Mois : janvier 2015

unknown 2400Bd QPSK? datalink

Today a new? datalink is active on HF, probably modem experiments..
2x stations exchanging datas, sending 2 bursts each time & changing frequency from time to time..


The system seems to be a 2400Bd QPSK waveform, but notice the constellation isn’t too clean… Signals Analyzer shows an ACF of ~37.45ms and bursts are ~1.765s long in this working mode.
Both stations were strong in the mobile HF, middle east france, but one station was fading very quickly and sometimes not heard at all..

I wonder if this traffic is related to 10244u

Datamode heard on 18MHz & 7MHz, so far
Frequencies logged today:
18178.0 USB 1500z
18210.0 USB 1509z
18213.0 USB 1512z
18263.0 USB 1515z
18266.0 USB 1518z
18360.0 USB 1521z
18363.0 USB 1524z
7786.0 USB 1730z
7789.0 USB 1754z
7791.0 USB 1850z
7843.0 USB 2013z
7846.5 USB 2055z

Logged 21 jan 2014:
10348.0 USB 2210z
10360.0 USB 2230z
10368.0 USB 2318z


unid users of HF packet Q15X25

Upper part is a sample downloaded here
Lower part is from 6790.0 USB heard tonight
This net is a spanish speaking one, probably from Central or South America
I’m not sure if they are pirates or legits, I never succeed in decoding Q15X25 frames using that MixW software + its additional Q15X25dll.dll
Callsign heard in the past: BANDERA



2400Bd QPSK ACF=600ms

Continuous mode, PSK carrier at 1800Hz, ACF measured 600ms, QPSK modulation?

Spotted on 9389.0 USB & 9248.0 USB tonight at fair to weak levels
Already logged on 10718.0 USB, 18140.0 USB & 19304.0 USB