[TowerTalk] 402CD - Does it need a balun?

Dave Hawes n3rd@ix.netcom.com
Tue, 3 Feb 1998 03:37:14 -0400


Didn't see my post reflected back to me, so I'll try it again.

------- Forwarded Message Follows -------

Today, I took advantage of the unseasonably warm weather we're having
here in the Philadelphia area, and took down my 402CD.  Something
electrical had gone wrong, and I suspected that a loading coil had
opened up.  I was prepared to do the QHS machine screw replacement
routine for the sheet metal screws, although before putting it up, I
had replaced the plated screws with stainless.

Well, it wasn't the loading coils, but the balun, a W2DU current
balun.  It was reading a very high NEGATIVE resistance on my Fluke 77
(can anybody tell me why it was NEGATIVE?), so I figured it was
history, and took a hacksaw to it.  When I cut the top off, a whole
lot of BROWN WATER came out.  Upon inspection, I could find absolutely
no way for water to get either in or out of the balun, save for the
center pin on the UHF connector.  The failure was the wire had
corroded and was nearly broken off on the center conductor connection
to the solder lug on the inside of the balun tube.

So, can anybody recommend a good current balun to use with the 402CD,
or is one even needed?  Why can't I just follow the directions in the
manual and make a coil of coax?

I have NEVER used a balun of any type here before this W2DU, and I'm
batting 0 for 1.  Advice appreciated.  I'd like to put the thing back
up next weekend.

Thanks for any help.

73 - Dave N3RD
n3rd@ix.netcom.com
http://www.QTH.com/topten

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