WHAT IT IS

CIS-112 is the 112-carrier member of the Russian HF OFDM HDR ladder (45 / 60 / 93 / 112 / 128). Factory name unpublished. The number is the data-tone count after the preamble. It sits between the CIS-45/60/93 family page and CIS-128 / Corvette.

Burst and stream both exist. ID feature: a sparse 7-tone preamble, then a 56-tone half-fill, then the full 112-tooth grate, plus the family 3300 Hz pilot.

WHAT THE WATERFALL LOOKS LIKE

USB, ~2.9–3.0 kHz of teeth and a lone spike at 3300 Hz. Burst mode draws the preamble in three layers (I-56578):

1. All symbols for one symbol period.
2. Seven tones on channels 1, 7, 33, 49, 65, 81, 97 (step 16, ~410.25 Hz) for 19 OFDM symbols. Pilot is +6 dB vs this stage, +12 dB vs later data.
3. Fifty-six tones on the odd channels (~51.28 Hz) for 11 symbols, constant but different phases.

Then the 112-tone data fill. Stream mode drops to a two-part preamble and stays on. Logged examples: 20964, 15680, 10980 kHz USB.

HOW THE AIR INTERFACE WORKS

112 OFDM data channels. Spacing on the survey table 25.6 Hz. Per-tone rate 22.22 Bd. Burst book: π/4-DQPSK. Stream book also logged as BPSK at the same 22.22 Bd / 25.6 Hz. Ukrainian HDR table: DQPSK, ~2489 bit/s, 2.9 kHz. Pilot four channels above the top data tone, same 3300 Hz habit as CIS-12 and CIS-45/60/93.

Data phase includes “probe” symbols I-56578 reads as equalizer / sync inserts. Encrypted payload. No public factory decoder.

BANDS AND WHERE IT IS HEARD

HF USB 3–30 MHz. Same HDR / agency neighborhood as CIS-93 and CIS-128.

HARDWARE

Unpublished HDR modem. Clean 3 kHz USB path. Not AT-3004.

NOT THESE

CIS-45 / 60 / 93 — fewer tones, no 7+56 preamble dance.
CIS-128 / Corvette — 64 + dead centre + 64, often CIS-3000 in front.
CIS OFDM-121 — 121-channel burst grate, different layout.
CIS-12 — 12 PSK teeth at 200 Hz, same pilot only.

CAVEATS

“8 tones including carrier” vs “7 not including carrier” is the same preamble counted two ways. BPSK stream vs DQPSK burst are two books of one modem.

STATUS

Active HDR member. RadioReference still lists occasional UDXF hits into the mid-2020s.

IN ONE SENTENCE

CIS-112 is the Russian 112-tone OFDM HDR mode — 7 sparse tones, then 56 odd tones, then the full grate plus a 3300 Hz pilot, DQPSK or BPSK at 22.22 Bd — the rung between CIS-93 and CIS-128.