Hi Ok, so that’s phase modulation and not frequency modulation. Simply put, it’s not a high level signal into the EFC. It’s also not anything inside the oscillator loop. Normally the best way to do a broadband phase mod like that is to feed a signal into the input of the output buffer. I’d check it with a couple of different loads and see if that chip sings when loaded this way vs that way.
Bob > On Feb 27, 2016, at 4:18 PM, Rob Sherwood. <r...@nc0b.com> wrote: > > Here is a look at the spectra. 6.3 kHz span, 7.6 kHz resolution bandwidth. > I have a 1.6 MB file with better resolution, but I assumed that would never > make it through the reflector. > Rob > NC0B > > -----Original Message----- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp > Sent: Saturday, February 27, 2016 12:25 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Inside a CTS 1960017 OCXO > > > > Hi > > The controller shown on the PC board is not a chopper. The only reason you > would be getting 60 Hz is that somebody did an “aw shucks” and left a part > off the board. I suppose they could have left a part off (or put the wrong > part on) on whole batch of them. I’d make sure it still does it with a big > bypass (100 uF tantalum) on the supply right at the OCXO before I gave up on > the parts. > > Given that it’s China, those parts may not have any relation at all to the > CTS we think of over here (regardless of how they are labeled). Internal > workmanship and design suggests that they did come from CTS. > > Bob > >> On Feb 27, 2016, at 12:35 PM, Rob Sherwood. <r...@nc0b.com> wrote: >> >> Hi Dan, >> >> I purchased two of these, and VA7OJ one. One of mine is defective, and the >> seller is going to replace it. What was disappointing was all the spurious >> at 60 Hz intervals relatively close-in to the 10 MHz carrier. I suppose if >> all one wants is a reasonably accurate 10 MHz, then they work OK. My good >> one and Adam's unit were 1x10^7 low in frequency once warmed up, and there >> are pins for frequency adjustment and sync to another standard. However if >> one wanted it for an oscillator with good close-in phase noise, the spurs >> ruin that hope. >> >> Do you know if there is a chopper at 60 Hz that runs the proportional oven >> that is the source of all the spurious? >> >> Rob >> NC0B >> >> -----Original Message----- >> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of >> Daniel Watson >> Sent: Saturday, February 27, 2016 9:48 AM >> To: time-nuts@febo.com >> Subject: [time-nuts] Inside a CTS 1960017 OCXO >> >> >> >> Hi, >> >> I'm sure many of you are tracking the cheap CTS 10MHz OCXOs available on >> eBay right now. I purchased a case of them, and decided to crack one open. >> I took pictures along the way, thinking that might be interesting to the >> list. Here is the blog post if you are interested: >> >> http://syncchannel.blogspot.com/2016/02/10mhz-ocxo-teardown-cts-196001 >> 7.html >> >> Comments on the internal construction of the OCXO are welcome. It seems >> pretty straightforward inside though. >> >> >> Best regards, >> >> Dan W. >> _______________________________________________ >> 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. >> >> >> >> -- >> If this email is spam, report it to >> https://support.onlymyemail.com/view/report_spam/ODExMjI6MTg1NzM0MDA3N >> Tpyb2JAbmMwYi5jb206ZGVsaXZlcmVk >> >> _______________________________________________ >> 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. > > > > -- > If this email is spam, report it to > https://support.onlymyemail.com/view/report_spam/ODExMjI6MTg1NzM3NjUwNDpyb2JAbmMwYi5jb206ZGVsaXZlcmVk > > <Narrow-1a.jpg>_______________________________________________ > 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.
