Re: [amsat-bb] This Weekend in Minneapolis: Central States VHF Society Meeting

["Andrew Glasbrenner" <glasbrenner@xxxxxxxxxxxxxx>]

Jim and all,

If I read things correctly Eagle will still carry a S-band beacon? It seems 
to me if we go to the trouble of including a transmitter and antenna, we 
might as well provide a little passband for those who don't have the 
interference issues? Even say 25 khz?

I read with interest accounts of people with interference on S-band, and I 
notice that there may be a common thread. Many of the antennas used for 
reception on AO-40, and even more used for AO-51 are not very effective at 
blocking sidelobes and thereby mitigating interference. It may be (and 
certainly is in my own experience) that successful weak signal S band HEO 
operation is going to require more than a BBQ dish and unprotected feed, or 
a helix wound on some PVC pipe. My own AO-40 downlink antenna was nearly 
immune from interference when above 15-25 degrees, including from the WAP 
and video sender in my own house. This was in an urban environment where I 
routinely could see 5-6 local WAPs on a wifi PC in the yard, and over a 
dozen with a gain antenna. My dish was very simple. 36" prime focus, with a 
homemade helix feed in a cup to reduce sidelobes. All of this was mounted 
with 70cm and 2m CP yagis on a G5500 on a roof tripod. The dish and homebrew 
feed and mounts cost less than 100$. Just another anecdotal data point for 
your consideration.

I understand that Eagle II is being considered as a close follow-on for 
Eagle I? Maybe there can be some diversity of modes between the two 
satellites, say U/V and S/C on I and UL/S and C/X? on II?

73, Drew KO4MA portable 6
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