Topband: 160M Balun

[Jim Thomson]

Date: Fri, 30 Mar 2018 07:22:18 -0400
From: "N2TK, Tony" <tony.kaz at verizon.net>
To: <topband at contesting.com>
Subject: Topband: 160M Balun

<I shunt feed my tower for Topband. Presently using a Comtek 100 bead balun.
<After reading K9YC's article on baluns it would seem that a stack of five
#31 cores with 7 turns of coax would be a better balun.
<Would I notice an improvement in any way by switching baluns? 
<If the answer is I would notice an improvement what about using sixteen
<turns #12 THHN wire on  #31 core as shown in K9YC's article? How many cores
<would I need for 1500W?
<Tnx for any feedback

<N2TK, Tony 

##  Although  7 turns   of  213  sized coax  through  5 x  type  31  cores  works good
on 160m...  aprx  5 k ohms,  the choke will resonate on 3 mhz !    You cant get more than
7 turns of coax through a 2.4 inch OD  /  1.4 inch ID  core.   The  160m CM choke needs 
to resonate lower in freq.  It requires  more cores to shift the res freq down.   I dont
know how many more,  but I suspect   7-12  cores  would do the job, and certainly
be an improvement.     You wont blow it up either.

##  I suspect your current  bead balun  wont provide very much Z  on 160m..and it
will all be reactive. 

Jim   VE7RF