niteviser wrote: > Hi Ed, > > The differences I see between the -25 and -26 are minor. Caps and resistors > in the Low Pass Filter audio stage and a different 12.8Mhz reference with a > voltage tuning pin, where the standard didn't have it. The specifications of > the reference are same otherwise, 1ppm -20 to +70. If you are going from -25 > or -26 to -20, just change the components to the -20 values. Yes, they were > defined changes for FCC, according to the book. > > niteviser
Aha. Any chance of a PDF with the -26 documentation? What pin on the DB25 is the tuning pin brought out to? I also assume the voltage tuning pin needs to be tied to a stable reference. The series II schematic shows the "FM" pin (VCXO adjust) tied to a divider from +5V (not the most stable reference point). Thanks, Ed Yoho W6YJ
