Hi Often the "oven ready" signals are actually a "oven not broke" signal. They may be of little use if the idea is to only switch once the OCXO is significantly more accurate than the TCXO. The lock signal on an Rb is indeed quite adequate for this task.
Bob On Dec 9, 2012, at 5:36 PM, Tom Miller <[email protected]> wrote: > Some of the HP OCXOs (the one in the HP856x SA) have a "oven ready" signal. > That could be used to force the switch. Some Rubidium standards (FEI FE-5680A > for sure) have a locked indicator that could do this function. > > I think you could mute the 10 MHz where it is fed to the instrument and that > should default to the internal source. > > Tom > > ----- Original Message ----- From: "Joseph Gray" <[email protected]> > To: <[email protected]>; "Discussion of precise time and frequency > measurement" <[email protected]> > Sent: Sunday, December 09, 2012 5:21 PM > Subject: Re: [time-nuts] Switching oscillators > > > My first thought is to simply wait a fixed time until the OCXO has > warmed up and then switch over. I thought that others here might > suggest a better method. > > Joe Gray > W5JG > > On Sun, Dec 9, 2012 at 3:04 PM, <[email protected]> wrote: >> You would probably want to see when the external oscillator frequency is >> close to the internal oscillator. I suppose than could be done with a mixer >> and glue circuitry. I don't think this is cheap though. >> >> >> -----Original Message----- >> From: Joseph Gray <[email protected]> >> Sender: [email protected] >> Date: Sun, 9 Dec 2012 14:12:51 >> To: Discussion of precise time and frequency measurement<[email protected]> >> Reply-To: Discussion of precise time and frequency measurement >> <[email protected]> >> Subject: [time-nuts] Switching oscillators >> >> I have a device that has an internal TCXO. I want to feed it with an >> external OCXO, but I don't want to completely replace the TCXO. >> >> Here is the scenario. On initial power on, or after a power loss, I >> want the internal TCXO to be used. Once the OCXO is up, I want to >> switch to it. How could this be done easily and cheaply? >> >> Joe Gray >> W5JG >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
