[Johnson] Johnson Valiant Zero Beat Tone

[richard]

Hello.
I have a Johnson Valiant that has lost the Tone for the Zero Beating it has it on 20 meters but not on any other band and I am not sure where to start to look so if someone can give me a good direction to start and try to walk me threw what to look for & do that would be Great & know I am not a TEC of any kind I just picked this Transmitter up and am trying for what little I know to get it back on the Air. I do have the Manual but it really is not any help that I can find.. I have read that the Side Tone Oscillator has something to do with the zero tone but where is that on the Valiant?.. So any Help would be Great.
Thanks Much
 Richard

Richard Morris