[Milsurplus] RAK-7 caps - Bill's latest radio adventure

[Kenneth G. Gordon]

On 24 Aug 2015 at 10:15, Richard wrote:

> I have two RAL's and an RAK, and the biggest problem was badly aged 
> resistors, up to 11 times rated resistance to even non-conducting. 
> Fortunately they are mostly easily accessible.  The oil and paper 
> condensers are "probably" OK.  (I haven't needed to replace any yet.)  
> If used as a grid coupling capacitor I would replace it, otherwise go 
> slow.  Hint: Check the resistors first...
> 
> Richard, AA1P

In my experience with both the RAL and the RAK, the only caps which 
routinely give trouble are the mica coupling caps between stages. When you 
hear "static" even with no antenna connected, you will know that is what is 
happening.

The large, up-right mounted oil-and-paper caps have seldom been a 
problem...unless the receiver was stored for some time upside down and all 
the oil leaked out of them. (Ask me how I know this.) :-(

And, yes, the resistors are a BIG problem by now.

But, when the RAL or RAK are operating up to snuff, as far as I am 
concerned, they are the finest TRF receivers ever built....but I haven't yet 
used every one ever designed either.

Ken W7EKB