[Hallicrafters] Which cap to replace molded paper

[Al Parker]

Hi Bill,
    I'm opening it up for criticism, but:
for almost anything except mica frequency determining caps, and
electrolytics, you can use plain jane, cheap, disc ceramics, (35-50 cts
each, or less).  Most are gonna be bypass caps, you don't need to spend a
buck apiece on them.  Sure, Orange Drops are the buzzword, and they're
good, but you don't need them, and sometimes they're just to bloody
awkward.  Actual value tolerance doesn't make any difference in such
applications.  +- 10% is plenty close enough.  When Hammarlund decided
BBOD's weren't any good, they used all disc ceramics in the SP-600's in
place of them (some were even coupling caps in the RF deck), and where
they had originally had specified .01 & .022 in various places, they noted
on the schematics to replace all with .01 when/if needed.
    We sure do get lathered up about this subject every so often, don't
we?  (I know there's always somebody coming along that hasn't been into it
b4, you're OK Bill)
73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.thecompendium.net/radio/
http://www.hammarlund.info



----- Original Message ----- 
From: "Bill Barfield" <barfworks at bellsouth.net>
To: "Hallicrafters List" <hallicrafters at mailman.qth.net>
Sent: Sunday, October 16, 2005 8:37 PM
Subject: [Hallicrafters] Which cap to replace molded paper


I appreciate the guidance all have given me as I step into the world of
boatanchor restoration. I thought I'd share a short study that I just
made.

I need to replace my molded paper caps and am bewildered by the choices. I
decided to do a type-by-type comparison to help highlight the differences
between n caps and their relative costs. All the replacements need to be
600v or above (some 630v).   As an example to compare, I will compare
.1mfd caps.

I have the following choices from Antique Electroinic Supply
(www.tubesandmore.com)  :

Mallory        Tubular metalized polyester            10%    Axial Self
healing    $1.05
Orange Drop 715p series    Polypropylene film    5%
$1.22
                    716p series    polypropylene film and foil 10%
$1.84
                    PS series    polyester film            10%
$1.42
Lolen Fast Metalized Polypropylene              tolerance not given
$1.85
(no name) Metal film Tubular    Non-inductive self healing windings
10%    $0.66

It looks like a choice between the Mallory and the no-name metalized
film/polyester caps. they are both self healing (does that help?)  I guess
the next question is whether the name brand "Mallory" is worth 39 cents.
Or, if I go with Orange Drop 715p, is 5% better tolerance woth another
17cents.

What do you guys use? Keep in mind this is to replace molded paper,
nothing more exotic.

Thanks,
Bill Barfield
KD4AL