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

[Jim Thomson]

Date: Tue, 4 Nov 2014 13:43:57 -0600
From: "john at kk9a.com" <john at kk9a.com>
To: towertalk at 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