@geoff_mcmaw Just by looking to the screenshot, it seems to be PACTOR IV with different speedlevels. On this frequency most probably sent by or to Sailmail Radio Brugge.
Example with sound: https://t.co/jZuW5eTCRn
15896.5 kHz - 1200Bd Packet Radio / AX.25 transmissions with TCP/IP packets during the last days. Callsigns were HQ2CEN and CE4TST. The file header in each transmission is showing a JPEG (JFIF) structure.
Recording: https://t.co/Q38iB7VlPC
@India_Papa_Golf @W6UNX Thanks for the recordings ! There is some clear text which should help us to identify the transmissions. The first file is about controlling a Raspberry Pi which seems to be used as a beacon, followed by a PNG image
@India_Papa_Golf @W6UNX KarapuZ, I see these numbers only as a part of the AX.25 header text but not as IP addresses. The only IP addresses I found were 1.1.1.1 and 1.1.1.2 (also recognized by UZ7HO soundmodem)
I'm still trying to extract the complete jpeg file, but I'm only getting broken images...
@priyom_org yes, the bytes between marker FF C0 and FF C4 are 00 11 08 01 04 01 5C 03 01 11 00 02 11 01 03 11 01
This would be a resolution of 260x348 px, if I'm not wrong
@i56578_swl nice catch, this protocol was also seen some years ago on 10201 kHz, at that time combined with ANDVT modem and clear voice
https://t.co/ZOx1XgJp9w
10201 kHz - Radio checks of callsigns "chieftain madness" and "nomad" (or similar) using voice, STANAG 4197 and MIL-STD188-110A
@i56578_swl - The secondary protocol is same like seen here: https://t.co/xMTkebwgD9
Recordings:
https://t.co/bXsmTJ5V78
https://t.co/BGGa04vyro
4744.5 kHz - Norwegian Navy stations LBJ and 3KD trying to send messages using STANAG-4481-PSK with KG84 encryption. But no success, even after confirming the use of "national crypto" several times.
Recording (voice and data): https://t.co/qqBmdtviXD
4485 kHz and 10608 kHz - (to me) unid periodic signal. Synched every 1.8s followed by eight slots of 200ms. Fragments of voice, mic feedback and MFSK-8 (ALE-2G ?) could be seen in the slots. Any idea ?
Recording: https://t.co/E5c8LNFEvn
6668 kHz - Chinese mil / People's Liberation Army (PLA) with several 3-digit callsigns sending MIL-110A with HARRIS Citadel encryption.
Recording: https://t.co/kMOeUEqdqi
6828 kHz, 5437 kHz and other freqs (tonight) - ALE-2G calls 10CDGD, DGG01D and DGD01D followed by MIL-110A transmissions with KG-84 encryption. Any idea who it is ?
Recording: https://t.co/xJu2r9CsGr