Unidentified Signal on 189.925MHz with Pictures and Recording

I recently purchased a cheapo broadband LNA from ebay (which I’ll review at a later date) and was today scanning around on my RTLSDR via SDRSharp using various antenna combos with and without the LNA connected when I came across an unidentified signal I’ve not seen or heard before. Allowing for inaccuracies the frequency was approximately 189.925MHz.

It’s a Mystery Signal!

Firstly I ran some decoding software I had installed to see if I got any hits (DSD+, Unitrunk, TrunkView, PDW etc) but nothing seemed to decode the signal. My next port of call was SigIDWiki.com to see if I could identify the signal there (visually or audibly) but I could find nothing that matched. So as of this moment in time I have absolutely no idea what it is. I’m going to pass the frequency on to a friend (who is reasonably local) to monitor to see if they also pick up the signal to make sure it’s not something immediately local to me causing it.

Below is an image of the waterfall I took from SDRSharp.

Unknown signal on 189.925 MHz
Unknown signal on 189.925 MHz

This is an audio recording of the signal which is around 25 – 30KHz wide.

Finally this is a baseband recording taken of the signal. I’ve had to use drop box on this occasion to share the file because it’s too large to upload directly to my site at the moment so I apologise for any inconvenience.

It would be interesting to know what this is and if it’s possible to decode it.

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