[GreenKeys] Dovetron Repair

[W2HX]

Yikes. Someday this MPC-1000C needs a turn on the bench. I worry what I will find. Already there is a wire with ¼ inch plug emanating from the LOOP jack. I wonder what else is in store for me…

https://w2hx.com/?prefix=x/RTTY/Dovetron/MPC-1000C/


73 Eugene W2HX
My Youtube Channel: https://www.youtube.com/@w2hx/videos


From: greenkeys-bounces at mailman.qth.net <greenkeys-bounces at mailman.qth.net> On Behalf Of Tom Hunter
Sent: Monday, February 12, 2024 8:25 PM
To: GreenKeys at mailman.qth.net
Subject: [GreenKeys] Dovetron Repair

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
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