I have a 97-foot Rohn 25 tower with 2 X C-3Es and an EF-240S on top. I
tried initially to find a 50-ohm point on the tower, without success, so
I then went to an Omega match, using a pair of 300 pF transmitting
variable capacitors bought from Henry Radio. It proved very easy to
tune, with reasonable bandwidth, and works fairly well despite low power
an an inadequate radial system.
You might be able to switch in another match for 80M, but instead I use
a 4X lazy vee array - See K3LR's article in QST August 1994 - hung off
the same tower. It has definite though broad directivity and is just a
few Db down into Europe, compared to an 80M 4-square. If anything, I
believe the tower helps the directivity.
73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.
On 8/25/2013 11:43 PM, Jeff Blaine wrote:
A buddy of mine has a 100’ 25G tower and wants to run it on both 160/80. I’m
thinking a par of shunts will work for that?
If you have done this, I would be interested in your comments on the general
implementation.
Thanks!
73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie
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