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

[Barry Scott]

Since there's no filtering, you're reading the full ripple voltage.

Thanks,
Barry - N4BUQ

On Wed, Nov 27, 2024 at 7:46 PM <k1jos at att.net> wrote:
>
> 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
>
>
>
>
>
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html