[TowerTalk] 80M antenna wire size

[Jim Thomson]

Date: Sat, 4 Jan 2020 14:37:10 -0700
From: David Gilbert <xdavid at cis-broadband.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] 80M antenna wire size


<According to EZNEC+, an 80m dipole at 100 feet (resonant and matched at 
<3.7 MHz) has a 2:1 SWR bandwidth from 3.55 MHz to 3.87 MHz with #10 
<copper wire and from 3.57 MHz to 3.86 MHz with #18 copper wire. Much 
<thicker conductors or similar conductors at higher frequencies would 
<make more difference of course (I've modeled 12 inch diameter wire cages 
<for 80m and they make a usable improvement in bandwidth), but in spite 
<of what somebody just posted the advantage for #10 wire on 80m does not 
<seem significant to me for bandwidth.

<Dave?? AB7E

##  10  gauge  wire  is  .102  inches  in  diameter.
      18  gauge  wire  is .0403  inches  in  diameter.

##  .102 / .0403  =   2.531  

##  10  gauge is  2.531  x  the  circumference  of  18  gauge  wire.   Thats a bunch.
Thats a huge  difference  in  Length  to  diameter  ratio. 

##  I  have  never  tried a    80m  wire dipole  at  100  ft,  but  have
used  a  full  sized  wire  inverted  vee  on  80m. 

##   10  gauge  wire  provided  for a   much wider  BW,  vs  the   16  +18  gauge  I  tried  previously. 
2  other  folks here  in  town tried the  same experiment...with  same  results.   Again,  inverted  vee  used.
Is  EZNEC modeling    your  dipole  correctly ? 

Jim  VE7RF