[Boatanchors] NC-188 re-cap query

Thu, 9 Jan 2003 17:36:56 -0500

----- Original Message -----
From: "Will" <[email protected]>
To: <[email protected]>
Sent: Thursday, January 09, 2003 3:35 PM
Subject: [Boatanchors] NC-188 re-cap query

> 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.

Leave the radio off until you replace the PS electrolytics. I believe the
audio cathode bypass cap is in the can also.
In any event you dont want to fry the xfmr.

>
> 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.

Those were generally OK if they are about half the size of a postage stamp.
The larger ones may suffer from the same problems as paper, the bakelite
seal is less than perfect and moisture gets inside. If the case is bulged or
cracked along the seam, replace it.
National used several suppliers, different run of the same model could have
different caps. Its been a long time since Ive been in a 188.

>
> 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?

Leave the discs alone, unless they are physically damaged they are reliable.
Start with the electrolytics and then turn it on. Since this is your first
attempt do only one or two of the paper caps at a time. Turn on the radio to
at least make sure it didnt get worse.
If you have a camera, EMail me an underneath shot, I can ID the trouble
brands.

Carl  KM1H
National Radio 1963-69
Service Tech, Service Mgr, Engr Aide

>
> Thanks.
>
> Will, KD7BFX
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