Decode KAFT with an SDR

Group

KA family (own modes)

In the mode list

KAFT, 200 kHz - 1 MHz files

What KAFT is

KAFT: the file transfer mode of the KAAL family, 200 kHz, 500 kHz or 1 MHz wide (ten profiles from BPSK 1/4 to 1024-QAM 9/10, LDPC blocks with CRC-32, a hash check of the whole file). Receive follows the transfer and saves each verified file to a folder you choose; it only listens and sends no reply. Transmit sends a file one-way, repeated, to a radio or an IQ file.

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 KAFT, 200 kHz - 1 MHz files.

What OnAir shows

KAFT: the file transfer mode of the KAAL family, 200 kHz, 500 kHz or 1 MHz wide (ten profiles from BPSK 1/4 to 1024-QAM 9/10, LDPC blocks with CRC-32, a hash check of the whole file). Receive follows the transfer and saves each verified file to a folder you choose; it only listens and sends no reply. Transmit sends a file one-way, repeated, to a radio or an IQ file.

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 KAFT

More in KA family (own modes)