ATCTech
Active Member
- Joined
- Aug 13, 2002
- Messages
- 1,857
I'm outside my usual modes and bands of interest with this one but having shared information with local amateur operators and come up empty I'll put this online to see if anyone recognizing it. For the last 2 or 3 months (maybe longer, but that's when I stumbled onto it), there are daily digital transmissions in my local area on 50.2625 MHz. Signal strength varies, but in a consistent way. Operation is typically weekday mornings (between around 7:00 and 8:30 AM local time) and evenings, plus random on weekends. Signal strength is solid and steady at S-9+ most of the time, but but there's also periods of highly fluctuating signal where there's little doubt the operator goes mobile. The typical pattern is the strong fixed level until about the last 20 minutes of use in the morning, as if he starts at home then goes mobile on the way to work. I've listened and watched on the SDR display many, many times and I see zero evidence of a responding signal anywhere in the 6M band, at any level.
I've searched high and low for audio samples of digital modes that sound like this, and tried a handful of decoding programs with no luck at all. Attached here is an audio sample just recorded. This is from SDR# with NO audio filtering. The first burst was recorded in FMN, the second in AM, the last in SSB.
Should anyone have an idea what it might be (and how to decode it) or would like me to do another recording with specific filters/mode etc. to narrow it down please ask!
Cheers!
Bob
I've searched high and low for audio samples of digital modes that sound like this, and tried a handful of decoding programs with no luck at all. Attached here is an audio sample just recorded. This is from SDR# with NO audio filtering. The first burst was recorded in FMN, the second in AM, the last in SSB.
Should anyone have an idea what it might be (and how to decode it) or would like me to do another recording with specific filters/mode etc. to narrow it down please ask!
Cheers!
Bob