[TowerTalk] Fwd: Terminate braid at top of tower...or

[Hans Hammarquist via TowerTalk]

Remember that the heat generated is a function on how the load (the antenna) is balanced. On an OCF (Windom) you never know. Only the common mode current is generating power loss in a current choke. No CMC, not power loss.




Hans - N2JFS



-----Original Message-----
From: john <john at kk9a.com>
To: towertalk <towertalk at contesting.com>
Sent: Tue, Nov 4, 2014 8:38 am
Subject: Re: [TowerTalk] Terminate braid at top of tower...or


Array Solutions mounts their choke in a small plastic Nema junction box.
They use small Teflon coax and I believe it is around a single core in
some of their models. DX Engineering mounts their chokes in a small
aluminum enclosure.  Cal-Av mounts theirs in PVC tubing. Is heat a big
concern?

John KK9A


To:	Jim Thomson <jim.thom at telus.net>
Subject:	Re: [TowerTalk] Terminate braid at top of tower...or
From:	Stan Stockton <wa5rtg at gmail.com>
Date:	Tue, 4 Nov 2014 06:56:22 -0600

I also have trouble contemplating having a big wad of heavy cores hanging
from
the driven element of a large Yagi where the driven element may be 30 feet or
more from the mast.

Reading K9YC materials it appears that anything less than 5-9 cores just
wouldn't be good enough to do a good job on 14-30 MHz.

Look at the specs on the Balun Designs two core choke wound with RG-400,
rated
at 5KW and sealed in a plastic box.  Are those specs wrong or is there a
discernible difference between that one and one wound on more cores?  Will
that
choke, rated at 5 KW, handle 1500 watts in a contest?

One other thing that is difficult for me to understand...  Why would anyone
ever consider using RG-58 or relatively huge diameter, heavy RG-213
(requiring
more cores) as suggested in the material when silver plated,Teflon insulated,
higher power handling, stranded center conductor RG-400 is available for very
little money.

I am gathering the ingredients to make some chokes.  Do not want to be in
situation where what I don't know DOES hurt me.  Heretofore most of my
antennas
have had coax wound on a piece of PVC.


73...Stan, K5GO

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