OK Ed, I have 2 files showing the PCB details with -26 variant info. They frequency reference is still kept totally internal. If higher stability or external reference is available, the internal is removed and a mini coax socket fitted to have a cable connected to have an input on the rear panel. I will put the pdf files in the files section. Look for T857 220-01398-02_-04.zip.
Al (niteviser) --- In [email protected], Ed Yoho <w6yj_ya...@...> wrote: > > niteviser wrote: > > Ed, > > > > The tuning pin is the FM pin of the 12.8MHz module. There were several 12.8 > > MHz references some with 3 pins and then some with 4 pins which used the > > half rail to set the frequency mid point. It was quite acceptable to > > program to the closest frequency on the Eprom and pull the reference either > > by altering the voltage or adjusting to get the offset. It is still then > > 1ppm stable. Can you tell me which PCB version you have 220-01398-??, I'll > > she what I have available. > > > > niteviser > > > > I don't have any of the -26 transmitters. It is more for my > understanding of how they are doing things (where they bring out the > tuning voltage on the DB25 or is it using the option DB15, etc.) and > what is required to fully modify a -26 to a -20. > > Ed Yoho > W6YJ >
