Going backwards

[halfwatt959]

I have an old royce 1-620 base keys 4 drops to 3 when you talk. Have used up my small store of knowledge. Any ideas will be apreciated. Most would say a 23ch aint worth fixing but I'm trying to restore it just because I like old junk. Thanks for any tips on where to look. I know its not over modulating, never been tuned. So I'm at a loss as to what to check next.