Rule #1 of minimizing maintenance: Don't put moving parts somewhere
where they are hard to get to for repair/replacement.
Barry W2UP
On 8/7/2017 11:59 AM, Jim Brown wrote:
If you don't need to tri-plex it to two radios, it's hard to beat a
SteppIR. My neighbor K6XX has wrangled my straight 3-el at the top of
my 120 ft tower without difficulty. Standard procedure is to assemble
and test it on the ground, then remove the elements, pull both
elements and boom up the tower, and reassemble. That straight 3-el is
light enough for one strong guy to handle pretty easily, and it's gain
is comparable to any high-efficiency 3-el Yagi (meaning full-size
elements, without traps). If you doubt that, I suggest that you read
N6BT's self-published "Array of Light" book, wherein he debunks some
of the phony claims and "physics from another universe" used in
advertising for some of these products. Some of these ads, for
example, claimed greater gain than an ideal monoband Yagi with the
same number of elements and boom length.
If you do need to tri-plex, I'd look at the new products from G0KSC.
73, Jim K9YC
On 8/6/2017 2:48 PM, K9MA wrote:
My 28 year old TH7 needs to come down for maintenance, and I'm told
the trap end caps MFJ now sells don't last long. I also may be just
a matter of luck that no bugs have moved into any of the traps. So,
I'd really like to replace it with a trapless antenna. The TH7 has
served me well, having last been put up in 1993. It needs to be
replaced before I'm too old to climb the tower!
Here are the requirements:
Performance comparable to TH7
Boom length 24 feet or less
No traps or fragile linear loading
Can be assembled on the tower (as was the TH7 in 1993.)
At this point, the Skyhawk appears to be my best option, at least of
the tribanders available in this country. Any experience with the
Skyhawk, or other suggestions?
73,
Scott K9MA
----------
Scott Ellington
--- via iPad
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