[Ron Ramirez]

I've had plenty of trouble with Type 75 tubes. I have had some of these which make noises like a thunderstorm which, unlike your experience, Steve, grew worse as the radio warmed up.

With this last 75 tube I put into the 18B, I removed the solder from the grid cap and then applied new solder. That has cured the problem for me in the past on many - not all, but many - of the offending Type 75 tubes. I had not done that with the first two 75 tubes I tried in this 18B. You know how it is when you are in a hurry...and I wanted to finish up this radio since it was Christmas Eve.

The first two 75 tubes exhibited a different symptom - the volume would drop slightly and the tone would change to a deeper sound. I really didn't think it was a tube problem, but after changing the 75 for the third time - and desoldering and resoldering its grid cap before installation - so far, so good.

And yes, every paper and electrolytic capacitor has been replaced including those in the tone control, as well as all but two of the resistors. One is the big "B-C" bias resistor, the other is attached to the band switch so it does not affect the audio circuit.