overland

Two-way radio comms -- GMRS and amateur (ham)

Brian.Whitaker

Trail Grom
Joined
Mar 28, 2022
Messages
11
OTG folks -- Although I'm just getting into overlanding and appreciate the info shared here, I am an experienced radio operator and support EmComm for my community. As I didn't see many references to radio comms on the site so far, I figured I'd start a thread and try to strike up some discussion on this and offer help where I can.

I'm planning a trip to the Lost Coast here in a couple of weeks, and here's the way I'm looking to use radios:

() Right now, we are the only vehicle, so radio comms will be to anyone monitoring in the area and less likely vehicle-to-vehicle in a group.

() I've had a GlobalStar sat phone which I've never found to work reliably; I gave that up for sat messaging service on my Garmin GPS66i. I'll be futzing with that thing a lot ahead of the trip. It sends messages to mobile numbers, which only then can be replied to. I'll be sending out a few messages to friends here before I head out to establish that line of comms.

() I'll be looking for a GMRS repeater in the area, and will map it's coverage in a site mapping tool I pay for. I figure if there's a repeater in the area, that's the best channel to be monitoring and use, even if only for simplex.

() I'll be looking for an amateur repeater in the area, again trying to anticipate coverage. I'll favor 2meter b/c of terrain and better chances of finding someone on. I'll also monitor 2meter FM simplex calling frequency (146.520MHz).

() My rig is a Yaesu FT8900, which I've mod'd for GMRS operation. Antennas are a quad-band (10m, 6m, 2m, 70cm) and a dual-band (2m, 70cm). Both are broad enough band at 70cm to do OK for GMRS. 70cm is at about 440MHz... GMRS simplex and repeater outputs are near 462.500MHz, and the repeater inputs are at 467.500MHz.

() Because it might be fun, I might also look into the possibility of packet operations. Hams can use packet BBSs and also nodes on a network called Winlink to exchange messages with the internet. This is something you'd do from camp, and not while driving, of course. Packet is generally on VHF.

() Lastly, I operate HF voice and data modes as well. From camp, I'll likely set up to be able to operate on 40 and 80 meter bands in the evening. Hams can send Winlink messages over hundreds of miles to a relay station with internet access to get messages to/from the internet.

There's a lot to do and experiment with here with radios, and being mobile and camping with radio is a heck of a lot of fun! I'd encourage anyone interested to start with a GMRS license -- fee only, no testing, good for the whole family! That's like the radio gateway drug to amateur radio :) Feel free to contact me here or offline about any of this. I'll try to make it a point to include some feedback about radio comms from my trip.

Brian.
AG6WR, WQSK720
<amateurcall>@arrl.net
 

offroadkid

Trail Grom
Joined
Mar 28, 2022
Messages
4
Thanks for all the information! Most of my friends have their HAM License but I don't have mine. I recently discovered GMRS on the internets and have been wondering if I just do that instead! Now I need to get serious and learn and decide.

Lost Coast is neat, we last went in 1997! I want to go back but I have heard stories from friends that it is pretty crazy now with the locals up there? I hope this isn't the way it will be now.
 

Brian.Whitaker

Trail Grom
Joined
Mar 28, 2022
Messages
11
I created a coverage map from the best (maybe only) amateur repeater with any coverage of the area. Looks like we could probably hit that repeater from up on a ridge, but hopeless, obviously, if on the western slope of any ridge. This suggests a sponsored site to host a GMRS repeater could probably help a lot of adventurers.

I haven't read about how to best stay friendly with the locals.

Totally unrelated, we might have some interest in a thread on responsible firearms ownership and treatment on overlanding trips.

Brian.

N6VA coverage.png
 

offroadkid

Trail Grom
Joined
Mar 28, 2022
Messages
4
Would you suggest I will be okay with just a GMRS License, or is HAM a better decision? I'm not so good at taking tests!
 

Brian.Whitaker

Trail Grom
Joined
Mar 28, 2022
Messages
11
@offroadkid — GMRS license and decent equipment will solve many problems for overlanding and EmComm. 50W, repeaters, big antennas… amateur allows tremendous options, depending on your license class (experience, study). Start with a license, a Midland MXT400 or similar quality mobile rig, mag-top antenna and experiment with that.

One problem that amateur can solve is non-line-of-sight comms without a repeater. Advanced folks will do as the military does and bend a long whip over the truck and operate at low frequencies… low enough to bounce straight off the ionosphere and “rain” back down over an area of hundreds of miles. Although I love the idea, not much good if I’m the only one in the convoy :)

Brian.
 

Mutt Wagon

Weekend Warrior
Joined
May 27, 2021
Messages
48
I’ve got both HAM and GMRS setups. Most of the folks I’ve been in trips with do have HAM, and a lot run the cheap handheld units. I ran a cheap hand held connected to a mag mount antenna for years and it work as well as anything. I got the GMRS recently as some folk prefer that route for a reason or another. Both work well in a group, but HAM does have more bells and whistles, like APRS. I’ve not bounced signals yet, and my dual band doesn’t have low enough frequencies to do so. @Brian.Whitaker does that GMRS mod work on dual band yeasu radios? And does it require a separate antenna?
 

Brian.Whitaker

Trail Grom
Joined
Mar 28, 2022
Messages
11
() bouncing signals off ionosphere for close contacts means frequencies like 2, 4 or 7MHz, and horizontal antennas longer than a trucker’s CB antenna if possible. In addition, you can’t run FM down there (well, blasphemous to do it); need SSB.

() APRS is very convenient in a group and in EmComm. Works best when there are monitoring stations to relay via air or internet.

() For Fm voice, GMRS is very much like 70cm band amateur. Amateur allows you to run 2meter (145MHz) which propagates better in terrain. Antennas and power you’d run in a truck are similar though.

() So far, I’ve been able to mod every radio I have, and most are dual band Yaesus (FT60, FT8800, FT8900, iCom705).

() Antenna bandwidth at 440-480MHz needs to be looked at to decide if you can run 70cm ham and GMRS on the same antenna. Little rubber duck: no. 19” mag mount? Probably. Diamond or Comet build a mobile antenna specifically for that application.

() Glad to hear your crew does ok with cheap radios. I’ve had problems and frustration, and I’m an RF engineer by trade so appreciate the quality and am fortunate to be able to afford it.

Brian
 

Mutt Wagon

Weekend Warrior
Joined
May 27, 2021
Messages
48
The cheap hand held leave a lot to be desired, but they are an entry level price point most can do. I ran mine on a mag mount till the glue in the mount gave out. I switch to a trunk mount diamond and then a FT300DR a year later. I have a 15w Midland GMRS radio and separate antenna spec’d for GMRS. I’ll have to look up the mod for the Yeasu, as it sounds intriguing. Thanks For the info!
 
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