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Macintosh Amateur Radio Satellite Tracking Software

VE3VRW MacDoppler Gateway...

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Hundreds of Hams in Southern Ontario and Western New York have been using the VE3VRW Satellite Gateway via the SSPBD Repeater System to make contacts on AO-27, UO-14, Sunsat, SO-41, SO-50, Echo, Mir and ISS since it was first installed in 1997.

MacDoppler automatically tracks an unlimited number of prioritized satellites 24 hours a day 7 days a week, completely unattended, controlling a Kenwood TS-2000 to correct for Doppler on all modes and pointing antennas through a Yaesu GS232 and G5400B combination.

Speech advisories are synthesized on the fly (rather than "canned") with upcoming pass information, elevation and uplink frequency reminder, and are converted from ASCII text to speech and transmitted through the link radio on multiples of 60 minutes before AOS, 30 minutes, 15 minutes, 5 minutes and when the program switches to a new satellite. Daytime passes of AO-27 are skipped if they are known to be inoperative.

MacDoppler makes use of the Ontrak ADR101 to key the link radio PTT during passes and advisories and to "listen" to the COR to stop satellite voice advisories from stepping on QSO's in progress.

The "Control: COR PTT" line is actually 2 lines - 1 from the TS-2000 to put the link radio into transmit when there is either a synthesized voice advisory from the computer or the TS-2000 is receiving something (unsquelched).

The line from the (slightly modified) link radio to the ADR101 allows MacDopplerPRO to tell if the repeater system is busy (IC-38A unsquelched) and to wait until it is not busy before sending out the synthesized voice advisories.

All the logic to do this in included in MacDoppler when the 'Gateway' option is selected.


Antennas:

Band Manufacturer Part Description
UHF M2 436CP30 30 Element Circular Polarized 14.15 dBdc gain
M2 Polarity Switch
SSB SP7000 Preamp 10-20 db gain, helical filter
VHF M2 2MCP14 14 Element Circular Polarized 10.20 dBdc gain
S Andrew 26T-2400 Grid Antenna
(reflector mesh added)
SSB UEK-300 S/VHF Downconverter