Keep in mind that anything susceptible to Pave Paws will also be subject to the APS-145 based on Hawk Eye and P3 aircraft, which operates a higher power anywhere in the world, typically at sea.
73 JI K1KSC
On Sep 17, 2006, at 12:01 PM, John B. Stephensen wrote:
PAVE PAWS is part of the ballistic missle defense system so it will remain active. We didn't allow for much loss between the U antenna and U receiver so the use of two receivers would require some changes.
73,
John KD6OZH ----- Original Message ----- From: RaySoifer@cs.com To: kd6ozh@comcast.net ; K3IO@verizon.net ; bod@amsat.org ; Senior- officers@amsat.org ; advisors@amsat.org ; eagle@amsat.org Sent: Sunday, September 17, 2006 15:21 UTC Subject: Re: [Advisors] Re: [eagle] Re: [Fwd: Re: S band and Eagle: an appeal for ahig...
In a message dated 9/17/06 3:08:03 PM Greenwich Standard Time, kd6ozh@comcast.net writes:
Path loss is 15 dB less at 435 MHz than 2400 MHz and antenna gain is 13 dB less. However, the noise figure is 5 dB higher, so almost twice the EIRP wll be required on a U uplink than an S uplink. The 70 cm receiver has a 200 kHz bandwidth so some class 2 (4800 bps) uplinks could be accomodated. Since they will be BPSK and use FEC, I assume that they will occupy at least 15 kHz each and will have to be spaced at least 25 kHz apart. This could allow 4 uplinks. It's not good to increase the receiver bandwidth as it will let in more PAVE PAWS interference.
John,
I was thinking in terms of an additional 70 cm receiver to accommodate several conference-grade channels, for those users who may be prohibited from using BOTH L-band and S-band uplinks (think Europe). Yes, PAVE PAWS is there, sometimes, but it would still be better than no digital access at all. Also, it's not a certainty that PAVE PAWS will even be there in 2020.
73,
Ray _______________________________________________ Via the Eagle mailing list courtesy of AMSAT-NA Eagle@amsat.org http://amsat.org/mailman/listinfo/eagle