On Wednesday, August 1, 2018 at 10:21:54 PM UTC-7, Fotopiggie wrote:
Thanks for the response. Yes it's consistently roughly
5 kHz below the designated frequency. For example if I
want to tune in 11815 kHz I need to key in 11810 kHz to
hear the signal (not perfect, still need tune up a bit
with fine tuning dial) I don't know the exact amount of
the frequency off as you may know the radio tuning is
in a 5 kHz step.
So if IF alignment is the case I don't think I can
handle the job. May need to find a technician to do the
job...
Was it like then it was new? If so, it may be a manufacturing error. IF filtering is often done with ceramic resonators, and if they used 450 kHz instead of 455 kHz (or vice versa), that could explain it. It is unlikely that it would have spontaneously shifted frequency. I tried to look at the circuit diagram that Frank cited, but my eyes are too old and the my monitor resolution is too poor for me to read it.