Hi Jim -
I've had the same problem with two YA-1's. If you drill out the rivets you
will find, as one would expect, a multi-pole low-pass filter comprised of
multiple L's & C's. The L's are straight forward and are made from heavy
solid wire (I'm guessing #10). The problem occurs with the C's. The caps
are made from two conductive end plates separated by different thicknesses
of mylar and teflon disks as the dielectric. The C value is determined by
the thickness & make-up of the dielectric disks. What happens is there is
breakdown of the dielectric at high power levels . When you open the filter
you will see (the carbon flash over spots are easily visible) which caps
arc'ed. The ones that fail, at least in my experience, are those going to
ground; they have the highest potential difference applied. The capacitors
are held together by screws, washers & nuts. There is a slight change in
capacitance as a function of the torque applied, but it is a small change.
Note also that the rivets (that you drill out) can be easily replaced with
pop rivets or you can use sheet metal screws.
I have found that the YA-1 can't be beat for the money!
(See my direct mail for additional info regarding solution to your problem)
----- Original Message -----
From: "WW3S" <ww3s@zoominternet.net>
To: <towertalk@contesting.com>
Sent: Sunday, November 16, 2008 2:47 PM
Subject: [TowerTalk] what can go wrong with a Bencher YA-1 low pass filter
> In the middle of SS this afternoon, started to get very high swr on
> transmit, although receive signals seemed fine, after trying different
> jumpers, etc, isolated it to the Bencher low pass filter....unit is
> riveted,
> are there any servicable parts inside? What can go wrong?
>
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