Well my 70' Rohn 45 in the air. As is the Orion OR-2800 rotator, (the mounting
of this rotor is the coolest thing since sliced bread!!!) 21 foot galvanized HD
steel mast, (not water pipe), a 2 element Cushcraft
40 meter beam (Older one) and a TH7 that I just went through and replaced
hardware and the matching section is all new.
Just after the 40 was put up, I checked the match with my MFJ-259B. It was
resonant at 7.080.
Now the TH7 just went up 9' below the 40. Re-checked the match on the 40 and it
was not resonant at 7.090. Looks as if the 2 element is effected little by the
tribander.
Now checked the match on the TH7, I was not so good.
The TH7 is using the "DX" element lengths.
20 Meters: flat at 14.090. Climbs to 1.3:1 at 14.000 and up to 2:1 at 14.250.
15 Meters: 1.2:1 at 21.390 Never lower than that.
10 Meters: 1.2:1 at 28.600. above 2.5:1 at 21.100.
This is measuring at the end of the jumper hooked onto the balun.
The booms of the 2 antennas are parallel.
Any input would be helpful!
Thanks and 73
Jim W7RY
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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