[R-390] Audio components replacement.

[Tisha Hayes]

Quote:
On 1/3/2012 7:26 PM, Dave Mayfield W9WRL wrote:
Does any one sell a rebuild kit for the R-390a audio deck, also I think
some recommend replacing some of the resistors. I know I can buy them
from Mouser but would a lot faster to just  buy a kit from someone,
assuming the price is not in in the F layer or higher.
End Quote:

There are also some capacitor modifications that can improve the low
frequency response of the audio deck. You will want to get rid of the
8 uFd "acid capacitor of death" that is in the middle of that strip
under the audio deck. Chuck Rippel, WA4HHG had a pretty comprehensive
list of components to replace that make a real difference to the sound
of the receiver. That can be found in the Y2K documents under the
supplements section where most of the mods are incorporated into one
chapter.

At one time Chuck would sell a little kit of capacitors for the mod. I
do not know if he still does that as I think he has taken a less
active role in restorations as it was becoming more of a full time
job.

I would not go so drastic as the Felton mods where there is major
rewiring and tube change-outs. I have modded one RF deck to add the
squelch facility (really tough to find that 10 Kohm relay) where the
blanker plate is located on the audio deck (near where the modular
plug is). That takes a an additional tube socket (6C4) a relay and a
handful of other components with a slight mod to the power rotary
switch to allow you to rotate to the hidden squelch setting on the
knob.

I have looked over the resistor component values in the audio deck and
while there could be some optimization of values it just did not seem
to be worth that much effort. Actually running the audio off of the
diode screw terminals into a high quality equalizer and amp gave the
best results so far.

-- 
Ms. Tisha Hayes/ AA4HA
-
“But what is liberty without wisdom, and without virtue? It is the
greatest of all possible evils; for it is folly, vice, and madness,
without tuition or restraint.”   Edmund Burke