[TowerTalk] EFHW core

[Jim Thomson]

Date: Tue, 29 Sep 2020 10:07:32 -0700
From: Jim Brown <jim at audiosystemsgroup.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] EFHW core

<If that's true, I'll bet it wasn't the result of an infinite number of 
<monkeys and typewriters, but the rather the result of serious 
<understanding of how antennas and networks work, combined with some time 
<in the lab optimizing!

<Don't know who Danny Horvat is, but the "Danny" that I exchanged round 
<robin testing with ten years ago is a pretty sharp cookie.

<73, Jim K9YC

##  Danny  Horvat is beyond a smart cookie.   How many  CM chokes do you see that cover  160-10m,
with 8-12 K of  RS..and  RS  >  XS  ?   No  Z  bumps  either.   Ingenious staggered core design.   And  no,
you wont blow em up with  4 kw.

##  His latest version starts at 7.3 k....then  increases  to  10k on  80m....and keeps going up, up, up to 15.2 k on 10M. 
Typ, the noise level will  drop between  1-4  S units, depending on band. 

##  he has another version that is 7.4 K...on  6 M  band.   3 kw on  6M. 

##  His EFHW  ants  all work well, and low swr for the most part.

##  Not  every new unique design, or  concept, is in the  latest  ARRL  ant  book either.

##  Danny  pointed out to me some teflon coax,  thats  bigger  than  RG-400, but  smaller then  RG-393. 
It can be wound fairly tight onto 2.4 inch OD,  type  31 cores.  He custom made a 80m  CM balun out of this
in between coax..and sent it to me to experiment with.   Works superb, currently being used on a buddys
75m ant,  with  +  69 dbm. 

Jim   VE7RF