Hello all,
Next project is to increase the antenna spacing on the crank up tower's
mast. Currently a TH11 is 6" above the tower top and a 402BA old HyGain 40
meter monobander is about 10' above it. Currently, there is some slight
degradation on the TH11's 15 and 17 meter bands resulting in a slightly high
(3.0 on 17 and 2.2 on 15...not too bad) VSWR.
The new antenna project calls for a Force 12 EF-30/40 to replace the HyGain
402BA. However, after discussions with Force 12 and this reflector, most
think that 12' spacing would lessen interaction between the antennas. So the
question is, without purchasing a new mast, how does one elongate the
current one? I have considered both internal and external sleeving methods
measuring about 3' for an 18" overlap. To accomplish the extra 2 to 3' in
mast length, the extension would be the same size as the current one. The
internal sleeving method appeals most since the antenna can be placed on the
mast at a lower level then slid up the mast into the 12' position. The
current mast is 2" OD and .250" wall thickness. Any one tried this approach?
Thanks,
Bob, K3GT
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