[GMRS: GPS Location and Texting...]

The repeater on 625 was quiet. I called out to the input frequency +5mhz with the tones listed in the page, and with in 60 seconds someone started jamming the Wilson and Harvard repeaters with what sounds like a digital trunking system, or just constant keydowns... Is it correct that digital modes are NOT allowed on the GMRS frequencies except for short bursts for text and location information?

[GMRS: GPS Location and Texting...]

 I am brand new to GMRS. It would be interesting if we could coordinate and try and see if we can make contact on one of those repeaters. I set my radio up for the Wilson repeater and am going to try it out shortly and see if I can get anyone on it. 

 

Regarding the SDR, yeah, I thought perhaps it could have been harmonic interference, I didn't spend a lot of time playing with it, but the digital signals were mostly on 462.7250

 

I do occasionally here a repeater(?) sending code on 462.625, but I can't copy code (yet) so don't know what the sign is. 

 

73

  

You're probably seeing the POCSAG transmitters on 462.800 MHz appear on 462.600 MHz and 462.625 MHz. Those are two repeaters (Wilson and Harvard, respectively) getting jammed. It's been going on for several months and is heavily impacting usability of the VNC600 repeater in Ventura County. It's not 24/7, but goes for several hours at a time. Seems to be the result of a squabble between Dennis Doty and Kevin Bondy.

 

Someone is running MOTOTRBO on 462.550 MHz, but it's rarely active. I think it comes from Saddle Peak, but it's so infrequent I can't do any research on that.

 

Aside from those, I'd expect a SDR in Los Angeles to get some nasty front-end overload or intermodulation products. SDRs do not have particularly robust front-ends, and some compromise between sensitivity and selectivity is needed to find a proper LNA gain setting. None of those signals I mentioned here don't really have anything to do with this thread's topic, so those should be discussed in a different thread.

[GMRS: GPS Location and Texting...]

In the Los Angeles area the only thing I have been able to hear are constant digital signals. I am not sure if it is someone jamming repeaters or something else.

 

When I monitor with my SDR, the waterfall shows the signals occur on several of the channels simultaneously. Anyone else experience this?