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Harris wideband operations (a bit "intruding" within the 7 MHz HAM band)
Wideband activity was heard at the end of August around 7 MHz (figure 1) using mainly Romanian and Greek KiwiSDR receivers, my friend KarapuZ sent me his recordings which are of a much better quality...
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OFDM-48 and some comments about OFDM analysis with SA
I wanted to further investigate the OFDM-48 signal published a few days ago [1], in particular the "mode" of construction of the signal and consequently the correct PSK modulation used in the channels....
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coastal HF Radars' embroideries
Interesting and in some way curious recording sent me by my friend "Sigurd from Netherlands". By varying the db level of the spectrum it is possible to see that actually the "embroidery" is composed of...
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R&S GM2100/2200 waveforms' preamble and its similarity to Link-11 SLEW
Me and my friend ANgazu from radiofrecuencias.es have recently studied curious, and apparently unid, burst transmissions occurred for about two consecutive days (7-8 Sept, ceased on 9 morning) on 12431...
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unid 150-300Bd/500 FSK
 (updated)Since some days me and my friend Cryptomaster are discussing an FSK signal detected on 6511.50 Khz (CF). Transmissions starts (and ends) with a long reversals sent at 150 baud speed followed...
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unid 150-300Bd/1000 FSK (150-300Bd/500 same system?)
 This FSK signal has the same characteristic switch of the modulation speed (150Bd during reversals, 300Bd in traffic mode), but a different shift (~1000Hz instead of ~500Hz), compared to the one seen...
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Harris' 3G-ALE FLSU Async call: a 141B/STANAG-4538 optimised implementation?
I recently had the chance to study some good quality recordings of (certified) Harris 3G-ALE Asynchronous calls and surprisingly I found some features of implementation derived from the now superseded...
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Harris' 3G-ALE FLSU Async call (2)
Commenting the recent post about the Harris's implementation of the FLSU Async call [1], an anonymous reader sent me a good quality recording of that signal. Observing the spectrum/time FFT of figure 1...
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Deep WALE (4G-ALE) Async call
Thanks to my friend and collegue ANgazu, I was able to analyze some WALE (4G-ALE, 188-141D App.G) asynchronous calls transmissions which reveal some aspects that are not entirely clear or even a bit...
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WALE (4G-ALE) three-way traffic channel negotiation
This post can be considered a continuation of the previous one since it too is based on the observations and analyzes of the same monitoring file.Also in this case these are asynchronous calls but with...
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an enhanced design for Deep & Fast WALE preambles (RapidM RM12 HF modem?)
This post briefly summarizes the analysis of the Deep & Fast WALE waveforms seen so far, discussing in particular the acquisition preambles whose formation does not comply with the reference...
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WALE & wideband traffic, probably RapidM proprietary WB-LDL & WB-RDL waveforms
My friend ANgazu and I are almost done going through nearly 30GB of recordings of broadband transmissions that took place in the portfion of 6.9-7 MHz band during October and November, monitoring was...
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a curious AT-3400D/AT-3104 (CIS-12) modem configuration
Interesting catch of an AT-3400D modem (also known as CIS-12 or MS-5) running on 14344.0 KHz/USB with the quite uncommon 9 channel configuration (3-out-of-12) as shown in Figure 1 belowFig. 1CIS-12, as...
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1200Bd/800 Russian tactical datalink
Interesting 1200Bd/800 "FSK" (apparently) transmissions spotted and monitored on 7980.0 KHz/usb from monday feb. 28th until march 2nd when it disappeared. The heard signal is a Russian "tactical data...
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a curious AT-3400D/AT-3104 (CIS-12) modem configuration
Interesting catch of an AT-3400D modem (also known as CIS-12 or MS-5) running on 14344.0 KHz/USB with the quite uncommon 9 channel configuration (3-out-of-12) as shown in Figure 1 belowFig. 1CIS-12, as...
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4529.75 KHz (cf), yet another async 5N1 STANAG-4481F (to replace 4539.7 KHz?)
Some days ago my dear friend Karapuz noted the transmission of STANAG-4481F segments centered on 4529.75 KHz, data were transferred using 5N1 framing and apparently not in clear text. In the following...
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unid ASK2/OOK transmissions
Unid transmissions heard on 8120, 8130, 8140, and 8150 KHz (the latter moved to 8160 Khz) thanks to the KiwiSDR located at N4BUT Orlando, FL [1].Fig. 1At first sight the signal seemed a MPSK...
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unid "mixed-mode" transmission
 Very interesting "mixed-mode" transmission cathced and sent me by by friend Michel (F1GOC)Fig. 1Segment 1 consists of an FSK modulation keyed at 200 Baud and 1000 Hz shift (Figure 2). The demodulated...
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RapidM proprietary WB-LDL & WB-RDL waveforms (2)
Thanks to a nice catch by my friend ANgazu from radiofrecuencias.es, who I thanks, it's now possible to add two other waveforms (#9, #11) to the Table II of the previous post [1]. The waveforms belong...
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unid 188-110A transmissions... and equally curious bitstreams
Some interesting transmissions were noticed last weekend on 5074.20 KHz/USB, transmissions consisting of continuous blocks of different durations and sent using the standard MS-110A modem with a fixed...
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