[R-390] 600 to 8 ohm speaker converter

[Steve Toth]

AND IIRC there is the junk box solution: if you really need a quick working low-buck fix and can't find the correct parts, you can use a 115v to 12.6v filament transformer to connect the 600ohm output impedance to the 8ohm speaker.
- Steve  W7SJT
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On Monday, February 14, 2022, 12:17:07 PM MST, Barry <n4buq at knology.net> wrote:

 If I remember correctly, a 70 volt line speaker transformer can be used and I think that's what you're showing on the left.  An 8-ohm speaker goes to the 8-ohm output lines and the line output goes to one of the wattage taps.  I can't see the labeling on the back side of the transformer in you picture so not sure which wires those are but typically there would be one common input with multiple taps for various wattage (or volts).  As I recall, there is a recommended tap to use but I think I tried a few of them to see which one gave the best output.

HTH,

Thanks,
Barry - N4BUQ

----- Original Message -----
> From: "K PERALES" <kenperales at comcast.net>
> To: "R-390 Mailing List" <R-390 at mailman.qth.net>
> Sent: Monday, February 14, 2022 12:49:17 PM
> Subject: [R-390] 600 to 8 ohm speaker converter

> When I got my R-390 it has what I assume to be some kind of transformers to
> allow a modern 8ohm speaker to be hooked up.  I did not think to diagram how
> the wires were hooked up.  Is there any manual that tells a non-electrician how
> to connect these transformers to the R-390A to let me listen without
> headphones.
> 
> Ken
> 
> 
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