RE: [amsat-bb] Re: new 5.8ghz cordless phones

["Tom Clark, W3IWI" <w3iwi@xxxxxxxx>]

The comment was made ....

>Looks like if everyone went to 5.8GHz our AO-40 reception would be free ...

True, in the short term, but perhaps bad news for the future.

Regarding C-Band, I note that in the ITU frequency allocation tables,
 - the band 5650-5670 MHz is marked "Amateur Satellite Service, Secondary,
Worldwide, Earth-to-Space" and
 - the band 5830-5850 MHz is marked "Amateur Satellite Service, Secondary,
Worldwide, Space-to-Earth".

This 2x20 MHz pairing could be one of our most valuable resources in future
satellites. I can envision an in-band transponder with a single 5750 MHz
Local Oscillator. This would swap the sidebands and be an inverting
transponder, which would cancel out the bulk of Doppler shift. Both
satellite and ground user could employ a single dish antenna for both uplink
and downlink (using opposite polarizations). A standard "BUD" (big ugly
dish) TVRO antenna would provide enough gain so that very little TX power
would be needed, even to achieve up/downlink bandwidths of several MHz.

But if the 5.8 GHz telephone and 802.11a QRM gets too bad, ideas like this
could become unfeasible.

73 de Tom, W3IWI




----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org