[R-390] Ebay Auction

[Roy Morgan]

At 10:04 AM 11/17/2007, ToddRoberts2001 at aol.com wrote:
>
>I can see 2 things wrong with the picture. The R-389 on the bottom does not
>have the original tuning knob.

R-389 trivia lovers,

The R-389 has a unique knob. The knob has a friction clutch inside it.  If 
that clutch is frozen up and a hammer-fisted person forces the shaft beyond 
it's stop, it can do serious damage to the PTO.

I suspect also that in a properly working radio, if the knob is held still 
and the motorized tuning is engaged, the motor will slip the clutch.

>  Also mounting an R-389 directly below the R-390A
>is going to cook both receivers.

Indeed.  The R-389 has the same power supply with series regulator tubes as 
found in the R-390/URR and R-391.  It appears from the auction description 
that the case being offered is quite well sealed up.  Based on my 
experience with the R-390/URR and a fan, I believe that a modest amount of 
cooling air does wonders.  But it would have to circulate in and out of the 
case.  That fiberglass case may be adaptable to install dependable air 
movement. It's hard to tell.

May your radios run cool and long.

Roy



- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing
13033 Downey Mill Road, Lovettsville, VA 20180
Phone 540-822-5911   Cell 301-928-7794
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