think about it, the percentage shift of the carrier frequency of the modulating tone compared to the carrier will be negligible and therefore the effect on the tone itself will also be virtually zero. If the Doppler affected it significantly, our voices through the system would also be changed significantly. Also, packet wouldn't work either and we know that it works fine.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of MM Sent: Wednesday, 2 May 2007 22:42 To: [email protected]; [email protected] Subject: [sarex] Future ISS amateur radio modes, Marex
ISS Amateur Radio Status: May 2, 2007
Future Projects on ISS By Miles Mann WF1F,
MAREX-MG News www.marexmg.org
Manned Amateur Radio Experiment
Future Projects on ISS:
There are a lot of good ideas regarding how to use Amateur Radio equipment on board ISS. I like the suggestion from Darrell Bellerive va7to of using a Downlink PL tone from ISS for the voice channel.
I am not sure how much the Doppler will affect the PL tone. I am intrigued by the idea and will try some terrestrial experimentation to if there is much of an effect.
Current In-flight projects on ISS include: Packet, Voice (mono-band), Cross-Band Repeater and SSTV.
Each of these projects has shown good results from manned platforms such as Mir and ISS. The projects that the space agencies like the best are the ones that do not use very much crew time. The projects Packet, Cross-Band and SSTV are the highest bang for the buck projects because they do not take up too much crew time. And as we know, free crew time for ham projexts is very very limited.
Cross-Band Repeater generates a lot if good interest from the amateur radio community. There are a few down side issues to cross band that have to be taken into consideration. Not all countries allow amateur radio on the 440 band (sometimes called 70cm). There is more Doppler on 440 (+ and - 10khz) Some of these and other issues can be overcome with experience. I wold be nice if someone could design a small frequency agile cross repeater that could work on any combination of 10 meter, 2-meter and 440. That way we would have the maximum flexibility based on project needs. We have the existing antennas on ISS, let's use them.
Existing ISS Antenna counts: Module FGB One Sirius 2-meter antenna tuned for approximately 147 MHZ. Dual one-quarter wave co-phased antennas mounted externally. Currently connected to the Ericsson Ht.
Service Module, Three Tri-Band antennas, that support 2-meters, 440 and a patch antenna supporting 1.2 - 2.4 GHz. (The patch antenna has high coax losses, > 8 dB at 1.2 GHz) One 10-meter whip and 1.2-2.4 GHz patch combination. One of these Tri-Band antennas is conneced to the D700. The others are not currenlty used.
Grand total of currently installed Amateur Radio antennas on ISS 4 antennas for 2-meters 3 antennas for 440 4 antennas for 1.2-2.4 GHz 1 antenna for 10 meters
MAREX is focusing on the entry-level projects for beginners such as Slow Scan TV and Packet Email. We have had excellent results on Mir project with both SSTV and Packet. And last summer experimented with SSTV from ISS with some very good down linked images.
The long term plans, hardware and crew time permitting is to place SSTV on a 10 meter down link, continuously streaming images from ISS. http://www.marexmg.org/imagessstv/SpaceCamImages1.htm
And place a continuous presence Packet Email system on 2-meters, running 24/7. MAREX has received initial approval to use a Kantronics KPC-9612 TNC as the data engine. This modem supports all the standard features of most TNC's built, including: Full Multiple user simultaneous Email users. Simultaneous dual speed support 1200 and 9600 baud. Un-proto modes, Text messaging and APRS beacons.
Some unapproved projects Marex is working on are to provide a full plug and play solution for a new system. New style easy to use transceivers, Analog and digital voice capabilities, Bolt on heat sinks and fans to compensate for zero gravity cooling issues, standardized plug in DC headsets and more. Your support for these projects would be greatly appreciated. http://www.marexmg.org/
ARISS Web page and other great Space projects http://www.rac.ca/ariss/
73 Miles WF1F MAREX-MG
Until we meet again
DOSVIDANIYA Miles WF1F
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