[R-390] need help with R-390A symptom

[wli]

Bob:

I had the same phenomenon occur in my R-388 last year. 

In addition to all the possible areas that could cause your symptom suggested by others re your problem... you might want to consider causes OUTSIDE the unit. In my case, it was my outboard antenna tuner... which had developed an internittent internal short. I found this out when I bypassed the tuner. Very bizarre.

W. Li