[Central-Electronics] 10B harmonic problem

[Arthur Delibert]

Hoping somebody can help me with this problem, which I didn't see anywhere 
in the archives.

I am a new owner of a 10B -- actually 2 of them, and they both have the same 
symptom.  When I use the 458 VFO on 20 meters, there is a very strong 
harmonic at 3 times the VFO freqency, or about 15,500 MHz.  The manual says 
to expect this, and to tune L6 for a minimum output on the harmonic.  It 
says the harmonic should be only a few percent of the 20M signal.

I have a harmonic that's as strong as the 20M signal, and tuning L6 through 
its whole range does almost nothing to eliminate it.

Using a grid dip meter on L6, I can see some dip at about the right 
frequency.

I'm using the same VFO and the same 20M coil on both of my 10Bs.

Is my 458 VFO hyperactive, and generating a much bigger harmonic than it 
should?  Have the components in the 15 MHz trap drifted in a way that the 
nulling action is in the right frequency range but isn't very prominent?  
Something else?

Any help or thoughts appreciated.

Art  KB3 FJO