Some of the 1970's era stereos I've recapped have had glue like stuff under the bigger caps. I assume that it was to hold them in place while they were soldered by the automated machines. Some of them had corrosion under them, some not.

I'm wondering if there's a common source of interference like lights, computers, etc. causing this. Does going to a half wave antenna change it? I'm curious as I just ordered a Standard agile modulator, so I'll see what it does. I was looking for a fixed channel 6 one thinking that I could also use it for FM radio since we don't have a station at 87.7 around here. But, they were too expensive or were mini rack ones that need a power supply.

It seems the Drake ones have gone up in price too since Bob did his first video. I guess that's the power of his videos! Please just don't do any on Pico, or Scientific Atlanta, or Holland, etc.!