[amsat-bb] Re: J-Pole Antenna

[Gregg Wonderly]

Yes, any 1/2wave or 5/8 wave antenna system doubles the horizontal power by 
eliminating the power going up.  So, it is more like a donut in emission 
pattern, whereas the 1/4 antenna is a hemispherical (half a ball) emission pattern.

With satellites, you clearly need to go "up".

As has been said many times, most satellite passes are never "directly 
overhead", but rather on some inclination across the sky.  A 5 element yagi 
antenna, at a 35 degree angle from the horizon, with only an asmuth rotator, 
will let you work far more satellites for the money spent.

Gregg Wonderly

On 5/12/2013 12:48 PM, Jeff Moore wrote:
> I wouldn't recommend a J-pole for satellite work unless you expect to only work
> sats on the horizon.  The J-Pole antenna has a low take-off angle and almost NO
> radiation overhead,  an plain 1/4 wave ground plane antenna would work better
> for the sats.
>
>
>
> J-poles are great terrestrial communications antennas, not so much for working
> overhead satellite passes.  An Eggbeater or quadrifiliar antenna would be a
> better choice.
>
> 7 3
>
> Jeff Moore  --  KE7ACY
>
> On 5/12/2013 8:00 AM, Werner, HB9BNK wrote
>> Thank you all for your valuable hints and advices !
>>
>> I will now build such an antenna and then supply here the results.
>>
>> 73 Werner, HB9BNK
>
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