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CIS-1200 DBPSK 1200Bd ("Makhovik", T-230-1A)
Good quality CIS-1200 (T-230-1A, DBPSK 1200Bd) transmission spotted on 9073.80 KHz (cf) thanks to the ArcticSDR. The transmission consists of a series of encrypted messages, the 240-bit Initialization...
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Rus 75Bd/200 FSK (T-208)
During the last week I have been monitoring the 75Bd/200 FSK transmissions (T-208 equipment) on 9044.0 Khz (CF): transmissions are on-air during daytime only, are encrypted (likely linear encryption)...
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3 x 250Bd/500 FSK, likely Ukr nets
3 x 250Bd/500 FSK channels, probably Ukrainian-Mil broadcast, already met here in october 2020. This sample shows a 334-bit period with interesting preambles consisting of a repeated pattern followed...
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a long (and protected) FLSU async scanning call
STANAG-4538 async call of FLSU protocol consists of the transmission of 1.35N (nearest integer value) Request type 3 PDUs on the requested link frequency, where N is the number of channels in the scan...
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unid secondary protocol
Recently I ran across on several transmissions in the 5 MHz band (also available on a secondary basis for amateur use) consisting of STANAG-4538 point-to-point circuit mode service with 188-110A (300,...
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Arcotel-MAHRS 2400 serial
The so-colled Arcotel-MAHRS 2400 is a 2400Bd PSK-8 serial waveform with simmetical 2 x 8 pre-tones in respect of the 1800Hz carrier. The signal has strong 106.66ms ACF spikes (256 tribit symbols) due...
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CIS Navy FSK 50Bd/250 (T-600)
50Bd/250 FSK is another waveform used by CIS Navy for their fleet broadcast. Unlike the same waveform but with 136-bit framing (T-600 136), this one shows all the characteristics of the (perhaps more)...
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unid, and somewhat peculiar, 1200Bd DBPSK
Cleaning up one of my hard disks I came across an old recording (year 2014) that had no comment file associated with it, so I decided to take a look at it and see what exactly it was. The recording...
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Canada's East Coast Navy STANAG-4481P broadcasts
STANAG-4481 PSK (4481-P) waveform carrying the KW-46 secured fleet broadcast of the Canada's East Coast Navy. STANAG-4481P is basically a STANAG-4285 sub-mode which adopts fixed 300 bps data-rate and...
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yet another STANAG-4481F 50-75Bd broadcast
5716.0 KHz (cf): STANAG-4481F (apparently) 75Bd fleet broadcast from NAU Isabela (PTR), running with the "odd" and already observerd 3-bit format (Figure 1).Fig. 1 Removing the third column which...
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UK MoD 12800bps bursts: other oddities
I was just monitoring some interesting sequences of 2400Bd PSK bursts occupying 3 out of 6 channels (each 3 KHz width) according to alternate timings of 40 and 20 seconds: frequencies 5742.5, 5748.5,...
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188-110A, ACF lengths and interleaved blocks boundaries
MIL 188-110A, unlike other waveforms such as STANAG-4539 or STANAG-4285, does not always show the same ACF value as the data rate changes: it is mainly due to the variations of the frame structure...
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Three new fleet broadcast channels
Three new fleet broadcast channels spotted in these days, all STANAG-4481F: 4987.0 KHz (cf) 50Bd from NSS Davidsonville7455,5 KHz (cf) 75Bd from NSY Niscemi7457.0 KHz (cf) 50Bd from NAU IsabelaAll the...
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MAHRS-serial and STANAG-4285, ie don't blindly trust decoders
It happened by chance to analyze a complete session of data exchange in MAHRS mode (ALE + traffic) while I had a STANAG-4285 decoder in active state on the desktop: to my surprise the decoder started...
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a STANAG-4481F temporary channel activation?
Heard 75Bd/850 FSK transmissions (broadcasts?) on 6372.0 KHz CF until sunday 13th June, no transmission in the following days (at least until today). Transmissions were KW-46 secured and sourced most...
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3G-HF "BW5 + 110A" combined waveform ...or just coincidence?
From 19 to 23 June I monitored interesting transmissions on 5091.5 KHz/USB that seem to use a kind of "combined" waveform which consists of FLSU BW5 waveform followed by 188-110A 300bps waveform. For...
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unid FSK/MFSK SELCAL
6907.0 KHz (cf): unid SELCAL waveform spotted on 6907.0 KHz (cf),. The waveform consists of 40Bd/240 FSK idling part followed by MFSK-36 40Bd/40 (likely the Id of called station).Fig. 1 Fig....
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8N1 async operations
8N1 async operations using STANAG-4285 and 110A Serial modems (1200bps/S, 1200bps/L respectively) recorded on 6.9 MHz band, the first likely from Turkey. After the removal of the framings, the 8-bit...
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unid STANAG-4539 3200bps bursts
Interesting and unid STANAG-4539 bursts recorded on 5270.0 KHz/usb. The user data rate is 3200 bps and is obtained using QPSK modulation, short interleaver is used. Notice that the quadrature...
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tools to generate 188-110A channel probes... and not only them
I recently checked the 188-110A transmissions - referred to in this post - characterized by a secondary protocol not (yet) identified, the purpose was to verify if in the meantime some novelties had...
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