Re: [time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Chris Albertson
My dim memory says there is some analog way to multiply the phase noise. What does that? Then it might be easier to measure. On Wed, Jun 12, 2013 at 2:36 PM, Marek Peca wrote: > My point was, that DSO is basically an ADC. Therefore, there is some >>> amount of noise, nonlinearity and drift,

[time-nuts] Spectracom 8170 Time of Day grief...

2013-06-12 Thread Burt I. Weiner
Paul, U... What a revolting development this is. My 9150-52054 have a smaller readout out that I can't see without climbing up on my bench, so I suppose I will no longer know what time it is. I've never really had to delve into the 8170 so I wasn't up to speed on how they derived the da

Re: [time-nuts] Unit tests for time calculations

2013-06-12 Thread Chris Albertson
I think it depends on you definition of "Unit Test". Some people do a "sanity check" time test just to verify the function works. Those who want a better test will use a code coverage tool and will add test cases untill every path through the function is exercised. One thing to remember is NO T

[time-nuts] New to list and GPSDO questions

2013-06-12 Thread Bob Stewart
Hello to the list.  I saw on K3PGP's site a mention that the UT-41 GPS receiver had a 10KHz signal on-board so I decided, why not build a GPSDO for my "new" HP 5334B?  Unfortunately the one I bought doesn't have a 10KHz point, and the board doesn't even pull out the 1PPS signal from the chip.  S

Re: [time-nuts] Unit tests for time calculations

2013-06-12 Thread Tom Van Baak
> 12/31/1998 00:00:00 EST + 5184001 seconds = Time Date in UTC > 01/01/1991 11:01 AM EST = XX/XX/ XX:XX UTC Doug, This is difficult (or impossible) to do right; at a minimum you need a table of all past, current, and future national timezone definitions, DST rules by locale, and leap secon

[time-nuts] Update on the d-psk-r schematic costas loop

2013-06-12 Thread paul swed
Good catch by Russ of time-nuttery fame. Wrong ground on the 74hc390. Updated schematic attached. Thanks Rudd Regards Paul WB8TSL WWVB dpskr Costas_Div nu 12Mhz 06122013.sch Description: Binary data ___ time-nuts mailing list -- time-nuts@febo.com To un

Re: [time-nuts] Spectracom 8170 Time of Day grief...

2013-06-12 Thread paul swed
Burt One other tidbit the phase mod will exactly cause what you see. Spectracom used phase tracking to demodulate the AM time signal. Thats why its nuts. On Wed, Jun 12, 2013 at 5:49 PM, paul swed wrote: > Burt > There is nothing wrong with your 8170. WWVB no longer allows it to work > correctl

Re: [time-nuts] Spectracom 8170 Time of Day grief...

2013-06-12 Thread paul swed
Burt There is nothing wrong with your 8170. WWVB no longer allows it to work correctly because of the phase modulation. They went to all psk about 1 month ago. They had been reverting back twice a day for things like the 8170. So the ole 8170 is dead. You need to build something like the d-psk-r to

Re: [time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Marek Peca
My point was, that DSO is basically an ADC. Therefore, there is some amount of noise, nonlinearity and drift, limiting the jitter measurement. Do you think any method can dig more information from given data than sinc() interpolation and zero-crossing computation? The cross-spectrum averaging

[time-nuts] Spectracom 8170 Time of Day grief...

2013-06-12 Thread Burt I. Weiner
My good old Spectracom 8170 is not setting time. I don't use it for frequency, just as a clock for my Hazetorium. I live about 20 minutes north of downtown Los Angles in Glendale. The antenna I'm using is the Ferrite Rod loop in PVC that came with the 8170. It's located on my back porch jus

Re: [time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Stefan Heinzmann
Marek Peca wrote: (..) I have tried it with a very cheap one, Rigol 2-channel, originally 50MHz, reflashed to 100MHz. 2 signals, ref&measured, into Ch1, Ch2. Waveforms (2x500Msps) acquired, sinc() interpolated. Results: short-term single-shot jitter around 100ps RMS. Long-term was of no intere

Re: [time-nuts] Unit tests for time calculations

2013-06-12 Thread Doug Calvert
On Sun, Jun 9, 2013 at 11:29 PM, Bill Hawkins wrote: > Hi, Thanks in advance. > > Since this is a list for precise things, could you make your questions > more precise? > > What sort of test cases? > > What sort of calculations? Do you mean conversions? > > What do you mean by "catching" a

Re: [time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Marek Peca
(..) I have tried it with a very cheap one, Rigol 2-channel, originally 50MHz, reflashed to 100MHz. 2 signals, ref&measured, into Ch1, Ch2. Waveforms (2x500Msps) acquired, sinc() interpolated. Results: short-term single-shot jitter around 100ps RMS. Long-term was of no interest for my purpose n

Re: [time-nuts] Ovenaire OSC 49-61C

2013-06-12 Thread Mark C. Stephens
Hi Fred, Also, I neglected to ask, you wouldn't have the OXCO pin outs would you? -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Frederick Bray Sent: Thursday, 13 June 2013 2:01 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Ovena

Re: [time-nuts] Ovenaire OSC 49-61C

2013-06-12 Thread Frederick Bray
Hi Mark, I am not sure about the design of your OCXO but recently I repaired an Ovenaire from a Cushman 5510 service monitor. I found that there was a bad trimmer pot in the oven control circuit. This wasn't apparent until I started monitoring the current drawn by the unit while trying to a

Re: [time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Stefan Heinzmann
Marek Peca wrote: Hello, given that digital scopes have a multichannel ADC for acquisition, which is similar to what a cross-correlating phase noise measurement instrument has, it occurred to me that phase noise measurement might also be possible with a standard digital scope and some post-p

Re: [time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Didier Juges
I would think that considering the amount of time it takes to get the data out of the scope (particularly on the cheap scopes) would be a major impediment to that method regardless of the cleanliness of whatever data you eventually get, since you will only be able to analyze a small fraction of

[time-nuts] Ovenaire OSC 49-61C

2013-06-12 Thread Mark C. Stephens
Anybody have service, schematics or experience for one of these OCXO? They are commonly seen in early HP 8566A spectrum analysers. It is out of adjustable range. Fortunately I had a spare OSC 49-61C floating about and replaced this off frequency reference with it. However the replacement tends to

Re: [time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Marek Peca
Hello, given that digital scopes have a multichannel ADC for acquisition, which is similar to what a cross-correlating phase noise measurement instrument has, it occurred to me that phase noise measurement might also be possible with a standard digital scope and some post-processing software.

Re: [time-nuts] +/- TI button on 5370B

2013-06-12 Thread Azelio Boriani
Not only HP counters. I have never seen a TI counter that outputs negative values. I use the cable delay or user delay feature of GPSes to delay one PPS to the other so that the result is always positive. I have seen that only oscilloscopes can handle negative time interval values. Maybe that the W

[time-nuts] Phase noise measurement with a scope

2013-06-12 Thread Stefan Heinzmann
Hi all, given that digital scopes have a multichannel ADC for acquisition, which is similar to what a cross-correlating phase noise measurement instrument has, it occurred to me that phase noise measurement might also be possible with a standard digital scope and some post-processing software

Re: [time-nuts] +/- TI button on 5370B

2013-06-12 Thread Bob Camp
Hi Another simple "solution" - If you are using a GPSDO as a PPS source, use the cable delay to offset the pps you are using as a reference by a microsecond. That's worked on every GPSDO I've tried it on. No it really doesn't solve the problem, it just covers it up. Post processing the dat