Re: [time-nuts] HP E1938A question

The main issue is that the oven will no longer be at the crystal turnover temperature. If you are using it in a benign environment, you might not need the extreme thermal performance enabled by being dead nuts on the turnover. You still have an oven with thermal gain in the 100's of thousands.

Re: [time-nuts] Frequency counter questions

On Sun, Apr 23, 2017 at 6:25 PM, Jerry Hancock wrote: > > > So to summarize, if I limit my high resolution to 99,999,999.999hz and use > a gate of 1000 seconds, would that get me to .01hz? If not, then what > would the possible resolution be? > It is best to keep this kind of

Re: [time-nuts] Frequency counter questions

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

Re: [time-nuts] Frequency counter questions

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

Re: [time-nuts] Frequency counter questions

Hi > On Apr 24, 2017, at 3:49 PM, Chris Albertson > wrote: > > On Mon, Apr 24, 2017 at 10:13 AM, Bob kb8tq wrote: > >> Hi >> >> Some of the process below is “not trivial”. One example: >> >> You have a “gate” from the GPSDO and a “signal” from

Re: [time-nuts] Frequency counter questions

Orin, Thanks, this goes beyond interesting and I don’t know how you found it. I’ll be staring at this doc for the rest of the week. I have a dozen or so of the Nucleo boards around include the high end F7 types so I’ll see if I can duplicate their code on the System Workbench they reference

Re: [time-nuts] Frequency counter questions

kb...@n1k.org said: > You have a “gate” from the GPSDO and a “signal” from somewhere else. > If you > want the STM to do the whole thing, the “gate” pin needs to get the job > done > in X +/- 1 cycles of the “signal” pin. Delay X (if it’s consistent) > isn’t > a problem.

Re: [time-nuts] Frequency counter questions

Bob, I have an STM32F769 disco as well as the Nucleo version. The big difference between the two is the LCD display on the Disco from what I remember. I’ll play around with the code this week and report back. ___ time-nuts mailing list --

Re: [time-nuts] Frequency counter questions

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

Re: [time-nuts] Frequency counter questions

Hi Jerry, See AN4776 on st.com. Section 2.6 looks particularly interesting. Orin. On Mon, Apr 24, 2017 at 12:06 PM, Jerry Hancock wrote: > This is an exercise more than anything. It started when I noticed the > counter in a 3586B I purchased was +1 count unless I dropped

Re: [time-nuts] Frequency counter questions

On Mon, Apr 24, 2017 at 10:13 AM, Bob kb8tq wrote: > Hi > > Some of the process below is “not trivial”. One example: > > You have a “gate” from the GPSDO and a “signal” from somewhere else. If you > want the STM to do the whole thing, the “gate” pin needs to get the job > done in

Re: [time-nuts] Frequency counter questions

This is an exercise more than anything. It started when I noticed the counter in a 3586B I purchased was +1 count unless I dropped the input frequency .25hz. I was using my GPSDO reference for it and the 3336 it was counting. I then took my GPSDO and tried reading that directly and I see the

[time-nuts] HP E1938A question

I've just received an Ebay purchased E1938A, haven't tested it yet although I do have a 14 day return option, but unlike previous purchases of these the serial number label is missing from the rear of the PCB so I have no obvious way of knowing if the crystal is matched to the PCB. Does

Re: [time-nuts] Frequency counter questions

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

Re: [time-nuts] Frequency counter questions

Jerry, for a 100MHz PIC based counter a prescaler will be necessary. But it will not be necessary for a 30MHz counter. Prescalers do not have to be by divisors of 10. I recall the PIC counter input to be good to 50MHz so the prescaler could just be a divide by two if you need a 100MHz counter

Re: [time-nuts] Frequency counter questions

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