[Boatanchors] Disc caps vs paper caps

[james.liles at comcast.net]

Hi Joe:

A good solution is to use a 1600 volt Polypropylene capacitor.  the 
characteristics of the Polypropylene cap are similar to the class 1 
Ceramics.  Capacity does not vary with voltage, no hysteresis effects, very 
low dielectric absorption at high frequency, temperature stable, no micro 
phonics, work well to 200Mc and above, and don’t age like the class 2 and 3 
high K Ceramics.  Real safe bet.  Used in motor start/run caps as well. 
Careful if you call them orange dip caps --- it's like a telling your wife 
that she is ugly.  All this can be substantiated in any research paper and 
you can verify with simple tests in your shack.

BTW, short tale.  Im an old timer who flew behind a prop whos tips were 
close to the sound barrier.  Hearing is el stinko.  Had rabbits in the 
garden and decided to discourage them with a sonic device.  Plugged it in 
outside and checked that the dogs could not hear it.  They didn’t!  Walked 
into the house and my wife commented that there is a raspy sound like a 
squirrel choking on an acorn.  I asked her where had she ever seen a 
squirrel choking on an acorn???  I envisioned a squirrel laying upside down 
trying to get someone to do the Heimlich process.  Couldn’t think of any way 
except to step on it because he wouldn’t turn over ---- decided the squirrel 
could not be saved.  Came to my senses and stepped outside and unplugged the 
sonic device, returned and asked my better half, is it gone?  Answer -----  
Yes what did you find?  I said a squirrel choking on and acorn!  She said 
she was right after all, is he ok now?  I said yes and let the rabbits have 
their way.

Kindest regards Jim K9AXN


-----------------------  ORIGINAL 
MESSAGE --------------------------------------------

Message: 8
Date: Wed, 26 Sep 2012 20:32:53 -0500
From: "Joe Walden" <w5jdy at cox.net>
Subject: [Boatanchors] Disc caps vs paper caps
To: <Boatanchors at mailman.qth.net>
Message-ID: <000001cd9c50$04042670$0c0c7350$@cox.net>
Content-Type: text/plain; charset="us-ascii"

>From Joe w5jdy in Norman,Ok..  I am restoring a Zenith 1930's 6vdc farm
radio that uses a synchronous 6 pin vibrator in the power supply (no
rectifier tube)..  In the schematic it shows .01 paper caps at 1200volts
from each side of the vibrator transformer secondary to ground..  Is it OK
to use disc ceramics in their place..  I have some at 3 kv..  I think
Sprague makes a  .01 at 1600 volts but I am having trouble finding them??
Thanks all..  Joe