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Re: Helix Match



Hi Richard , Gang

Thanks for the reply.    Reading the groups comments has been good for
what ails me .      My curiosity was relative to how the circular
polarization held up .      Not knowing about the reflectors ( single or
separate ) provided a hole in my thinking process.      Your thought on a
single wire above the reflector adds interest to my train of thought.    

All of my indeavor with the helix for several years has been relative to
a monofilar axial-mode prime feed antenna for a dish antenna.    All of
my work has been on the 2.4 gHz band.     With the advent of P3D I  have
a desire to make a dual band helix ( 1268 and 5670 mHz ) for a 54 inch
dish .     I have had good success with the single band helix prime feed 
for many years.     Many states and countries work / confirmed via
satellite.      Some of the current thread has caused the thinker to
awaken again.

So if you can provide any insight on the effect of having two separate
reflectors I'd be grateful.     How far apart the centers of the
reflector are?    Any knowledge of the overall beam pattern.     Any
polarity sensing measurements .  


Your thoughts on the matching may lead to methods of a two band helix
feed .     Concentric or offset helix may be considered.   

Thanks again 

Joe Murray   K0VTY    
Amsat # 0860

On Thu, 27 Jan 2000 18:24:10 GMT Richard@g3rwl.demon.co.uk (Richard W L
Limebear) writes:
>Joe, Gang,
>
> joseph v murray writes:
>
>> A question if you have time on your interesting matching of two 
>helix.
>> Was the reflector a single or did both helix have separate 
>reflectors.
>
>Separates. Circles of chicken wire (about half-inch mesh).
>
>I think I see what you're aiming at; sure - a wire, at the right 
>distance
>from a common reflector, could be used as a feedline.
>
>73
>Richard W L Limebear G3RWL
>g3rwl@amsat.org
>FOC # 1188
>
>          So many beautiful girls ..... (sob) so little time
>----
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