Hi,
I too had a TH3, but based on models and Steve's talk at Dayton went to a 2
el, but in a somewhat different manner. I considered the C3S but cost drove
me to a semi homebrew solution.
I reasoned that the problem with trap beams was the narrow bandwidth of the
parasitic els (Steve's figures showed about similiar max gains available
from trapped beams but over a narrower BW), so I used monoband reflectors
(used Hygain's dimensions from their monoband beams) with the TH3 driven el.
I used a TH2 matching section. I spaced all the reflectors .15 wavelgts
from the DE (appeared to be about max for a 2 el using MNjr and YagiMax).
Results for DX and contests are better than the TH3 so I guess gain is as
would be expected. SWR readings (measured through 90 feet of RG8 foam and
MFJ259B) are:
14.00 1.8
14.12 1.1
14.29 2.0
21.00 1.9
21.19 1.0
21.42 2.0
28.0 1.4
28.3 1.0
28.9 2.0
Nice thing is low wgt (I calculate abt 25 lbs), no tuner required for 99% of
my operating, and cost was about $25 (I buy any used Hygain beams I come
across).
73, Ed
Ed Jensen, K5ED, El Paso, TX, k5ed@dzn.com
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