GMRS Daytime Performance

[Hans13]

Yup, there is no perceivable loss through humidity like fog or even rain at UHF or 800MHz. When you get past about 2GHz rain fade starts to be measurable, at 6GHz rain is a slight concern and at 14GHz and above it’s a big problem. I spent 18yrs working on satellite uplinks and downlinks monitoring 4GHz, 12GHz and 20GHz satellite beacons passing through the atmosphere in clear sky, fog and rain. I’ve never measured even the slightest change from clear sky to dense fog through 12GHz, none. My equipment logged various satellite beacon levels 24/7 and I had many years of data to review.

Now if the OP is seeing day/night changes in a non line of sight system with moisture on foliage that both passes signals through it or foliage on a hillside that is bouncing the non LOS signal to him, then yes you may see day/night or dry/wet changes in signal strengths. That is a real problem. And no ChatGPT was used for this post.

Thank you so much for this very useful reply! Hopefully I don't forget over time but at least it now puts to rest any suspicion that I had regarding the issue. (I am not the OP but was wondering similar.)

 

[oregontreehugger]

That sounds more like someone near you has solar panels that are either creating noise themselves, or a cheap @$$ inverter connected to them that's spewing out trash that wipes out the signal.

Thanks for this helpful tidbit -- running into this here locally and all of a sudden it makes perfect sense.

 

[Talkinggoat]

Thanks for this helpful tidbit -- running into this here locally and all of a sudden it makes perfect sense.

After speaking with some of the other stations, we are sure this is some kind of atmospheric ducting, not interference or the noise floor. There is another station, about 30 miles north, who was hitting a repeater in New Orleans, 104 miles away, at 6am. He confirmed, when the sun came up, he lost contact within 10 minutes. That distance should not happen with GMRS.

The repeater we were hitting, though, was about 50 miles.