[Boatanchors] Johnson Navigator VFO Question

[whitebear1122 at comcast.net]

Hi, I'm troubleshooting a problem with my Navigator and have a question or
two.  What is the purpose of L12, the variable inductor hanging off the VFO
6AU6 plate?  

 

I'm chasing down an odd observation between the VFO and buffer.   On the
6AU6 pin 5 plate output there is the fundamental 1.8 MHz as there should be
but there is also a harmonic around 3.5 Mhz.  Where in the heck would that
come from I wonder.  That's what I'm hunting for now.

 

Thanks.  73, Scott WA9WFA