Exactly, there is no problem with overheating on a yagi.
I use 12 windings of RG141 on a 61 mix toroid on 40m and less on the higher
bands when not winding the feed line to a solenoid.
All mine are on fresh air without any box.
73
Peter
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Hans
Hammarquist via TowerTalk
Sent: Dienstag, 4. November 2014 19:01
To: towertalk@contesting.com
Subject: [TowerTalk] Fwd: Terminate braid at top of tower...or
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@kk9a.com>
To: towertalk <towertalk@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@telus.net>
Subject: Re: [TowerTalk] Terminate braid at top of tower...or
From: Stan Stockton <wa5rtg@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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