Batboard

Is anyone aware of any systems that transmit a 2850Hz pilot tone? I have a a 800Mhz Quantar in the Bronx that I was able catch interference coming in on the RX today, and it sounds like a continuous 2850Hz audible tone. It lasted for around 15 min then cleared itself. I have remote access to a computer that sits at the tower site that is loaded with RSS and connected to the serial port of the Quantar. Checking the RSSI indicated that a transmitter somewhere is continuosly keyed, so I'm fairly cofident it is an RF source. I also have a cable that connects the front handset jack audio of the Quantar to the line in of the computer's sound card, so I was able to record and download the interference audio.

Any ideas appreciated.

Thanks!!!!!
Zaputil

Grasping at straws here, but maybe there's still an old GE MARC-V system on the air?

I seem to recall they transmitted a ~3 kHz pilot tone on the repeater output; don't know if that was present on the input coming from the mobile as well.

--mws / kf4lhp

Isn't OpenSky being built out in NYC right now? Is it possible that you are receiving interference from the old Metro system being switched to OpenSky?

There wouldn't be a 2850hz tone...

Opensky's system has the same charactristic as cell data. You should be able to hear the PA Opensky from Beach Lake around the 866.x area. I believe there are 3-4 different channels running continously in Wayne County that you can pick up (from at least here).

BTW, check RR.com for thost NPS channels that I finally tracked down.

Fair enough. I hadn't heard the OpenSky signal before so I wouldn't have known... just a best guess. I ended up getting NPS frequencies from them directly. Works very well on the new scanner at work.

I'll give it a try when I get home later and see what I can hear. Unfortunately I am in enough of valley that I may not get it there.

UPDATE:

The interference looks like it was comming from a mobile stuck on transmit. The tone was just a weird byproduct at that tower. Thanks for your comments!