Mode TETRAPOL

TETRAPOL: control-channel system information (receive only).

Group	Two-way radio
Default frequency	392 MHz
Default sample rate	250 ksps
In the mode list	Network info, UHF

Step-by-step: Tutorial-TETRAPOL

What TETRAPOL is

TETRAPOL is a digital trunked radio system with its own air interface (GMSK, 8 kbit/s, 10 / 12.5 kHz channels, PAS 0001-2), different from TETRA. OnAir shows the network information the control channel broadcasts.

Frequencies and settings

TETRAPOL control channel (PAS 0001-2), GMSK 8 kbit/s, 10 / 12.5 kHz (not TETRA).

Setting	Value
Start frequency	392 MHz
Tuning range of the mode table	68 to 520 MHz
Sample rate asked	250 ksps
Lowest working rate	64 ksps
Channel width	200 kHz

OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is Network info, UHF.

What OnAir shows

D_SYSTEM_INFO: country, system, cell, location area, channel, scramble; receive only, no voice, nothing decrypted.

Tips and caveats

• Checked with generated signals and impairments; recordings of real signals welcome.
• Which radio: Usually yes for narrowband signals: an RTL-SDR tunes roughly 24 MHz to 1.7 GHz at up to about 2.4 Msps. Wide signals such as TV channels need a faster radio, and OnAir says next to the source what the selected radio can do.
• Try it without a radio: most modes include a built-in synthetic test signal, so you can open the screen and try the controls first.
• Receiving and the law: In many countries it is illegal to intercept or disclose private radio communications. OnAir is a receiver: encrypted calls show up only as encrypted and are never decrypted, and voice needs a library you install yourself. Follow the law where you live. See Legal.

Related pages

• Voice codecs
• All modes, Two-way radio
• Supported radios, Troubleshooting, FAQ
• More in Two-way radio: DMR, NXDN, P25, dPMR / PMR446, TETRA