my experience with GMRS so far

[dreadlocks]

I'm near Havana and Parker, bout 7m to your NE

 

[BigDaveZJ]

Pretty sure we would be able to make it that work, but I might have to go uphill a little bit. My house is pretty close to the Highline Canal, so it sits a little low in elevation compared to some of the surrounding areas.

 

[Billoftt]

If you use Google Earth, click on the "ruler" on the top tool bar.

When the Ruler Tool pops up, click on the second tab, "Path."

Make sure you check the box that says "Show Elevation Profile"

You can now click two points in Google Earth and it will give you an elevation profile and the distance between two points.

Things to be aware of: This does not account for antenna height nor account for curvature of the earth.

Sent from my SM-J320P using Tapatalk

 

[Billoftt]

You can also go to this website to plot an actual RF coverage map.

Radio Mobile Online

www.ve2dbe.com

Be advised, it is in French and it is metric. However, you can input your antenna gain, antenna location, cable loss, antenna height, ground elevation, frequency, receiving antenna gain and height, etc. and it create an RF map using elevation data for the area.

Sent from my SM-J320P using Tapatalk

 

[dreadlocks]

I actually run a APRS Digi on my roof, so its real easy for me to plot coverage maps..

this is my direct coverage of denver, my height above average terrain is ~161ft w/6.7dbi omni.. now the GMRS coverage outta my vehicle is pretty similar


hit me up w/a time and frequency and I'll try to meet yeh there.

 

[BigDaveZJ]

If you use Google Earth, click on the "ruler" on the top tool bar.

When the Ruler Tool pops up, click on the second tab, "Path."

Make sure you check the box that says "Show Elevation Profile"

You can now click two points in Google Earth and it will give you an elevation profile and the distance between two points.

Things to be aware of: This does not account for antenna height nor account for curvature of the earth.

Sent from my SM-J320P using Tapatalk

I knew there had to be a way to do that, just couldn't put what I was thinking into words to look it up, lol.

 

[BigDaveZJ]

I actually run a APRS Digi on my roof, so its real easy for me to plot coverage maps..

this is my direct coverage of denver, my height above average terrain is ~161ft w/6.7dbi omni.. now the GMRS coverage outta my vehicle is pretty similar
View attachment 531627

hit me up w/a time and frequency and I'll try to meet yeh there.

The yellow house with the red car above it is basically where my office is. Looks like pretty good coverage near my house too. I'll let you know next time I plan on messing with the radios a bit. Interesting how the signal map follows interstate corridors as well.

 

[dreadlocks]

thats where most of the taffic is so thats where I get the most packets naturally..

 

[BigDaveZJ]

Gotcha, when using the ve2dbe maps it seemed to follow terrain more.

 

[Skimaniaz]

Here is another site that displays line of site for different areas.

What is the Maximum Range I can Get?

INTRODUCTION The Maximum Range achievable at any location depends on (1) Curvature of earth (2) The terrain around that location. Terrain plays a very important role as hills & changes in ground level will restrict maximum range. This is due to the fact that propagation of radio waves in...

discussions.flightaware.com

 

[Skimaniaz]

Here is a website that shows GMRS repeaters in case there are any in your area, would drastically extend the range of your communication.

myGMRS.com - Repeater Map

mygmrs.com

 

[BigDaveZJ]

So the picket fencing that I had been getting seems to only happen when one or both people are moving. When they're stationary, no sign of it at all.

Found out the Baofeng HT I got on an Amazon flash sale can also handle GMRS freqs. Not sure how legal that is, but it worked.

I used some of the mapping software posted above to find some spots that should work and really test the distance on these things. Going back up to the mountains this weekend, might try some of them out.

 

[dreadlocks]

you just been testing in town? the picket fencing is from multipath interference, and UHF loves to bounce off all the buildings and flat surfaces here.. which is good for propagation, but bad for multipath interference.. it might get better up in the mountains, the pine trees absorb signals instead of reflecting it so multipath will go away unless your in a canyon.

Legally its a grey area, its not correctly type certified.. but, GMRS bands have zero enforcement, even if they did nobody could tell if your transmitting from a correct device as long as your following all the rules.. I'm of the opinion its okay to break a few eggs to make an omelet, as in.. If nobody is using GMRS, paying for licenses, or advocating its usage.. then we're going to loose it to commercial interests, so use it or loose it > legal certifications.. just hold a license and follow the rules/bandplan and your a better GMRS citizen than 90% of its users.

 

[BigDaveZJ]

Some in town, but noticed most of it on 285 in the mountains. Was very intermittent and hard to pin down an exact cause. My wife was behind me in her JK and I was in the truck pulling the 5th wheel. I'm guessing the 5th wheel being so close to the antenna was not helping things at all.

Yeah there's definitely a lot of GMRS use that's not licensed. Pretty sure the local Ace Hardware is using ch 20 for their in store comms.

 

[DaveInDenver]

Yeah there's definitely a lot of GMRS use that's not licensed. Pretty sure the local Ace Hardware is using ch 20 for their in store comms.

They may be using FRS, which is legal for commercial. GMRS (like amateur radio) can't be used by a business to get around licensing. Channel 20 is a 2 watt FRS shared channel under the new (2017) Part 95 rules.