[Milsurplus] Navy RAK Caps

[Kenneth G. Gordon]

On 28 Feb 2018 at 1:54, Joe Connor via Milsurplus wrote:

>     I'm working on a Navy RAK receiver and need some guidance. It's my first 
> regen and I'm having a ball playing with it. 

The RAK is a pretty snazzy receiver.
 
>     1. There are several .01 caps that are in brown plastic cases. The manual lists 
> them as mica. Are they? That seems an awfully large value for a mica cap.

Hmm....I would have trouble believing a mica would be that high in capacitance too, but 
maybe. In any case, there are interstage coupling capacitors that, what ever value they are 
(I'd have to go look that up) they DO get leaky. The way you can tell this easily is to remove 
the antenna, set the receiver up for max sensitivity, then listen for low level static noises. If 
you hear static with no antenna connected, suspect those interstage coupling caps first.

>     2. This receiver has a large number of oil-filled caps in metal cases. The 
> prevailing wisdom is that oil-filled caps are usually good to this day. In this 
> receiver, two of them (both 1.0 mfd) had obvious oil leakage, so I replaced them 
> Does the fact that two of them were bad suggest that others in this set are 
> probably bad, too? None has any obvious oil leakage.

Most likely not. However, you may wish to at least check a few of them.

I have one RAK-8, brand-new, which was stored upside down and every oil-filled cap in that 
receiver lost all its oil. What a terrible mess! 

Ken W7EKB

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