DMR Interference on 435.350

I suppose one of the PhD candidates on staff could be pulled away from other duties in the SOC or next generation labs.

 

I scheduled a bunch of the XW-2F passes for satnogs observations over the next 48 hours (actually, I scheduled ALL of them - worldwide, by accident. Had to manually delete over a hundred observations in non-north american locations - now I know... but I digress).

Should be interesting to see if you can even see the DMR on the passband, at least.

 

The UK uses the listed frequencies.

I say track the signal. You can be found.

Do not report fake news.

 

They're coming to take me away. HA HA

The precision tracking we use in the guidance computer can point point a tripod battlestation within 1 meter.

 

War Games and Dr. Demento references in the same topic..... Hmmm....

Other thing that make me say "hmmm" is how does a DMR hotspot with an antenna the size of my..... Umm... finger get into a LEO satellite?

Seems like something with a little more oomph would be needed.

The XW-2f spectrum monitoring is a good idea.

 

I've worked many a satellite reliably with under 10mw. Some of us have gotten into satellites using a whip indoors! (Don't try this at home, kids.)

The MMDVM hotspot I use at home has a surface mounted ceramic resonator for an antenna and I can use it around a mile from the house. It's supposedly 10mw but I've never tested it.

 

It's usually the radio on the other end of the link, or a hotspot tied to a bigger transceiver that is the QRM source.

 

Ok. Sure that makes sense. Thanks. Forgot about the other half of the equation.

 

Another issue is a lot of these hotspots are coming with the frequencies set as default in the 437-400 range. My dv4mini was set up on 438 when i got it. When I first started with DMR I went to a presentation at a local club (not one I am in) and they had like 4 or 5 hotspots set up showing. Anyway they were all set up in the 438 range. When I asked about satelite interference I was told, Don't worry they only put out 10mw. Well now here we are.

 

Back in the early 90s when AO-27 was brand new, we monitored a QSO between two hams in upstate NY using HTs who didn't realize they were in the satellite-only subband, and there was a guy in Canada who regularly got in using less than 5W (unsure what he had for antennas). So this is (sadly) nothing new.