The Fisher 500t is an early solid state receiver. If the tuning knob turns but the dial doesn't move it could be the dial-string, or it could be that the tuning knob has a set-screw that locks it to the shaft. Look for a hole on the side of the tuning knob-should take a small allen-wrench.
If it is the dial-string, you can likely search for a dial-stringing diagram online.
There is almost always a diagram in the service manual, and you should be able to get one for free at the Vinyl Engine (I think that's the site name).
My thought on putting money into these guys is this: If you like it and want to keep it, go ahead and pay someone to get it right. If you're thinking about making it perfect and selling it for big money, the demand may not be there.
People seem to like these receivers so enjoy!
If it is the dial-string, you can likely search for a dial-stringing diagram online.
There is almost always a diagram in the service manual, and you should be able to get one for free at the Vinyl Engine (I think that's the site name).
My thought on putting money into these guys is this: If you like it and want to keep it, go ahead and pay someone to get it right. If you're thinking about making it perfect and selling it for big money, the demand may not be there.
People seem to like these receivers so enjoy!