[R-390] My 'new' R390

[Jordan Arndt]

First things first, to me at least:

Make sure you have a proper impedance matching transformer connected across 
the Local audio output on the rear panel and feeding an 8 ohm speaker. 
Relying on an external device like your Kiwa MAP can mask problems with the 
radio.

I've had some success getting the power micro-switch to work by repeatedly 
switching between OFF and Standby with a mild amount of force. I've also 
seen micro-switches that are only very slightly mis-aligned which can be 
adjusted to the correct position.

If you look closely at the micro-swtich assembly, you'll see that it is 
activated by a cam which presses on or releases the contact lever to open 
and close the circuit. You might be able to get some cleaner/lubricant into 
the small lever opening. It's entirely possible that it's stuck "on" with 
dust, dirt and other gunk.

Going further with work on the switch will require pulling the front panel 
IIRC...

Congrats and good luck going forward with your R-390....!!

73...Jordan VE6ZT

----- Original Message ----- 
From: "Adam Morehouse" <morehouse90 at gmail.com>
To: "R-390 Mailing List" <r-390 at mailman.qth.net>
Sent: Thursday, August 14, 2025 6:25 PM
Subject: [R-390] My 'new' R390


>I brought up my recently acquired R-390 slowly on a variac. No smoke, and
> it picks up stations - not quite as good as my R390A, but thats to be
> expected since its been asleep for 20 years.
>
> Power switch doesn't turn off, I'll need to find one. Local Audio is
> extremely quiet unless the BFO is turned on, then it's too loud (turned 
> all
> the way down and it's still booming). Line meter also doesn't function
> unless the BFO is turned on. With my Kiwa MAP hooked to IF out, it sounds
> decent.
>
> Where should I start :D
>
> Adam K2AAM
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