[R-390] R-390 Break-In Relay - Do I have a problem?

[k1jos at att.net]

I finally got my R-390 RF and audio working well with outstanding advice
from Don Heywood.  I just put it into the rack with help from a young strong
neighbor and I was setting up a TR switch/sequencer to use the radio with my
low power AM transmitter.  The TR/sequencer relays can handle up to 400V @
120mA.  I measured the current across the rear terminal 9 (Break-in) and 16
(GRND) with the Break-In switch ON.  I read about 500-600mA with a DMM
across 9-16 and the relay works without chatter.  However, looking at the
manual I see that the coils of the break-in relay K602 and the antenna relay
K101 are in parallel and are fed from the selenium bridge rectifier CR801.
I'm not 1200% certain but I believe the selenium was replaced about 10-12
years ago with a silicon bridge. 

 

>From the manual:  " The low-voltage secondary (terminals 8 and 10) of T801
supplies 25.2 volts ac to all filament, dial lamps, and oven-heater
circuits. A tap (terminal 9) on this winding provides 12 volts for dry-disk
rectifier CR801, to supply 6 volts dc to antenna relay K101 and break-in
relay K602."

 

However, with Break-In switch turned ON but rear terminal 9 and 16 NOT
shorted, I read 12VAC not DC across 9 and 16 on my DMM.   The break-in relay
is working and I don't think it would work well if it was a DC coil.  I hate
the thought of pulling the receiver out again but I am more concerned about
damaging the relays coils.

 

Any advice appreciated.

 

Happy Thanksgiving to All,

 

Jerry NY2KW