14 pin chip. See here for more on this. http://en.wikipedia.org/wiki/Schmitt_trigger On Wed, Dec 8, 2010 at 8:13 PM, Michael Poulos wrote: > Recently I bought a Efratom Ru frequency standard from eBay and a frequency > divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a 1HZ output. > Today I thought of a way to make a nice 60HZ so you can use a mains-powered > clock for the display (using amplifier and transformer wired "backwards"). -- = Chris Albertson Redondo Beach, California ___ 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] 3586A HQ PDF Manual available
Hi Roberto, Do You have any idea when the two volume Service Manual for the HP 3586A,B,C will be uploaded to Your web site. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) The information contained in this e-mail transmission is privileged and/or confidential intended solely for the exclusive use of the individual addressee. If you are not the intended addressee you are hereby notified that any retention, disclosure or other use is strictly prohibited. If you have received this notification in error, please immediately contact the sender and delete the material. From: Roberto Barrios To: time-nuts@febo.com Sent: Mon, November 29, 2010 5:18:07 PM Subject: [time-nuts] 3586A HQ PDF Manual available Hi all, I've been lucky enough to get a 3586A in good shape, with no manuals. I found the operating manual at Agilent's site (poor quality) and the (good quality) scans at KO4BB, made by someone unknown to me. I went thru the trouble of correcting rotation, borders and levels of each of those pages one by one and I've built a (big) PDF file with them. Still not searchable but I've bookmarked every entry of the Table of Contents so you can go to the section you need effortlessly. You can get your copy at http://www.rbarrios.com/manuals After a few evenings working on it, I'm now considering (not) doing the same with the two volumes of the service manual. Is there any interest? Regards, Roberto EB4EQA ___ 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] Got 60HZ?
Familiar with that. I thought he had another chip from his first email. Maybe I am wrong it always seemed like a reasonable chip someone would make. On Thu, Dec 9, 2010 at 11:47 AM, Cook Mike wrote: > Le 09/12/2010 16:54, paul swed a écrit : > > How about a PIC again, as per the example at > http://www.leapsecond.com/tools/PPSDIV.ASM > >> WHAT chip are you using that has the nice divide by 10 outputs please? >> I have been wiring 74ls XXXs for years what a pain. Tired of the >> soldering. >> Thanks >> Paul >> >> On Thu, Dec 9, 2010 at 7:47 AM, Bob Camp wrote: >> >> < snipped> >> >> >>> ___ >>> 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. > ___ 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] Got 60HZ?
Le 09/12/2010 16:54, paul swed a écrit : How about a PIC again, as per the example at http://www.leapsecond.com/tools/PPSDIV.ASM WHAT chip are you using that has the nice divide by 10 outputs please? I have been wiring 74ls XXXs for years what a pain. Tired of the soldering. Thanks Paul On Thu, Dec 9, 2010 at 7:47 AM, Bob Camp wrote: < snipped> ___ 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] Got 60HZ?
WHAT chip are you using that has the nice divide by 10 outputs please? I have been wiring 74ls XXXs for years what a pain. Tired of the soldering. Thanks Paul On Thu, Dec 9, 2010 at 7:47 AM, Bob Camp wrote: > Hi > > Another simple approach: > > Run a PIC off of it's internal R/C clock > Divide to both 60 Hz with a divider that will do M, M-N, M+N where N is > 1,2,3,4,5 and covers the expected tolerance of the clock > Divide the 60 Hz to 1 Hz > Compare the 1 Hz to a pps output > Based on the 1 Hz being early / late, update N for the next second. > > It actually takes less time to code it than to explain it like this. > > If the built in clock is good to ~ 0.1 % on a second to second basis, your > clock will be far more accurate than the eye can detect. > > Lots of ways to do it. > > Bob > > > On Dec 9, 2010, at 3:47 AM, francesco messineo wrote: > > > Hello, > > > > On Thu, Dec 9, 2010 at 5:13 AM, Michael Poulos > wrote: > >> Recently I bought a Efratom Ru frequency standard from eBay and a > frequency > >> divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a 1HZ output. > >> Today I thought of a way to make a nice 60HZ so you can use a > mains-powered > >> clock for the display (using amplifier and transformer wired > "backwards"). > >> But, now you'll need 60HZ. A European has it easy with 50HZ as you use a > >> BASIC Stamp or Arduino to divide the 100HZ output. But for 60HZ I came > up > >> with a solution: > >> > >> You set up the Arduino to take the 10KHZ from the divider chip and > program > >> it to count off 83 pulses to flip an output. But wait! Unless you add a > >> "leap count" every 3 flips of the output, it'll run fast. Assume at the > >> start the Arduino output starts high then turns low: > >> > >> (83+83+84+83+83+84)*20 = 10,000 pulses = one second > >> H__L__H__L__H__L > >> > >> Every output cycle and a half the voltage swing is a little over 1 > percent > >> longer because of the leap count. This means that the distortion adds a > >> slight inaccuracy, not enough to upset New Year's revelers. But if you > want > >> a better 60HZ, try using the 100KHZ: > >> > >> (833+833+834+833+833+834)*20 = one second > >> > >> You see where this is going with leap counts. The ultimate of course is > one > >> really good Arduino and (after a hex inverter to amplify it) take the > >> straight 10MHZ and apply this leap count technique: > >> > >> (8+8+83334+8+8+83334)*20 = one really accurately made > 60HZ = > >> one nice second, just the thing for a Nixie clock. :) > >> > >> Now, what is a good hex inverter to take the 10 million HZ of my > rubidiom > >> movement to feed a frequency divider chip (and later Arduino)? It needs > to > >> take the .5 of a volt sinewaIe and squarewave it and in a normal 14 pin > DIP > >> (breadboardable) package. > > > > > > if you are not afraid of a little microcontroller programming, why not > > use a software DDS approach like this: > > > > > > http://www.myplace.nu/avr/minidds/index.htm > > > > it can output a nice sine wave at 60 Hz (or whatever) from say a 10 > > MHz clock really easily and the frequency is also easily tunable in > > software. > > > > I built several similar low frequency (audio range) software DDS using > > AVR and other microcontrollers. > > I usually add a one or two stage active low pass filter after the R/2R > > network. I also used to build the R/2R network out of selected 1% 10K > > resistors, final resistor match is usually good to 0.1% tolerance, but > > in some boards I just put 5% parts. > > Software is basicly an adder and you use the highest byte as a pointer > > to the ram or rom waveform samples, once you understand how it works, > > it's really easy to adapt to your needs. Usually the waveform you > > obtain has a DC offset, but that's easily solved too. > > > > Hope it helps. > > > > Frank IZ8DWF > > > > ___ > > 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] reference oscillator input circuit
Javier Herrero wrote: El 09/12/2010 15:21, jimlux escribió: Javier Herrero wrote: Good to know. Now I see what not to use :) I was supposing that the hysteresis would not be so high being low voltage signalling, and since they are used for low-jitter applications. But really I've only used them for their intended main applications :) hysteresis is in the 100mV minimum range, and max peak amplitude is in the 0.9 to 1 Volt range (they'll have a bias point a bit over a volt, and a lot of them do not do well at all if you swing close to the supply rail) Maybe with external clamps and over drive it. Yes, I was thinking in that way. But surely they are better solutions :) hence my question to the list.. I'm going to gather all the responses and summarize them for the list later today. ___ 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] reference oscillator input circuit
El 09/12/2010 15:21, jimlux escribió: Javier Herrero wrote: Good to know. Now I see what not to use :) I was supposing that the hysteresis would not be so high being low voltage signalling, and since they are used for low-jitter applications. But really I've only used them for their intended main applications :) hysteresis is in the 100mV minimum range, and max peak amplitude is in the 0.9 to 1 Volt range (they'll have a bias point a bit over a volt, and a lot of them do not do well at all if you swing close to the supply rail) Maybe with external clamps and over drive it. Yes, I was thinking in that way. But surely they are better solutions :) Regards, Javier -- Javier HerreroEMAIL: jherr...@hvsistemas.com Chief Technology Officer HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ 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] reference oscillator input circuit
Javier Herrero wrote: Good to know. Now I see what not to use :) I was supposing that the hysteresis would not be so high being low voltage signalling, and since they are used for low-jitter applications. But really I've only used them for their intended main applications :) hysteresis is in the 100mV minimum range, and max peak amplitude is in the 0.9 to 1 Volt range (they'll have a bias point a bit over a volt, and a lot of them do not do well at all if you swing close to the supply rail) Maybe with external clamps and over drive it. ___ 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] reference oscillator input circuit
Good to know. Now I see what not to use :) I was supposing that the hysteresis would not be so high being low voltage signalling, and since they are used for low-jitter applications. But really I've only used them for their intended main applications :) Best regards, Javier El 09/12/2010 14:50, jimlux escribió: Javier Herrero wrote: I was thinking about how good or how bad would result the use of an LVDS line receiver ... but it is only a though :) That's what I was using before, and it doesn't work very well.. Small common mode voltage range and large hysteresis. They're really designed to take square wave(ish) inputs. ___ 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. -- Javier HerreroEMAIL: jherr...@hvsistemas.com Chief Technology Officer HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ 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] Timing over low bandwidth channels
Hal Murray wrote: If you can indeed track a 1W signal from ~ Colorado, there might indeed be some timing use for the system. I have a start at understanding how much data you can get through a channel. There is a tradeoff between data rate and error rate and it depends on the signal/noise ratio. That's the Shannon bound.. (or Shannon-Hartley).. C = B*log2(1+S/N) You can get pretty darn close (hundredths of a dB) to this limit with coding. Is there a similar sort of high level picture about sending timing info? I'm not even sure what the units are. That's a bit trickier to conceptualize... In the data bit case, you can work at the "one bit" scale.. and say something about the probability that the bit is wrong. ANd, you can combine multiple bits and drive the probability of an error over all those bits combined down. But for "time" or "frequency" it's a bit trickier. You have to specify the time scale over which you're interested (I suppose that relates to the bandwidth in the Shannon formula). But more to the point, in digital communications there's a clear "two-state" thing..either the bit is correct or it's not. Time/Frequency has "degrees of wrongness" ___ 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] reference oscillator input circuit
Chris Albertson wrote: Of all the ways to "square" a sine wave I think the best might be to use a PLL. the raising edge of your output square wave would trigger a sample of the input sine wave. The distance from zero volts of that sample is the phase error. The goal is to have the raising edge of the square wave happen just as the sine crosses zero. But if it's not dead-on you get an error signal that can be either positive or negative and this error is low pass filtered and then applied as a correction. But my guess is that if you are using this to feed a 'scope a reference frequency the scope will have it's own PLL. No, actually to feed a bunch of synthesizer chains (for which the sine wave will work fine) and to drive sampling clocks on ADC/DAC (for which one wants a low jitter square wave). A digital radio... ___ 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] reference oscillator input circuit
Javier Herrero wrote: I was thinking about how good or how bad would result the use of an LVDS line receiver ... but it is only a though :) That's what I was using before, and it doesn't work very well.. Small common mode voltage range and large hysteresis. They're really designed to take square wave(ish) inputs. ___ 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] Time Code generator
Magnus Danielson wrote: On 12/08/2010 07:18 PM, jimlux wrote: Chris Albertson wrote: Adding time code to video would be redundant. All video is already time coded. All *digital* video is timecoded.. No, not all digital video. The time-code is optional in many of the transfer formats. You're right.. I was thinking more that analog certainly isn't always timecoded, but at least for digital, there's an inherent frame counter, and dropped/doubled/partial frames are unusual in digital video systems. They're positively frequent in analog systems (esp consumer vhs!) But you'd still get caught if the frame rate isn't the same across your system (which is often the case) Consumer gear also usually doesn't have any ability to gen-lock. It's been 12 years since I sat in an edit bay, so I'll bet that analog gear is pretty much out of the picture by now, though. Analog black-bursts is still here. I think that's the video equivalent of the 10MHz reference distribution. ___ 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] Got 60HZ?
Hi Another simple approach: Run a PIC off of it's internal R/C clock Divide to both 60 Hz with a divider that will do M, M-N, M+N where N is 1,2,3,4,5 and covers the expected tolerance of the clock Divide the 60 Hz to 1 Hz Compare the 1 Hz to a pps output Based on the 1 Hz being early / late, update N for the next second. It actually takes less time to code it than to explain it like this. If the built in clock is good to ~ 0.1 % on a second to second basis, your clock will be far more accurate than the eye can detect. Lots of ways to do it. Bob On Dec 9, 2010, at 3:47 AM, francesco messineo wrote: > Hello, > > On Thu, Dec 9, 2010 at 5:13 AM, Michael Poulos wrote: >> Recently I bought a Efratom Ru frequency standard from eBay and a frequency >> divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a 1HZ output. >> Today I thought of a way to make a nice 60HZ so you can use a mains-powered >> clock for the display (using amplifier and transformer wired "backwards"). >> But, now you'll need 60HZ. A European has it easy with 50HZ as you use a >> BASIC Stamp or Arduino to divide the 100HZ output. But for 60HZ I came up >> with a solution: >> >> You set up the Arduino to take the 10KHZ from the divider chip and program >> it to count off 83 pulses to flip an output. But wait! Unless you add a >> "leap count" every 3 flips of the output, it'll run fast. Assume at the >> start the Arduino output starts high then turns low: >> >> (83+83+84+83+83+84)*20 = 10,000 pulses = one second >> H__L__H__L__H__L >> >> Every output cycle and a half the voltage swing is a little over 1 percent >> longer because of the leap count. This means that the distortion adds a >> slight inaccuracy, not enough to upset New Year's revelers. But if you want >> a better 60HZ, try using the 100KHZ: >> >> (833+833+834+833+833+834)*20 = one second >> >> You see where this is going with leap counts. The ultimate of course is one >> really good Arduino and (after a hex inverter to amplify it) take the >> straight 10MHZ and apply this leap count technique: >> >> (8+8+83334+8+8+83334)*20 = one really accurately made 60HZ = >> one nice second, just the thing for a Nixie clock. :) >> >> Now, what is a good hex inverter to take the 10 million HZ of my rubidiom >> movement to feed a frequency divider chip (and later Arduino)? It needs to >> take the .5 of a volt sinewaIe and squarewave it and in a normal 14 pin DIP >> (breadboardable) package. > > > if you are not afraid of a little microcontroller programming, why not > use a software DDS approach like this: > > > http://www.myplace.nu/avr/minidds/index.htm > > it can output a nice sine wave at 60 Hz (or whatever) from say a 10 > MHz clock really easily and the frequency is also easily tunable in > software. > > I built several similar low frequency (audio range) software DDS using > AVR and other microcontrollers. > I usually add a one or two stage active low pass filter after the R/2R > network. I also used to build the R/2R network out of selected 1% 10K > resistors, final resistor match is usually good to 0.1% tolerance, but > in some boards I just put 5% parts. > Software is basicly an adder and you use the highest byte as a pointer > to the ram or rom waveform samples, once you understand how it works, > it's really easy to adapt to your needs. Usually the waveform you > obtain has a DC offset, but that's easily solved too. > > Hope it helps. > > Frank IZ8DWF > > ___ > 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] Timing over low bandwidth channels
Hi ... and for a very low power system, there's no reason to stick with a "short" 512 bit data set, or a "fast" 1 second rep rate. If the signal is a "only at night" sort of thing (as I'm guessing it is over that path), all you really might do is a couple of time transfers a night. A code that marked 10 minute slots would do the trick. Make it nice and long so you don't loose precision. Bob On Dec 9, 2010, at 5:55 AM, Poul-Henning Kamp wrote: > In message <20101209105031.6104c800...@ip-64-139-1-69.sjc.megapath.net>, Hal > Murray writes: > >> Is there a similar sort of high level picture about sending timing info? >> I'm >> not even sure what the units are. > > Basically with timing you only send one bit: "now" > > The most precise way to send that bit is to use a very long PRNG > spreading code, and identify the correlator output peak using > statistical estimation on the slopes up to the peak. > > DCF77 sends a 512 bit PRNG every second and in hand-run testes I have > been able to determine the peak of the correlation with precision which > is 100-500 times better than the second to second jitter on the 1200km > propagation. > > -- > 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. ___ 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] Timing over low bandwidth channels
In message <20101209105031.6104c800...@ip-64-139-1-69.sjc.megapath.net>, Hal Murray writes: >Is there a similar sort of high level picture about sending timing info? I'm >not even sure what the units are. Basically with timing you only send one bit: "now" The most precise way to send that bit is to use a very long PRNG spreading code, and identify the correlator output peak using statistical estimation on the slopes up to the peak. DCF77 sends a 512 bit PRNG every second and in hand-run testes I have been able to determine the peak of the correlation with precision which is 100-500 times better than the second to second jitter on the 1200km propagation. -- 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.
[time-nuts] Timing over low bandwidth channels
> If you can indeed track a 1W signal from ~ Colorado, there might indeed be > some timing use for the system. I have a start at understanding how much data you can get through a channel. There is a tradeoff between data rate and error rate and it depends on the signal/noise ratio. Is there a similar sort of high level picture about sending timing info? I'm not even sure what the units are. -- These are my opinions, not necessarily my employer's. 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] Got 60HZ?
Hello, On Thu, Dec 9, 2010 at 5:13 AM, Michael Poulos wrote: > Recently I bought a Efratom Ru frequency standard from eBay and a frequency > divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a 1HZ output. > Today I thought of a way to make a nice 60HZ so you can use a mains-powered > clock for the display (using amplifier and transformer wired "backwards"). > But, now you'll need 60HZ. A European has it easy with 50HZ as you use a > BASIC Stamp or Arduino to divide the 100HZ output. But for 60HZ I came up > with a solution: > > You set up the Arduino to take the 10KHZ from the divider chip and program > it to count off 83 pulses to flip an output. But wait! Unless you add a > "leap count" every 3 flips of the output, it'll run fast. Assume at the > start the Arduino output starts high then turns low: > > (83+83+84+83+83+84)*20 = 10,000 pulses = one second > H__L__H__L__H__L > > Every output cycle and a half the voltage swing is a little over 1 percent > longer because of the leap count. This means that the distortion adds a > slight inaccuracy, not enough to upset New Year's revelers. But if you want > a better 60HZ, try using the 100KHZ: > > (833+833+834+833+833+834)*20 = one second > > You see where this is going with leap counts. The ultimate of course is one > really good Arduino and (after a hex inverter to amplify it) take the > straight 10MHZ and apply this leap count technique: > > (8+8+83334+8+8+83334)*20 = one really accurately made 60HZ = > one nice second, just the thing for a Nixie clock. :) > > Now, what is a good hex inverter to take the 10 million HZ of my rubidiom > movement to feed a frequency divider chip (and later Arduino)? It needs to > take the .5 of a volt sinewaIe and squarewave it and in a normal 14 pin DIP > (breadboardable) package. if you are not afraid of a little microcontroller programming, why not use a software DDS approach like this: http://www.myplace.nu/avr/minidds/index.htm it can output a nice sine wave at 60 Hz (or whatever) from say a 10 MHz clock really easily and the frequency is also easily tunable in software. I built several similar low frequency (audio range) software DDS using AVR and other microcontrollers. I usually add a one or two stage active low pass filter after the R/2R network. I also used to build the R/2R network out of selected 1% 10K resistors, final resistor match is usually good to 0.1% tolerance, but in some boards I just put 5% parts. Software is basicly an adder and you use the highest byte as a pointer to the ram or rom waveform samples, once you understand how it works, it's really easy to adapt to your needs. Usually the waveform you obtain has a DC offset, but that's easily solved too. Hope it helps. Frank IZ8DWF ___ 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.
