[Boatanchors] HX-50 UPDATE

[John Lawson]

On Tue, 14 Jun 2011, Bill and Liz McHugh wrote:

>
> Im running out of ideas here....can't quite reconcile myself to the fact 
> that all five crystals could be blown.
>


    Looking at the schematic (courtesy of edebris/bama) - perhaps check to 
see that c224 (2 uF) and R160 (6.8K) are good. I'd be especially leery of 
C224 - if it's leaky, especially under load / heat, it'll short the grid 
circuit to the cathode by the amount of leakage it presents. C224 is 
between pin 1 and pin 2 of V103b (the 6AW8A osc)

   Secondly - long shot - is S102E in mechanical 'sync' with itself? Has a 
rotor plate slipped? Is the front section really dirty/grungy? The osc 
grid is attached directly to the switch wiper, and it's very high 
impedance there - won't take much to provide a DC leakage path that way.

   Lastly - how about C150 (6uF). Good? Leaky?  although if it was bad it 
would completely cut off the other half of the 6AW8 and kill the signal 
flow thru the reciever. Whats at "Test Point B"?



> Any comments or ideas appreciated.  Anyone have a junker HX-50 with known good crystals?
>


Cheers

John KB6SCO