Jan 9, 2010

Amateur Radio Satellite Communication : An Introduction


One of the aspects of the Amateur Radio hobby is the use of Low Earth Orbit (LEO) satellites for communications. These are satellites placed in orbit for Amateur Radio use. These satellites pass over the earth with durations for effective satellite communications of an average of 10 minutes for a given location. During this time Amateur Radio operators (Hams) can communicate through the satellite to other Hams who are under the same satellite footprint.
More information is available at http://www.amsat.org/
For best satellite communication it is important to use a directional antenna system that is pointed at the satellite position and tracks the satellite’s position as it travels through space.

Communication satellites called OSCARs (Orbiting Satellite Carrying Amateur Radio) can be accessed, some using a hand-held transceiver (HT) with a factory "rubber duck" antenna. Hams are also often able to make contact with the International Space Station (ISS) as many astronauts and cosmonauts are licensed as amateur radio operators.

AMSAT India – Indian Amateur Radio Satellite Programme

AMSAT is a worldwide group of Amateur Radio Operators who share an active interest in building, launching and then communication with each other through non-commercial Amateur Radio satellites. By any measure, AMSAT's track record has been impressive. Since its initial founding over 25 years ago, AMSAT has predominantly volunteered labor and donated resources to design, construct and with the added assistance of government and commercial space agencies, successfully launched over two dozen Amateur Radio communications satellites into the orbit of Earth. Sharing the same vision and objectives, other like minded groups throughout the world have since been formed to pursue the Amateur Radio Satellite program.
A HAM below with a handheld radio & simple three element antenna catching the sattelite signal outdoor.

A sophisticated setup with a automatic antenna rotator which is connected to the sattelite tracking software and keep aligning as satellite moves.



One of the popular web based
Indian HAMSAT satellite live tracking software, it tracks your internet IP and gives your latitude/longitude also in comparison with satellite's current position as well future appearance time windows.


HAMSAT Downlink - VHF 145.900 MHZ can be listed when sattelite is in Indian range with simple VHF setup, but window would be 5 to 10 minutes max or lesser unless you can have a moving antenna.
HAMSAT Uplink - UHF 435.250 MHZ
The best equipment is a handheld dual band VHF/UHF transreceiver like the Wouxun KGUVD1 and a handheld external antenna.

An artists impressions of satelite in space.

AMSAT India were responsible for the Amateur Radio satellite HAMSAT 1 (VO-52) launched on 5th March 2005 and they are currently working on it's successor HAMSAT 2.

Further information on VO-52 can be found at
http://www.amsat.org/amsat-new/satellites/sat_summary/hamsat.php

HAMSAT (VO-52) - N2YO Real Time Satellite Tracking
http://www.n2yo.com/?s=28650

AMSAT India sponsors VO-52 Operating Certificate

2 comments:

  1. My dear fellows,
    VO52 has a linear inverting transponder in Mode B. Wouxn is a dual band HT with 5 khz tunig steps in FM mode only. Please refer Amsat description of modes for VO52- It is either CW or SSB. If u are using FM mode on a inverting transponder u are running down the battery of the transponder fast,there by the life of the satellite.No where else FM is used .Please desist from using FM on VO 52 lest we VUs be listed as LIDS

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  2. how many passes will the satellite hamsat make over chennai?

    ReplyDelete