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Re: [TowerTalk] WTB: GAP VOYAGER and a Zero Five

To: towertalk@contesting.com
Subject: Re: [TowerTalk] WTB: GAP VOYAGER and a Zero Five
From: K4SAV <RadioIR@charter.net>
Date: Fri, 09 May 2008 17:57:17 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Here is an EZNEC simulation of the gain of a Zero Five using 32, 100 ft 
radials, average ground, and 100 ft of RG213, also including a 4 to 1 
balun at the feedpoint as recommended by Zero Five and assuming no balun 
loss.  The gain numbers are all at 15 degrees elevation, regardless of 
what the take-off angle is.  The last number is the amount of power 
dissipated in the coax assuming an input of 1500 watts.

1.8 MHz   -17.5 dBi,  1292 watts
3.5 MHz    -8.1 dBi,    598 watts
7 MHz       -3 dBi,    226 watts
10.1 MHz  -1.7 dBi,   532 watts
14 MHz     -3.3 dBi,   585 watts
18.1 MHz  -4.3 dBi,   306 watts
21 MHz     -3.1 dBi,   448 watts
24.9 MHz  -6.9 dBi,   674 watts
28 MHz     -12.2 dBi,  362 watts

Here are the gain numbers for the same set-up except no 4 to 1 balun:
1.8 MHz   -22.2 dBi
3.5 MHz    -10 dBi
7 MHz       -3.6 dBi
10.1 MHz  -4.8 dBi
14 MHz     -5.5 dBI
18.1 MHz  -5.2 dBi
21 MHz     -5.6 dBi
24.9 MHz  -9.6 dBi
28 MHz     -12.4 dBi

This is really comparing apples and oranges, but just for reference, 
here is the gain of a half wave dipole (one on each band) at 43 feet 
using 100 ft of RG213.  The gain is at 15 degrees elevation regardless 
of what the take-off angle is, and the gain is broadside to the dipole.

1.8 MHz   -5.9 dBi
3.5 MHz    -3.2 dBi
7 MHz       0.15 dBi
10.1 MHz   3.3 dBi
14 MHz     5.9 dBI
18.1 MHz   6 dBi
21 MHz      6.3 dBi
24.9 MHz   6.6 dBi
28 MHz      5.6 dBi

Jerry, K4SAV


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