Read the supporting study - the details of the test method are explained
pretty clearly. Then you can make your determination as to the validity of
the methods employeed.
73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie
-----Original Message-----
From: Bry Carling AF4K
Sent: Monday, April 13, 2015 11:12 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] [Bulk] Re: antenna choices for K4XS
Very good point. I do not know whether these deep scientific studies were
done at NEAR
FIELD to the antennas or at distances of hundreds of miles away.
The articles / books claim that these yagoi beams have virtually no gain at
all. I wonder
whhow NEC would stack up against their measurements? It's in a boob, or
article so it MUST
be true. I am just left pondering the same as you - trying to decide where
ALL that extra
power is disappearing to...
On 13 Apr 2015 at 7:40, Markku Oksanen wrote:
On "Low Performance Trap Antennas" : Is it really known what is the cause
for the apparently very large difference between a correctly designed trap
beam, say a TH6DXX or similar and one of the not so good performers? Trap
loss can't be a big part because even relatively low power loss at a given
trap, say 50 W, will burn the thing very quickly. Assume 3 elements, 6
traps that get exposed on a given band and -3dB gain compared to better
beam, this would be some 1500/2/6 watts, a lot of watts per trap. Even it
not this much just loss, there would be ample power to melt the insides of
the trap.
MarkkuOH2RA/WW1C
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