Hi Ken,

Ken Fowler wrote:

Hi Frank,

The reason that it suggests to inject the 467 KHz IF signal into the mixer
grid is that the tube will serve as a capacitive coupling for the signal
into the IF amplifier. If you try to inject at the mixer plate, you have to
worry about the high voltage at that point. If you can hear an output with
the signal injected into the mixer grid, the IF amplifier is working. Then
you can inject the 4.6 MHz signal to see if the mixer is working. If the
second mixer is working, move back to the grid of the first mixer with the
4.6 MHz signal. Etc. Etc. Of course, it would help to know what level of
signal at these points should cause a normal output. Good Luck and watch
out for those plate voltages. In fact, it is not a bad idea to check the
DC voltage on the control grids. If the voltage is positive, it might mean
a leaky coupling capactior.

thanks for all suggestions, I'll check the voltages on the grids first of all,
even if capacitors should be ok, all tests I made showed no leaks on them, but
I didn't test *all* of them as some are difficult to reach.
I haven't been able to find either a DC voltage chart or an RMS signal chart
for this receiver, so I guess it won't be an easy troubleshooting.

73
Frank IZ8DWF