Outstanding problems

Have uniden supra that keeps going off frequency. Set left hand and
right hand audio frequencies as noted in billboard before programs and
also from Mr Video's Wildfeed video listings. Unfortunately the
receiver drifts off frequency and sound is off. No local facilities to
adjust problem and nearest repair place is way out of town.  Any way I
can eliminate problem myself? Off air taping no longer possible. I.E.
When I am at home, I have audio set for particular transponder at
6.2.x6.8 ,tune in and sound is off frequency, so I go to 6.21 and then
back to 6.20 and sound is clear or go opposite way to 6.19 and then
back to 6.20 and it clears up. Can't do that when I have unit set to
tape when I am not at home.