[TowerTalk] Tribander losses

[i4jmy@iol.it]

It depends by which F/B, BW, and feed point numbers are considered the 
good ones. (it's a very individual point)
Assuming to be slightly pessimists, fixing a F/B that's 20/25 dB along 
the band (30/35 dB at best spot), desirying a full band coverage (Gain, 
F/B and SWR) and acepting 20 Ohm as the minimal feed point resistance, 
on a 24 ft long boom we can built:

1) 3 elements on 14 MHz and 8.3 dBi gain
2) 4 elements on 21 MHz and 8.8 dBi gain
3) 5 elements on 28 MHz and 10.2 dBi gain

Some higher gain (< 1 dB) is possible at a significative F/B and BW 
detriment.
Higher gains at very low feed point resistances are a mith.
That sort of gain stay on the paper because is always vanished in the 
matching unit.


73,
Mauri I4JMY



> ---------- Initial message -----------
> 
> From    : owner-towertalk@contesting.com
> To      : towertalk@contesting.com
> Cc      : 
> Date    : Tue, 18 Jul 2000 01:07:19 +0000
> Subject : [TowerTalk] Tribander losses
> 
> 
> Can anyone advise what gain should be expected from 3 monoband 
elements on
> a 24-foot boom on 20 and 15, or 4 elements on 10 (assuming reasonable 
SWR
> bandwidth and F/B performance across the band)?  
> 
> 73, Pete Smith N4ZR
> 
> The World Contest Station Database 
> is back up and running at
> http://www.qsl.net/n4zr 
> 




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