1981 13" Magnavox 13C108?

[dieseljeep]

I picked up this set as a freebee, at the Illinois Antique Radio Club, swapmeet a few months ago. The set is a very low hours, super clean set that has a great picture.
The only issue with it, is when playing a video tape, it flagwaves like mad!
A set built that late should play a video tape with no problem.
I wonder if there's information around about changing the horizontal AFC time-constant.
I appears that the set is all original and never needed repairing.