wrote:

I bought a new Sangean ATS-803A a long time ago, around 1989 I think,

[snip all the rest]

That was a highly regarded radio. It always got favorable remarks in
Passports from the 80s.

Its (more or less) successor was the Sangean ATS-818 or Radio Shack
DX-390, RS, SKU 200-0214 or 20-214. The same radio with a built-in
cassette recorder was the ATS-818ACS or DX-392, RS SKU 200-0219 or
20-219. A revised version had the SKU 20-219A.

http://www.google.com/search?q=dx-390

Note that static damage is the topic of the second hit.

It wouldn't surprise me at all if you could use a DX-390's owner's
manual to figure out the operation of the ATS-803A/DX-440. So let's try
that Radio Shack page "RadioShack DX-390 AM/FM/Shortwave Receiver
(200-0214),"
http://support.radioshack.com/suppor...onics/8186.htm

The "Operation" link,
http://support.radioshack.com/suppor.../doc3/3609.htm
looks especially interesting. See if that works for you.

Best wishes.