SB-101 1st IF cathode resistor question
Randall C. Iliff
riliff at COMMSPEED.NET
Thu Mar 20 00:07:53 EST 2003
Greetings fellow Heath fans,
I'm still chasing the SB-101 low output on SSB, low S Meter reading
gremlin(s?) and came across something odd:
The schematic and circuit description show two 47 ohm resistors (R104 &
R105) that form a voltage divider in the cathode to ground path of 1st IF
Amp V3. The resistance chart shows an expected 105 ohms from the cathode
(pin 7) to ground.
The assembly manual shows to place 66 ohm resistors at those locations, and
that is what is currently mounted on the board. I read around 150 ohms to
ground across that path, and considering the minor parallel resistance of
the metering circuit, infer that the resistors are on the high side. Screen
voltage on pin 6 of V3 is a bit high (195 versus the manual reference of
180).
Anybody remember this issue? Should I care one way or the other?
Thanks again!
Randy
(KE0BN)
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