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Re: Prefered AO40 Transmit Antennas ?



I used to get perfectly acceptble signals with 5 watts into a 44 el 
m-squared cross yagi.  (7 w into feedline)  SSB took 10 to 15 watts.

73,
Jim
wb4gcs@amsat.org


Michael Kjorling wrote:
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> On Jun 28 2003 10:40 +1000, Peter Moscatt wrote:
> 
> 
>>What is generally used for the 70cm uplink and what would the typical
>>gain need to be for a good link into AO40 ?
> 
> 
> I don't know if it is the "generally used" uplink antenna, but I am seriously
> considering a simple 70 cm (RHCP) helical antenna for my station. According
> to AMSAT-SM, 200 W EIRP "is enough", but they don't state if that is for SSB
> or CW. That is 10W into a 13-element X-Yagi, or 50W into a 4-turn helical
> antenna, if their web page can be trusted (which I hope!). Of course, the
> exact gain you need will be a function of how much power you can feed to the
> antenna at 70 cm! I, for one, only have 5 W at 70 cm, minus cable losses, so
> the four-turn helical won't cut it at all unless I get a 13-17 dB PA
> (reasonable cable losses and some margin figured in).
> 
> 
> Michael Kj–rling
> 
> - -- 
> Michael Kj–rling :: michael@kjorling.com :: SMÿYBY JO89  ^..^
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