Did do some more reading and I think what I suggest is the right approach. Band 2 and 3 use the same VCO. So if band 2 is generally working then its possibly the rf multiplier yig filter mixer diodes etc. But if the RF detectors show RF then its going to be a much more interesting issue. I do not know what sort of test equipment you might have. I have spectrum analyzers and such. And do agree without extenders that I don't have its a royal pain. Regards Paul.
On Fri, Dec 7, 2012 at 9:52 AM, paul swed <paulsw...@gmail.com> wrote: > Chris > So you also must run the gatesgarth website. I was thinking there might be > other good tidbits. The EIP manual was nice. Good job on the control signal. > I had a chance to reread the theory of operation yesterday (Well parts) > and if band 2 is now working by cheating at least, then it would be > interesting to look at band 3 and see whats going on. > There seems to be 3 variables that control operation. 1 you have > experimented with the next is the band 2 or band 3 selection and then the > 3rd is how the system searches for a signal in either band. > This seems to be a diode detector in the front end and a diode detector in > the IF. When a signal is detected at the front and the signal in the IF is > larger the system says I have a signal in the correct down conversion band. > The operational logic diagrams are far more clear. > So the trick in band 3 would be to look at the IF rf diode and see if it > ever has a voltage. That would give a hint as to what direction to look in. > Sure you could look at the LO with a spectrum analyzer and see if it was > correct also. You just might not have one. :-) > Regards > Paul > WB8TSL > > > On Fri, Dec 7, 2012 at 5:22 AM, Chris Wilson <ch...@chriswilson.tv> wrote: > >> >> >> >> >> >> <SNIP>______________________________________________________________ >> >> > This is where I am now, I hope the above makes some sense if >> > viewed with the service manual and the schematics. Thanks. >> >> >> >> >> 07/12/2012 10:17 >> >> Latest update: >> >> Removed Q12 from board A109 and put a 1k resistor across vacant >> emitter and collector board holes, thus putting 12 volts into the >> mixer to switch it externally. Counter now works perfectly on Band 2 >> and I followed the signal path from R2 / R3 junction (wrong impedance, >> but a reference nonetheless) through to the anode of CR3. >> >> Hopefully self explanatory with regard to file names, scope patterns >> are at http://www.gatesgarth.com/scope/scope.zip >> >> Pretty stuck as to where to go next now. >> >> >> >> -- >> Best Regards, >> Chris Wilson. >> >> >> _______________________________________________ >> 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.