Ernie wrote:
In addition, if I inject a 9 MHz signal to the grid of the 1st IF
transformer, I get lots of
signal from the plate. But if I inject a signal to the grid of the 2nd IF
transformer, the signal level from its plate is very low. Ordinarily that
would mean the tube is defective, but it's not. I've swapped two NOS tubes
(that all test well on a reliable professional tube tester).I've checked
that IF amp's bypass caps and load resistors. Nothing.

I'd be much more apt to suspect the IF transformer (or the ceramic cap
used to peak it) rather than the tube. Still, I'd check plate and cathode
voltages on the tube to make sure they're realistic.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."