Fix the bending and waving images when playing beta and VHS tapes on your old TV

[old_tv_nut]

C106 and R156 are the main AFC loop filter components, in conjunction with R155.

I would try reducing the size of C106 first. How much is hard to say, but try 1/3 the size (about .05) first and see what you get. The bending should extend less down into the picture, but if it gets squiggly, then you need to play with the damping resistor R156.

This kind of modification is actually easily made by "decade box engineering." if you are observant. If you have a switchable capacitor box and a switchable resistor box, just substitute them for the C and R in the circuit, start with them set for the schematic values, and then note the effects of changing the values. It's wise to shut off the set before changing the switches, as you may have infinite resistance and infinitesimal capacitance between switch positions.

If you don't have decade boxes, the next easiest experimentation is substituting parts using clip leads - be careful that the connections are secure!