WHAT IT IS

CIS-1200 is the monitoring name for a single-carrier 1200 baud PSK HF waveform. The factory name is T-230-1A «Маховик» — Mahovik, “flywheel.” IARU cards also print T-230 and “CIS Makhovik.”

Two different things share the Mahovik label and that is why wiki pages glue this mode onto CIS-12:

T-230 is a rack suite: AT-3002M LF multi-channel modem, AT-3004D HF modem (the CIS-12 comb), AT-3001M voice scrambler (up to five), AT-3025 signaling / pager (up to two). On HF that suite looks like CIS-12 because the AT-3004D is in the slot.

T-230-1A is the single-channel field set: cipher, modem, radio and vocoder in three modules. Basic fit is two 1200 bit/s channels. Eight keys, eight subscriber nets. Several 1A boxes can sit behind a multi-channel AT-3002 / AT-3004D in a fixed station. The air picture of the 1A on its own radio is one fat PSK carrier at 1200 Bd — this page — not twelve teeth.

Precious-metal inventories list T-230-1A as засекречивающая аппаратура (secrecy apparatus). That is the factory category. The waveform is how that box leaves the antenna.

WHAT THE WATERFALL LOOKS LIKE

On USB:

— One wide PSK slab, about 2.1–2.5 kHz across. Not a comb. Not twelve bars. Not a 3300 Hz pilot.
— Grain is 1200 Bd BPSK or SDPSK — much faster shimmer than a 120 Bd CIS-12 tooth.
— Autocorrelation on traffic cards: about 426.66 ms / 512 bits.
— If you see twelve parallel tracks plus a 3300 Hz whistle, you have CIS-12 (AT-3004D in a T-230 rack or standalone). Come back to this page only for the single slab.

Sound: a harsh mid-band buzz, one lump, not a fence.

HOW THE AIR INTERFACE WORKS

Monitor card:

— Modulation BPSK or SDPSK (symmetric differential PSK)
— Symbol rate 1200 Bd
— Occupied width ~2.5 kHz (IARU also prints ~2.1 kHz)
— USB, HF 3–30 MHz

1200 Bd × 1 bit (BPSK) = 1200 bit/s on the air — the same number as one AT-3004D book rate and as one of the 1A’s two baseband channels. SDPSK is the other logged constellation; same baud.

Open analyses of recordings (I5-56578 / Radioscanner) find a repeating structure that also rides CIS-12 when Mahovik is the payload cipher: short frame-sync, a 511-bit block matching the ITU O.153 polynomial family used for sync / error measurement, and a 30-bit message indicator repeated in triplicate (a 720-bit MI block in the CIS-12 arrangement). Arrangement differs between the 12-tone pipe and the 1200 Bd pipe. That is identification of a suite, not a public decode of traffic.

WHAT TRAVELS ON IT

Voice (vocoder in the 1A) and data / teleprinter. Cipher is in the box before the modem. Hobby tools ID the mode. They do not read the order. T-219 «Яхта» (Yachta) is the related voice-scrambler name that Sigidwiki cross-links; treat it as the same secrecy family, different faceplate, until a separate page exists.

BANDS AND WHERE IT IS HEARD

HF USB. Catalogue 3–30 MHz. Published example spots: 7290, 9073.8, 13002.5 kHz. Same day-night HF habits as the Almaz combs. The 1A can also feed an AT-3004D; then the waterfall becomes CIS-12 and this page no longer applies.

HARDWARE

T-230 — multi-slot suite. HF look = CIS-12 when AT-3004D is fitted.

T-230-1A — three-module single-channel set: cipher + modem + radio/vocoder. Two 1200 bit/s channels in the basic configuration. Eight nets. Listed in Soviet/Russian precious-metal communication-gear registers as secrecy apparatus (gold/silver/platinum inventories exist; they prove the NSN, not the PHY).

No public hobby decoder. Wavecom / professional kits that ID “CIS-1200” stop at the constellation.

NOT THESE

CIS-12 / AT-3004D — twelve 120 Bd tones + 3300 Hz pilot. Often the HF slot inside a T-230 rack. Different waterfall.
CIS-20 / CIS-16 — still combs.
CIS-3000 — 8-PSK ~3000 Bd class, different modem line.

CAVEATS

“T-230” on CIS-12 wiki lines is the suite, not this single-carrier mode. Bandwidth 2.1 vs 2.5 kHz is card scatter. 511-bit / 30-bit MI notes are monitor analyses of recordings. Example frequencies are spots, not an allocation table.

STATUS

Active in the HF corpus. The 1A is the field face of Mahovik; the rack T-230 is why CIS-12 and this page keep getting filed in the same drawer.

IN ONE SENTENCE

CIS-1200 is the single-carrier 1200 Bd BPSK/SDPSK HF picture of the T-230-1A Mahovik secrecy set — a ~2.5 kHz slab with no 3300 Hz pilot — while the parent T-230 rack puts an AT-3004D in the HF slot and then looks like CIS-12.