Newell its all a gamble at this point so go with the 6V and see if you gain a few hz. Its a serious cheat. But it just gives you a sense of how bad is bad. Does a olid volt maybe move you 1 hz or 5 hz? In the can you could actually look at the crystal and in general several caps around it. One of those caps either increasing or decreasing will shift the oscillator into range. I have had to do that some time ago on a oscillator. Granted it was a old piece of test equipment. Regards Paul WB8TSL
On Mon, Jan 11, 2021 at 11:01 PM Scott Newell <[email protected]> wrote: > At 09:01 PM 1/11/2021, paul swed wrote: > >Can you see what the xtal unit actually is. > > Trimble "73090". > > > >I suspect there is not a hole to a trimmer cap. But potentially if you can > > I peeled the sticker from the top--no holes hidden there or on the four > sides. > > > >open it you could get to a cap or at least see the xtal and what caps are > >around it. > > The can is partly soldered--not a full seam around the lid. It might > be possible to open it up without too much damage. (Looks easier that > the MV89 I opened years ago.) > > > >Other more difficult approach is to insert a purposeful offset. Maybe 6 V > >very current limited. Opamp would be the best way to do that. Just to see > >if you can pull it to 10 MHz. > >But it would also mean you have traced the efc control pin to some extent. > > The EFC trace on the GPSDO board is accessible and wouldn't be hard > to cut. EFC swings it about 8 Hz right now, but I'd need another 4 Hz > or so. Not sure 50% is doable. > > > -- > newell N5TNL > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
