[TowerTalk] 160m project

[Jim Brown]

On Sat, 10 Jan 2009 22:40:58 -0600, Its from Onion wrote:

>260 feet of #12 wire suspended at or about 85 feet.

That's fine for 160, but to work most of the other bands, consider 
the HyPower loaded 160/80 dipole, then add a parallel 40M element to 
it. Feed it with RG8 or RG11 and one of the coaxial common mode 
chokes described in 

http://audiosystemsgroup.com/RFI-Ham.pdf  

For details of the parallel fan, see

http://audiosystemsgroup.com/LimitedSpaceAntennas.pdf and 
http://audiosystemsgroup.com/LimitedSpaceAntennasPPT.pdf

Google on HyPower Antenna Company to find them. 

This antenna will work VERY well on 160, 80, 40, 30, 17, 15, and 12M, 
and will be MUCH quieter than the one you've described. I've even 
loaded it on 6M and made a bunch of 2,500 mile contacts with 100 
watts! Mine is up 100 ft -- it should also work VERY well at 85 ft. 

>65 feet of 600 ohm ladder line feeding the wire directly.
>A mil-spec balun from Antenna Products rated at 2-30M 4Kw PEP
>http://www.antennaproducts.com/BINDEX.htm<about:blank> SM-153.
>50 feet of 9931 coax with a 6" PVC air choke made from 25 feet of 
9931 wrapped. 

This is NOT a very effective feedline choke. You'll pick up a lot of 
RX noise with it. Don't waste your money on any commercially made 
balun or common mode choke. The ones you can wind yourself on five 
toroids are FAR superior. The problem with twinlead is that you can't 
put a good coax choke at the feedpoint, so the antenna picks up noise 
from the feedline. 

If you're able to use a manual tuner, find a Ten Tec 229 or 238 used 
(about $250-$275 for the 229, $300-$350 for the 238).  

>Legal limit when needed from a AL-1200 Ameritron.

The antenna I've described can be built in a day, and you can build 
three in only a bit more time. So your friends who are helping you 
with this antenna can build one for themselves while they're building 
yours!  You're also going to want to put together a group purchase 
for some ferrite cores. See detailed advice on that in Appendix One 
of the RFI-Ham piece. 

73,

Jim K9YC