Decoding A Local TETRA Repeater With SDR# And TETRA Demodulator Plug-in (Terrestrial Trunked Radio)
TETRA is a popular UHF digital communication standard commonly utilized in various European countries and Australia. It is most often used in public safety or commercial environments and has not been adopted in the United States.
In Australia, or more specifically my place of residence, TETRA repeater outputs can be found from about 463 to 466 mHz. The TETRA standard allows for encrypted voice, but I am yet to encounter any encryption on these systems so far.
TETRA demodulator plugin for SDR Sharp is incredibly easy to use compared to the very clunky DSD plus. Set your mode as NFM with a 25 kHz bandwidth, tick the 'demodulator' box and the plugin handles everything else for you. Too easy!
I am not sure if it is the fault of the plugin, or just the nature of TETRA, but it seems to need quite a good signal-to-noise ratio to get reliable and clear voice decoding.
HARDWARE
Airspy R2 Software Defined Radio
25 Element 477 mHz Yagi Antenna
LMR400 Coaxial Feedline
SOFTWARE
SDR Sharp 1702
TETRA Demodulator Plug-in
