[R-390] Detector tests followup

[n4buq at knology.net]

> Checked 6 ohms for both windings; however, I don't get infinity between 
> coils when the deck is connected to the main harness.  If I disconnect 
the 
> diode load, the windings show infinity between them so something 
downstream 
> of the diode load is providing a high-resistance between the windings 
> (about 50k).  I notice this varies a bit when turning on/off the 
limiter.  
> Perhaps the circuit ties back from the centertap of the primary back to 
the 
> limiter.  I briefly looked into that but was on my lunch break and didn't 
> look at all the places where this could provide a high-resistance shunt 
> between the primary and secondary windings.

Okay, did a little schematic reading and see where there are paths from 
both the primary and secondary to ground through a series of resistors so 
with the main plug and the diode-load connected, there should be some 
resistance reading between the primary and secondary of T503.

Perhaps I do need to do some tube-swapping.  I thought I had a good one in 
there but maybe not.

Barry - N4BUQ