Category Archives: transponder

Es’hail-2: Hams Get Their First Geosynchronous Repeater

In the radio business, getting the high ground is key to covering as much territory from as few installations as possible. Anything that has a high profile, from a big municipal water tank to a roadside billboard to a remote hilltop, will likely be bristling with antennas, and different services …read more

Continue reading

Posted in amateur radio, AMSAT, DATV, Engineering, geosynchronous, Hackaday Columns, ham, Hams in Space, OSCAR, Qatar, QO-100, repeater, satellite, space, transponder, wireless hacks | Leave a comment

Accidental Satellite Hijacks Can Rebroadcast Cell Towers

A lot of us will use satellite communications without thinking much about the satellite itself. It’s tempting to imagine that up there in orbit is a communications hub and distribution node of breathtaking complexity and ingenuity, but it might come as a surprise to some people that most communications satellites are simple transponders. They listen on one frequency band, and shift what they hear to another upon which they rebroadcast it.

This simplicity is not without weakness, for example the phenomenon of satellite hijacking has a history stretching back decades. In the 1980s for example there were stories abroad of …read more

Continue reading

Posted in interference, parasitic, radio hacks, satellite, transponder | Leave a comment