[50mhz] Ground gain vs antenna polarization

[Lance Collister, W7GJ]

Hello Ray,

TNX for your email.  That may well explain why the lobes from the two different 
polarizations differ in elevation, given the same antenna height above ground.

In answer to your question, Lionel currently has no antennas, and is not active on 
VHF anymore.  He still keeps his "toe in the water" through his extensive antenna 
modeling and comparisons:

http://www.bigskyspaces.com/w7gj/6mTable.htm

I wish I had a good place to mount a cross polarized 3 element yagi for 6m so I could 
experiment with this.  You would have to end-mount the yagi, but I would think it 
could probably be possible with something like a small 3 element beam as long as it 
was well trussed with non-conducting lines.  In order to minimize the unequal ground 
gain btween the two orthagonal polarities, I think it would be best to orient the 
antenna with the elements in an X configuration so that variable would be removed. 
Hmmmm...yet another project!

GL and VY 73, Lance


On 6/27/2011 8:55 PM, Rsoifer at aol.com wrote:
> Paul and Lance,
>
> Does Lionel still have an antenna whose pattern can be rotated in the Z axis? If so,
> maybe the effect can be measured.
>
> I believe that, to a first approximation anyway, ground reflection from a horizontal
> antenna is phase inverted 180 degrees, while that from a vertical antenna is not.
> That would obviously affect the pattern.
>
> When I was on 2 with a horizontal CC3219 at 30 feet, my ground reflection lobes were
> at 3.5 and 10.5 degrees, with a weaker one around 17 degrees. Those tracked pretty
> well with the model.
>
> 73 Ray W2RS


-- 
Lance Collister, W7GJ
(ex WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 3D2LR, 5W0GJ)
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2m DXCC #11/6m DXCC #815

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