TopBand: EWEs

[Tom Rauch]

> Date:          Thu, 02 Apr 1998 22:06:41 -0500 (EST)

Hi Earl,

The EWE is easily and correctly analyzed as two short verticals.

> 33.5 degrees.  The 180-S formula says that, for max F/B, that phase
> difference should be 180 - 33.5 = 146.5 degrees (or inverted, -33.5
> degrees?).  Nothing seems to correlate, inverted vertical or not.

The elements are 180 out of phase. The phase delay is 41 degrees plus 
the 180 degree inversion. The net phase **delay** of the feedpoint 
element end is 139 degrees. (Remember the NULL element is the phase 
reference, not the feedpoint!) 180-S is 146.5 degrees. The phase 
error is 146.5-139= 7.5 degrees.  

On 80 meters, the same EWE's spacing would be 67 degrees. The delay 
would be about 82 degrees. The phase delay of the feedpoint end 
would be 280-82= 98 degrees. The ideal delay would be 180-67=113 
degrees.  The error from ideal is 15 degrees.

When one element's feed is inverted the correct phase delay in the 
delay line for a backfire null is exactly equal to the spacing in 
degrees (spacing less than 1/4 wl). This is how I feed my 
four-square, my 40 meter beam, my loops and any other directional 
driven arrays.

Using this system phasing becomes frequency independent if a delay 
line (rather than lumped components) is used. I use the same delay 
line on 80 meters as on 160, and that delay line is the correct 
length all the way down to "dc".

For example, my loop arrays fire in the same direction at 100 KHz as 
they do at 7 MHz, with NO change in delay lines. They have the same 
direction response at 100Hz as at 100 KHz. The only thing that 
happens is sensitivity goes away. 

If the EWE system had a transmission line delay of 41 in the 
line (modeled value) and the spacing is 33.5 degrees, the error is 
only 7.5 degrees! That's not a large error.

73, Tom W8JI
w8ji.tom@MCIONE.com

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