Curt -
If this is a 'new' transmitter to you, the most likely cause of a crispy R61 is that someone shorted
one of the trimmer caps in the PreSelector plate circuit to the chassis. Easy to do, especially
when guys use a metal screwdriver to adjust those trimmers through those little holes. Only takes a
momentary short to do it!
R21 and R26 are also subject to this problem!
Of course a Plate / Suppressor short will also do it, but those don't usually
'clear' after a failure.
--
73, Garey - K4OAH
St Charles, IL
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>
[email protected] wrote:
Well, my nose detected burnt smell in vicinity of T4. R61, a 150ohm 1/2
resistor in the 250 volt line to V8's plate is burnt to a crisp, resistance is
zero. But why? Resistance to ground on V8 pin 5 is 15k per spec. But pin 6
screen grid resistance to ground it 15k, vs 90k spec.
Any advice? 73, Curt KB5JO
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