[TowerTalk] [Bulk] Re: antenna choices for K4XS

[Peter Voelpel]

Where is that supporting study?

I doubt that they measured within the main lobe of the antennas on the
comparison test. 

73
Peter

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Jeff
AC0C
Sent: Montag, 13. April 2015 18:15
To: bcarling at cfl.rr.com; towertalk at contesting.com
Subject: Re: [TowerTalk] [Bulk] Re: antenna choices for K4XS

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 at 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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