[Boatanchors] NC-188 re-cap query

[Troglodite@aol.com]

In a message dated 1/9/03 2:39:19 PM Central Standard Time, 
googlyelmo@earthlink.net writes:

> I am recapping my newly acquired NC-188, as hopefully the remedy to getting
>  nothing but very loud buzz out of it at the moment.

The buzz is probably bad electrolytics. You might consider replacing these 
first, and possibly be encouraged by hearing some signals. Not that you 
shouldn't replace the paper caps anyway, but starting with some sound will 
let you judge the improvement along the way and check for possible errors.
  
>  There are several caps that resemble dominoes, little red-brown dominoes 
with
>  six variously color spots on them, and I don't know how to read their color
>  code, or what type of cap they are, and thus if I need to replace them only
>  with a modern equivalent(?) Please tell me if you can how to read and treat
>  these.

These are mica capacitors and generally don't go bad, though it has been 
known to happen. For instructions on how to read them, and a pretty good 
treatise on recapping in general, check out Phil Nelson's site at 
http://www.antiqueradio.org

>  Also, this being the first time I have completely recapped a receiver, 
should
>  I replace all the disc ceramics with film/Orange Drop type caps, or just 
plain
>  discs?

Again, the discs generally don't go bad, but there's always the exception. 
The wax/paper caps have a built in failure mechanism (moisture penetration) 
and will time out eventually, which is why most people do a bulk replacement 
of them. The same holds true for electrolytics, though some will last a 
surprisingly long time. The rest of the caps are usually replaced on an "as 
needed" basis.

Old wax caps that have been leaking for a long time may also cause associated 
resistors to drift in value. (Resistors can also drift on their own for their 
own reasons.) Generally, if it's worth recapping the set in the first place, 
it's worth taking the time to do it right. Everybody has their own approach 
and philosophy on this.

Have fun, be careful, and take notes.

Doug Moore KB9TMY