John Spigel,

I have recently repaired two 1000Ts and am fighting with an MPC 1000. All Doverons are basically similiar.

The mark and Space tuning, the filters, etc are all the same.

It helps to have a decent oscilloscope and a handful of 741 opamps for substitution.

I believe you said you have a 1000T. If you want to key a loop with it you must use a polar relay (255A - tricky to adjust) or if you can find one, a 314A which needs no adjustment. I connect my relay to the +/- 12 volt output and use it  to key an external 60-mil loop. The 'scope will show you if you the polar outputs are working before you connect the relay.after that the relay chatter will prove they are working.

My problem with my MPC 1000 is that the signal loss light flickers on space. When signal loss is activated it ties the unit up in mark hold. Mine works fine on the bench but acts up in the rack. I am stumped!

Tom   N3CRK