Hey all,
I found a control channel-like signal recently that didn't match any digital modes I'm familiar with in the Fed Band on 170.0625 MHz, and didn't decode on any scanner. The signal is believed to be on Mt Tam in the San Francisco Bay Area. There's also a P25 control channel for a new federal P25 system at the same site also in the 170-174 MHz range, so I'm starting to wonder if the two are related.
Here's an audio sample of the unknown signal:
I've done a little reading on P25 system coverage acceptance testing methods and the signal strength and BER measurements that are required. Does the above audio sample sound like any system coverage test patterns you guys are familiar with, like for example the O.153/V.52, 1011 Hz (though I imagine the latter would decode on a scanner), etc?
I've checked some of the usual suspect digital modes audio sample websites like the sigidwiki, but haven't found anything matching the sample above. Nobody seems to have audio samples of P25 repeater test patterns however, so I figured I'd run it by the experts.
Thanks for your time!
I found a control channel-like signal recently that didn't match any digital modes I'm familiar with in the Fed Band on 170.0625 MHz, and didn't decode on any scanner. The signal is believed to be on Mt Tam in the San Francisco Bay Area. There's also a P25 control channel for a new federal P25 system at the same site also in the 170-174 MHz range, so I'm starting to wonder if the two are related.
Here's an audio sample of the unknown signal:
I've done a little reading on P25 system coverage acceptance testing methods and the signal strength and BER measurements that are required. Does the above audio sample sound like any system coverage test patterns you guys are familiar with, like for example the O.153/V.52, 1011 Hz (though I imagine the latter would decode on a scanner), etc?
I've checked some of the usual suspect digital modes audio sample websites like the sigidwiki, but haven't found anything matching the sample above. Nobody seems to have audio samples of P25 repeater test patterns however, so I figured I'd run it by the experts.
Thanks for your time!
