SteveShannon

I haven’t seen any reports on this forum. I think you’ll have to try it and let us know what you think. Keep in mind that most GMRS antennas are vertically polarized.

Absolutely. Sometimes I miss the most obvious things.

Nope, unfortunately not. The others are also programmed into my radio. The frequencies are all different. That’s the closest of the linked repeaters (since Butte/Red Mountain is down). The one in Butte is off the air until we get the electrical service replaced.

Agreed. I didn’t know “they” said it didn’t, but UHF (and higher frequencies) reflects very well from some materials, just not from the ionosphere. Passive reflectors are common for microwaves. The mountains in my area are fairly rich in minerals. Butte’s nickname for a century has been “The Richest Hill on Earth” due to the mining activity around here. Whether those minerals contribute to the possibility of UHF reflecting I don’t know, but they don’t seem to retard reflections.

I wouldn’t think so; there’s no knife edge type of topography between me and my friend’s house. But there are definitely features that would support reflections.

WebSDR might provide some of what you’re interested in if I understand you correctly. Unfortunately, in the United States I don’t see any VHF and UHF SDRs, but apparently they’re big in Russia . You might want to set up your own SDR using ka9q and an rtlSDR and a computer: http://www.sdrutah.org/info/using_ka9q_radio_with_the_rtlsdr.html

Thanks again for doing this. This first picture is looking in the direction of the Boulder Hill Repeater. The second picture is of the cabin. The cabin is in what’s referred to as The Boulder Batholith. The ground is full of these granite boulders. I like it.

Thanks for your work. Just one small correction: This is on 440 MHz

Here’s the best I can do, sorry. I’ve never been there. http://www.macpassradio.com/mprg/boulder/

I think @WSGI548 is probably right about the signal reflecting from something. There’s an old iron transmission line going through the park. There’s are a couple cell towers. There’s granite mountains on either side of the park. Radio is magic sometimes. Even more astonishing is the fact that I can use the Boulder Hill DMR 70 cm repeater from my cabin. It’s much further north and with more mountains between it and me. I don’t have coordinates, but I can give you the website and you could approximate the location. I haven’t tried, but I suspect that these programs will predict failure.

Absolutely, because it gets the signal above the terrain.

Thanks! He was probably running at 20 watts, but I doubt that makes a huge difference.

Unfortunately, it doesn’t work like that. The range is not proportional to the power. The signal strength certainly improves with increased power, but terrain is usually the limiting factor at UHF, regardless of power. More power doesn’t make the signal follow the curvature of the earth and UHF stinks at skipping off the ionosphere. Once in a while the troposphere lends a hand though.

I think it probably is.

My radio was a typical dual band handheld, 5 watts. Here’s the coordinates of my cabin. It won’t exactly match the coordinates from before; I just picked them on the map approximately. 46.13057° N, 112.39271° W

I know it reaches. My point was simply that if you looked at nothing other that the line of sight tool in scadacore you wouldn’t expect to be able to communicate on either VHF or UHF.

Mine is. His is probably 7 meters above ground, but if you look at the topography there are probably 10 kilometers of intervening granite that is as much as 500 feet higher than the “line of sight“ between my cabin and his house.

It really depends on circumstances. In ordinary circumstances you are exactly right. Hams talk to the ISS using 5 watts. It’s 200+ miles away, but there’s nothing but air, clouds, and pollution between us.

I don’t understand the intent of your post.

That’s about the max for simplex between two hand held radios in an urban area. Some people only get half of a mile. To get further than that you need a situation that removes obstacles between your two radios. Being on opposite sides of a valley with tall antennas would help, but if you’re both at street level it’s limited, even though some manufacturers proudly plaster “up to 35 miles” on the package.

You’re probably just desensing the second radio. Desense happens when you place two radios too close to each other and transmit on one. The receiver on the other one gets overwhelmed, even though it’s on a different channel and as a result it cannot receive the weaker repeater transmission. Move it fifty or a hundred feet away and try asking for a repeater check.

Video record the front of your radio while it’s doing this and post it for us to see. In one case a person had dual watch turned on and had channel B set to the channel that was actually transmitting while he was wondering what was going on with channel A.

No, if you make it to the toilet it’s diarrhea; if you don’t it’s the shits.

Well, that stinks.