[amsat-bb] Re: FW: ARLB013 ARRL aiding effort to mitigate repeaterinterference to military radars
kl7uw at acsalaska.net
Tue Apr 24 19:12:02 PDT 2007
Yeah, I thought about that. If your antenna has 20-dB gain, like my
eme array has, it has a 3-dB beamwidth of 20-deg. So at elev. 20 I
could transmit 10w and only have 5w on the horizon. Restricting my
satellite operation above 20-deg. would be needed. If you ran 25w,
you would be restricted to above 40-deg. But didn't someone say that
most satellite passes are below 40-degrees? How many folks use eme
arrays for satellites?
Now if you uplink on 5.7 GHz with a 3-foot dish then beamwidth is
4-deg. with 33-dB gain. Your EIRP is 5w x 2000 = 10 kw ...kind of
shows the advantages of mw for space comm.
I know I have definitely gone off topic...but it gives one something
to think about.
At 07:36 AM 4/24/2007, Margaret Leber wrote:
>On 4/24/07, Edward Cole <kl7uw at acsalaska.net> wrote:
>>Build satellites that require no more than 5w EIRP from the ground
>>station may be the only answer.
>Or transmit with a more directional antenna aimed skyward...which is
>not a practical solution for terrestrial repeaters.
>73 de Maggie K3XS
>Editor, Phil-Mont Mobile Radio Club Blurb - http://www.phil-mont.org
>Elecraft K2 #1641 -- AOPA 925383 -- ARRL 39280
Ed - KL7UW
BP40IQ 50-MHz - 10-GHz www.kl7uw.com
144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w
DUBUS Magazine USA Rep dubususa at hotmail.com
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