First of all, mystery solved – the remote enable input for the IF attenuator. After quite painful tracing of wires and disassembly of the logic boards, a broken trace! Just a little crack, but big enough to block the electrons’ flow. A little bit of solder, and then, suddenly, the MSR-904A’s IF attenuator can be remotely controlled.

Today, a also the dual pot for the F2 adjustment arrived – fitted, also this, working again.

But most interesting, a little box, with a label not seen before:

The part has a NSN number, original unit price was no less then 71.38 USD!

Enclosed – the most special mains power cable I have ever seen:

-it was well packaged in a multilayer heat-sealed bag.

And, a label, which will be kept – Federal Prison Industries: Escape Proof Guarantee