We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: Dual Side Band data pips?  (Read 3135 times)

Offline Antennae

  • Hero Member
  • *****
  • Posts: 648
  • CA, USA
    • View Profile
Dual Side Band data pips?
« on: March 11, 2015, 2202 UTC »
1. 9085kHz  (between twin bursts)
2. 3/10/15 20:05utc
3. 5 sec intervals
4.XCVR mode: USB/LSB, DSB?
5.SW Coast USA
6. Mid-day, I saw some pips on the waterfall.  These are short bursts of data.  Sounds like a short burst of consecutive beeps of differing tones.  There are twin bursts that are asymmetrical.  Assuming the mode is DSB, every once in a while the USB burst will be one solid tone while the LSB has none. LSB sounds like lower tones and USB sounds like higher tones.   

Here's a picture:
California Coast
Antenna: random wire

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 2118
    • View Profile
Re: Dual Side Band data pips?
« Reply #1 on: March 11, 2015, 2300 UTC »
I am not near a radio so I can't check right now, but that has the looks of an RTTY signal that is having issues.

The spacing is correct for 850 Hz shift RTTY, and I have seen RTTY signals show similar characteristics when there was intermittent audio or transmitter issues.  I bet if you watch that freq for a while you will see STANAG 4481 FSK or similar, 850 Hz FSK, centered on 9085 kHz.

T!

(edit)  Finally got home after a 20.5 hour day, not counting commute time, and did find an FSK signal on 9085 kHz.  It does look like S4481 FSK, 75 Bd 850 Hz shift, KG-84 encryption.
« Last Edit: March 12, 2015, 0638 UTC by Token »
T!
Mojave Desert, California USA