[RFtech53]

Ed, that would make sense.  I'm thinking you are correct.  I should have included the schematic ... which I'll do here. Do you see it in the schematic? 

I'm thinking it's the dotted line ground symbol that says "used in Model 38-7 only".  Though I still don't understand what it really does.  When it gets warm enough,  it grounds that line??

Aaron, I just replaced the 'ratty' rubber power cord with the new cloth covered one.