Skip previously in these threads there was a direct real analog control that was discovered. I have used it and it works well. The thread describes how to get to it. Regards Paul
On Sun, Jan 29, 2012 at 11:22 PM, Skip Withrow <[email protected]>wrote: > Hello Nuts, > > I've been trying to get the analog EFC to work on the FE-5650A (a very > close cousin of the FE-5680A). On these oscillators it is normally on > pin-8 of the DB-9 (Option 12 and 30). As one of the serial lines is on > this pin, I traced the jumper that is placed for the EFC option(s). > However, changing the voltage on the pin does not seem to move the > frequency (or at least not very much if it does). Anybody know the nominal > EFC sensitivity of the 5680? > > On tracing things further, I have found that this input goes into the (4 > channel) A/D associated with the microproccesor. Changing the voltage > gives a value in message 5A that also changes a corresponding amount. The > EFC bytes are bytes 5 & 6 of the 5A message, first byte is low second byte > is high. Appears to be 12-bit value (0FFF max). > > The question is - how do you enable the EFC? Maybe it is a bit that has to > be set in one of the other messages. (But then how does the uP communicate > the EFC value to the physics package?) It (more likely) may be that I have > not found the true C-field control circuitry yet and the A/D is just a > monitor. > > I recall someone implementing C-field control on a FE-5680A with the pot > disabled, but cannot find it now. If someone can point me to that post I > sure would appreciate it. > > Thanks in advance. > > Regards, > Skip Withrow > _______________________________________________ > 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.
