karn@allegra.UUCP (12/07/83)
As part of the design effort for the PACSAT store-and-forward satellite, I would like to gather as much information as possible about all non-amateur users of the 420-450 mhz amateur band, in North America and elsewhere. Since it is currently planned to use this band (specifically the 435-438 mhz subband allocated to the Amateur Satellite Service) for the digital uplinks to PACSAT, I particularly need to know if interference from ground radar systems (e.g., Pave Paws) is likely to be a problem. In the past, amateur satellite transponders have used simple pulse blankers to suppress any radar interference, which has worked well with SSB and low rate data. However, PACSAT will carry PSK demodulators running at bit rates on the order of 9600 bps. At such speeds I suspect that there might be radars with pulse durations greater than one bit time. Specifically, I would like to know: Locations Frequencies in use Pulse shapes, durations and repetition rates Occupied bandwidth Peak power levels Antenna patterns Operating schedules (24 hrs/day, etc) Thanks, Phil Karn, KA9Q