[R-390] R-390 mods and weak points

[David C. Hallam]

The 47 ohm resistors apply to the R-390.  They are 2W carbon comp 
cathode resistors in the power supply and over heat badly.  Change them 
to 5W ceramic composition resistors.  Be sure and add the cooling fan to 
direct air on these resistors.  That area gets hot. The series B+ 
voltage regulator generates a lot of heat.

There are no "death caps" in the r-390.


David
KW4DH

On 12/6/2012 3:13 PM, Robert Newberry wrote:
> I've been reading various websites and archived threads. I have a non A
> R-390 that is all torn down to individual modules. My questions are.
>
> Is there any caps or resistors that should be checked or replaced? I've
> read alot about "death caps" and 47 ohm resistors but everyone was talking
> about R-390A.
>
> Are there any recommended mods? For example I've read about fatting up caps
> in the audio module to get more low end audio. Although these were
> referenced to the R-390A. I'm all set with the inrush mod for slower start
> up and hanging a fan to aid with cooling.
>
> Thank you
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