Hi Alan, thanks for checking in on the net last night, and for your question!
Getting an external antenna up on your roof, or as high as you can, is often the best way to extend the range of your radio, both on receive and transmit. If you can upgrade from a handheld radio (usually 5w output) to a mobile style radio with 20w, 50w or higher output, that will help a lot too, especially when paired with a roof-top antenna.
There are many solutions for how to get a good antenna up high, and they will depend on what mounting options you have available, where/how you can run a cable, how permanent you want it to be, etc.
For the antennas themselves, there are numerous options, including many commercial grade antennas that can cost several 100 dollars. What a bunch of us use, including myself, is Ed Fong's "DBJ-UHF" antenna, which comes as a kit, where you need to supply your own section of PVC pipe (note that you'll need 5 ft of 3/4inch "200 PSI" type pipe which is a bit hard to find, NOT the more common "Schedule 40" PVC pipe). Alternatively you can also use Ed Fong's "DBJ-1" dual-band antenna (VHF & UHF), so long as you get the one tuned for the "commercial" bands which covers the GMRS frequencies (and not the "ham" tuned version). I have the DBJ-UHF mounted on my roof on another piece of PVC that's clamped to a vent pipe on my roof - see the attached photo. It's not the most robust installation, but it has survived on my roof for 6+ years now. I have about 50' of good coax running down to my radio shack in the basement. Let me know if you need pointers to other antenna options, or coax suggestions.
If you want something less permanent, and more portable, you can also consider getting one of Ed Fong's DBJ-2 roll-up J-Pole antennas, which you can easily get up high using a string over a branch or other high spot. Again, for GMRS you'll want the "commercial" version, not the "ham" version.
Ed used to sell directly through EBay, but I'm not seeing his seller ID on there right now, though it looks like a few 3rd parties are selling his gear. I believe you can also get his antennas from some of the big ham radio suppliers, or you can order from him directly - see his website (
https://edsantennas.weebly.com) and find the paragraph that starts with "Ordering Information...".
Let me know if you're interested in higher power mobile radios too, and I can provide some more pointers on that.
Cheers, -Chris WQPD858 / KJ6WEG