OnAirDecode SITOR (WIP, table unverified) with an SDR
SITOR: CCIR 476 teletype, work in progress; text may be wrong until the table is checked.
- Group
- Amateur: digital
- In the mode list
- Teletype, work in progress
What SITOR (WIP, table unverified) is
SITOR / CCIR 476 teletype (FEC-A and FEC-B) on HF: work in progress, no FSK demodulator yet, character table not checked against ITU-R M.476.
Frequencies and settings
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 Teletype, work in progress.
What OnAir shows
SITOR / CCIR 476 teletype (FEC-A and FEC-B) on HF: work in progress, no FSK demodulator yet, character table not checked against ITU-R M.476.
Limits and what it was checked with
Checked with generated signals and impairments; recordings of real signals welcome.
Which radio you need
This is a shortwave mode, so the radio has to tune HF. An SDRplay, Airspy HF+ or an RTL-SDR in direct-sampling mode do that directly; with a HackRF an HF upconverter or a direct-sampling receiver is the usual route. A long wire or loop antenna matters more than the radio.
Receiving and the law
Questions about SITOR (WIP, table unverified)
Can I decode SITOR (WIP, table unverified) with an RTL-SDR?
An RTL-SDR can receive HF only in direct-sampling mode, which OnAir offers in its radio settings; results depend on the antenna. SDRplay and Airspy HF+ radios are better suited.
Is it legal to receive SITOR (WIP, table unverified)?
Amateur radio signals are meant to be received. Receiving needs no licence in most countries; OnAir does not transmit.
Can I try SITOR (WIP, table unverified) in OnAir without a radio?
Yes. Most modes include a built-in synthetic test signal, so you can open the screen and try the controls before you own a radio.