The Scout about which I have been enquiring showed a very unusual issue after I
had replaced the final transistors (at the request of the customer).
I did my usual ohmmeter reality check on all transistor pins just to ensure
there were no shorts anywhere. I was surprised to find that one final
transistor base showed the proper 100 Ohms to ground while the other one was >2
megohms to ground.
I traced this through the PC board back to the balanced transformer that
supplies the RF to the finals and found an open circuit between the top half of
the PC board and the bottom.
No amount of solder reflow corrected the problem so I passed a piece of wire
through the hole in the PC board that is supposed to make this connection,
soldered both sides, and things were now fine.
I suspect this was the actual root cause of the customer’s issue with the
radio’s output power.
Oh well, at least he now has new finals instead of 40 year old ones…
One for the books.
Gary
W0DVN
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|