I've been using RG142 with double silver plated braid for chokes. It
does have the advantage of 0.195" od and one time very small bend
radius. Rated 3.5kw and 1900 volts at 50MHz by Beldon, works fine here
at QRO.
Mine is real mil C-17 Thermax surplus, I got a 1200' spool in an
auction cheap.
Grant KZ1W
On 11/4/2014 11:19 PM, Jim Thomson wrote:
Date: Tue, 4 Nov 2014 13:43:57 -0600
From: "john@kk9a.com" <john@kk9a.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Terminate braid at top of tower...or
There is no RG-393 inside my Array Solutions or Cal-Av Baluns. Perhaps
you are using 10,000+ watt versions?
John KK9A
## I have 393 in both the array solutions w1jr boxes and also the cal-av
EB-3 bead baluns. Array solutions rates their box at 10-20 kw.... which I find
hard to believe..esp with just 4 x 2.4 inch od , type 31 cores used. balun is
rated for
160-10m. The cal av balun is rated for 10 kw... and down to 8.5 kw on 10
+12m...
and 5 kw on 6m. The cal av balun will take it easily.
## for the small amount of coax used in either style balun, I figured 393 was
a better bet.
It only has a 13 ga stranded, silver plated center conductor. It will hit
200deg C
when maxed out. The smaller rg-400 /303 coax only has a 18 ga center
conductor.
It too, runs hot when maxed out. They both need to be silver soldered.
## last thing anybody wants is a blown balun..esp when way out on a boom. I
have seen
several pix of folks removing huge arrays with a crane... then replacing the
blown balun with
an identical one ! They will get a repeat performance....and do it all over
again. The hassle
and expense of taking down a yagi is a pita..and huge $$ if a crane used.
The slightly added cost of building the balun stronger is well worth it. If
it wont handle at least
2.5 kw RTTY CCS 24/7 with 3:1 swr.... and some added inbalance, don’t
install it.
Jim VE7RF
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