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SCS/ALE: a 2G ALE Modem/Controller for DR-7400 and DR-7800 P4 modems
SCS/ALE controller (2G MIL 188-141 ALE) supports two modes: ALE/PACTOR, see the video below, and full stand alone ALE. In ALE/PACTOR existing PACTOR software needs to know nothing about ALE. The...
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playing with Arduino and a 12-bit LFSR
The circuit is just a test of the operation of the 12-bit LFSR x^12+x^6+x^4+x+1 used in 188-110A serial tone modems, in view of its full implementation; its software simulation has already been seen...
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an interesting start of a CIS-75 transmission
Interesting CIS-75 75Bd/250 FSK heard on 6404.0 KHz (cf): the encrypted data are preceeded by a sync sequence of reversals that - according to my measurements - is sent at the speed of 100Bd. Although...
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use PuTTY as Arduino monitor for LFSR circuits
Given the lack of really interesting signals on air, at least these days or no luck in hunting, I am playing with the semi-hardware (1) implementation of pseudo-random sequence generators: a way to...
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another approach to the analysis of unresolved sync sequences
The pseudo-random binary sequences (PRBS, also referred to as pseudo-random bit sequences) are largely used in telecommunication (data scrambling, sync sequences, field delimiter markers, jamming,...
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188-110A, D1 D2 patterns and interleaved blocks boundaries (hardware...
As well as to have some fun with ICs, I wanted to implement a part of the 188-110 modem to definitively understand the relationship between the periodicity of its bit stream and the lengths of the...
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MFSK-16 100Bd/100 transmissions, likely adaptive tests
Interesting MFSK-16 100Bd/100 transmissions spotted on 15810.0 KHz (cf) on August 27th, in the following days I tried several times to monitor that frequency, and more generally the 15 MHz band, but I...
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Ital-Mil 1200Bd/800 FSK
Short Ital-Mil 1200Bd/800 FSK used before STANAG-4285/HDLC QUEDRE [1]. The bitstream after demodulation exhibits a 232-bit period length and a bit more strutured patterns after differential decoding...
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async 5N1 STANAG-4481F, likely tests or training transmissions
Async (and episodic?) 5N1 STANAG-4481F "segments" spotted on 4539.7 KHz (cf): as a distinguishing feature, it's to notice the presence of a pilot tone at CF-700Hz (4539.0 Hz) preceding each segment and...
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75(50)Bd 4481F: yet another channel
Yet another 75Bd/50Bd 4481F channel spotted on 9338.0 KHz (cf), most likely from NPM Lualualei, HI (thanks my friend Mike "mco"). After filtering out the column of the replicated bits from the...
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2000Bd/3250 FSK on 26.9 MHz
Interesting FSK signal spotted on 26.9 MHz by friend killer258 from raduioscanner.ru: modulation speed is 2000 bps and 3250 Hz shift (figure 1).Fig. 1ACF results show a kind of "interleaved" values of...
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SDPSK 40Bd 50Hz OFDM-60 (60-out-of-61 + pilot tone)
OFDM signal heard on 5767.0 KHz (cf) and consisting of 61 channels plus a pilot tone located at the lowest frequency (thus 62 channels in all). The modulator actually uses 60 of the 61 available...
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unid 1200Bd/850 (G)FSK bursts recorded in Japan
This is an update of the January 9, 2019 post (see below)Nicely, on the same day two friends of mine linkz (from France) and Eddy (from South Australia) signaled me about the presence of these 1200Bd...
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19.5Bd/100 FSK: Rus R-397 “IRTYSH” (“ИРТЫШ”)
About one years ago (may 2020) I came across a short 19.5Bd/100 FSK [1] which, at that time, I chalked up to a some Russian-Mil network. Well, an anonymous reader of the blog, whom I thank, left a link...
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a strange (if not wrong) use of STANAG-5066
These days I am monitoring some signals on 5120 KHz (from Serbian-Mil) that will be the subject of a next post, and I noticed a strangeness in the use of STANAG-5066 in relation to the "way" the data...
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analyzing the HF network traffic on 5120 KHz (OS BiH)
First of all I want to thank IZ6BYY Alain from Martinsicuro (Italy) who allowed me to use his KiwiSDR receiver without time limits: I very appreciated. I monitored this Bosnian HF network (I logged...
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CIS MPSK-16, PSK2 500Bd
Interesting CIS transmission spotted by my friend KarapuZ, whom I thank for sharing. The signal is a wideband MPSK-16 waveform, with 2500 Hz channel spacing, and use a PSK2 modulation at the symbol...
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THALES HFXL modem, "SALAMANDRE" tests go on (2)
Thales HFXL modem tests spotted by my friend Geoff (who kindly sent me his recordings) on the upper limit of the 6 MHz band. In these tests the modem is able to use 16 contiguous(!) 3 kHz channels...
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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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THALES XL modem, channels time lag
Thales HF XL SALAMANDRE (1) test transmissions spotted by my friend Geoff (who kindly sent me his recordings) on the upper limit of the 6 MHz band. In these tests the modems are able to use 16...
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