[TowerTalk] New Tower up With Some Issues 2L40 TH7

Jim W7RY w7ry at centurytel.net
Sat Feb 14 17:27:13 EST 2004


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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