[amsat-bb] Re: J-Pole Antenna
w5ggw at cox.net
Mon May 13 07:25:43 PDT 2013
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.
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
> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
More information about the AMSAT-BB