[Hammarlund] Hammarlund Digest, Vol 189, Issue 9

[Richard Knoppow]

    In the ones with paper caps one must replace ever single one of 
them. Some are hidden in the IF cans and elsewhere. Mostly not hard to 
do. The elecrolytics probably outlasted the bumble-bee caps but should 
be replaced anyway. I think Sprague had some sort of manufacturing 
problem. The caps used in the SP-600 were supposed to be deluxe quality 
but have to be shotgunned. The military rebuild used ceramic caps. They 
are much longer lived but modern plastic film caps are better. I don't 
think there is any reason to shotgun the ceramic caps but some do go bad.
    Some SP-600's had other brands of caps, white with stripes, but all 
are very old now so should be replaced.
    FWIW, the official name for the Sprague caps was Black Beauty, sold 
for high stress, high temperature use. Not all disintigrated, lots of 
them in old -hp- gear that are just old but not defective as are thoee 
Hammarlund got.


On 11/22/2023 6:38 PM, wes Bolin wrote:
> I still use my SP600JX21 that I restored in 2013.....it was made in 1953,
> 60 years earlier.   Works like a charm.  Replaced well over 60 capacitors,
> bathtubs, bumblebees, and electrolytics.  It is a super radio LOL.
> Wes


-- 
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998