Re: [time-nuts] Z3801 Update with VP-Oncore 8Ch receiver

Art - Good to hear about a uBlox SSR-6 based board. A number of products (GPSDO, time servers, etc.) used that Motorola board set. I was following Dan Watson's work on building a substitute late last year ... a modern Oncore VP replacement / interpreter using the new u-blox chipsets.

[time-nuts] OCXO Retrace

I've been running up a number of OCXOs lately, all Trimble 34310-T. For most of them, the DAC moves in the negative direction after lock. But there are a few where the DAC moves more positive. Is this an indication of a different cut of crystal, or is retrace direction more or less random?

Re: [time-nuts] OCXO Retrace

Hi Tim, This is with the GPSDO that I designed. It uses a PLL which is corrected for sawtooth. The receiver is an LEA-6T. I've noticed that a few of these OCXOs continue to retrace upwards in DAC movement, even after a number of days. I haven't run any of them for more than a week, as I've

Re: [time-nuts] OCXO Retrace

I think what you are observing, is the detail of how the control loop transitions from frequency locked to phase locked. And this has more to do with the divider chain reset and phase detector than anything else. Note that several of the hobbyist/E-bay GPSDO's (especially the "Chinese GPSDO") do

Re: [time-nuts] 2016 European Frequency and Time Seminar

Hi Hmmm …. flea market … so how do I drive there from here with the truck(s) ? For me, there appear to be a few issues beyond them simply deciding to have one.:) Bob > On Feb 9, 2016, at 4:06 PM, Poul-Henning Kamp wrote: > > > In message

[time-nuts] Z3801A Internal A/C Supply ??

OK if you followed the previous thread on this unit you will remember that the front half of my supply the reverse polarity and under/ over voltage switch is bad but the DC-DC converter half of the supply is good. I initially cut a trace and rerouted the power input to bypass the voltage

[time-nuts] Science of Time, registration is open

Early registration has opened for The Science of Time to be held on the Harvard campus from 5-9 June 2016: http://sot2016.cfa.harvard.edu On 10 June there will also be a special tour of the Harvard Scientific Instrument Collection. The program should have plenty to interest anybody

Re: [time-nuts] OCXO Retrace

Hi Charles, I'll see if I can figure out which of these is retracing the "wrong" way and put it in a unit. I'll let it cook for a couple of days and then post a plot. Like I said, these are all Trimble 34310-T, though I know that there were at least two manufacturers for that part number.

Re: [time-nuts] Z3801A Internal A/C Supply ??

Dave wrote: Should I be concerned about. 1) Noise from the supply or the A/C lines now inside the box Yes, you should always be concerned about both radiated and conducted noise generated by switching supplies, inside or outside the enclosure. Personally, I would never run the output

Re: [time-nuts] OCXO Retrace

Bob wrote: I've noticed that a few of these OCXOs continue to retrace upwards in DAC movement, even after a number of days. I haven't run any of them for more than a week, as I've built only a limited number of these units. The normal situation is to retrace downward from the start, once