[R-390] Selenium rectifiers

[Paul H. Anderson]

On Thu, 21 Jun 2007, Don Reaves wrote:

> I asked this question because I have one of the R-391 matching 28V power
> supplies, PP-629.  It has a beautiful selenium rectifier stack in it about
> the size of a loaf of bread.  I'm going to leave it alone and use it as is.
> It's job is to run the autotune circuits in the R-391.

I think the R-389 has a smaller version (one in between the PP-629 and the 
antenna relay rectifiers on R-390, R-390A and R-391's).

I imagine the need to replace it depends on how close to design limits it 
normally operates at, and how that interacts with the normal failure 
modes.

Paul