I have a Radio Shack PRO 2952 with a very irritating problem: after being on
for a while, it starts to go into an acoutical feedback loop. The only thing
I can do is turn the volume down, but I have to turn it down to the point
where I can barely hear it - or else turn it off for a while.

I thought maybe it was a problem with overheating, but I don't understand
the feedback problem. Any ideas what's causing this or how to fix it ? TIA
Maximus.

V