Writer seeks information for radio set-up

[EdNerd]

I am doing research for a novel and would like information on a radio set-up that would work for the situation I'm thinking of. Yeah - I could just make something up ... but then I'd lose any reader like you who would throw a BS card and walk away. Besides, I might want something like this myself! :8>)

My setting is the southwest Arizona desert, down by the Colorado River basin. Large flat areas, some hills up to 1500-2000 feet. (If you're familiar with the area, think Yuma to Quartzsite and the Kofa Wildlife Refuge.) Not a lot of vegetation - certainly not forest; occasional mesquite or palo verde trees that might be 20 feet tall, and maybe some saguaro cactus that high too. I'm imagining a severe weather situation, so thick cloud cover and electricity is out.

Let's say I have a person up in the hills 60 miles from town, his truck breaks down, and he needs to walk back home. Is there any possible way he could communicate via handheld back to family in town? What about a truck-mounted mobile radio that he could disconnect and take with him? I can see throwing an antenna wire up over a tree, if he's got a radio that would accept an external antenna. Would GMRS work, or would it have to be Ham? If power is out, the repeaters are too - yes?? What about satellite repeaters?

Like I said, I could just make something up. But I'd rather not. If anyone is willing to lend a drop-kick in the right direction, I'd really appreciate it!

Thanks!
Ed

 

[AK9R]

Many mountaintop repeaters have some form of off-grid power. Solar, wind, batteries, backup generator.

 

[EdNerd]

So ... pretty much any decent radio, especially if I can connect an external antenna??

 

[jonwienke]

60 miles is a bit of a stretch for a handheld to work reliably. But 30 miles is pretty doable, given a reasonably clear signal path to a repeater with a good antenna.

I was listening to a ham net last night where a guy on a handheld on the Appalachian Trail just north of the Maryland-Pennsylvania border was able to check in to the wb8yzv repeater at the VA hospital in Martinsburg WV. He had some noticeable background static, but was making the 33-mile trip just fine, thanks to a clear line of sight.

Find a high hill about halfway between where your character breaks down and the help he needs, put your notional repeater there, and it could work as a ham or GMRS setup. If your guy has a mobile radio in his vehicle, you can plausibly add another 10-20 miles to that leg of the trip.

Also, several brands of handheld and mobile radios have built-in GPS, and can transmit APRS location packets either on demand, or programmed intervals. Transmitting a ping every 30 minutes or so while on the move would make finding your guy a lot easier. If there was a good reason to move rather than hole up and wait for help, that is...

 

[RFI-EMI-GUY]

The absolutely simplest repeater that could work would be a solar powered simplex parrot repeater. Argent Data Systems sells the controller. Connected to a mid powered mobile radio and good sized solar battery system would give balanced mobile coverage. it would be a small investment, something a prepper might surreptitiously install on someone else's mountaintop .

 

[EdNerd]

The absolutely simplest repeater that could work would be a solar powered simplex parrot repeater. Argent Data Systems sells the controller. Connected to a mid powered mobile radio and good sized solar battery system would give balanced mobile coverage. it would be a small investment, something a prepper might surreptitiously install on someone else's mountaintop .

Ahhhh!! Now that sounds like a little something I can use! :8>)

 

[EdNerd]

Do most GMRS radios allow you to unscrew the antenna and connect to an external antenna? Would just a wire tossed over a tree (like I saw in one video) work okay? Would it need to be a certain length, or dipole, depending on your frequency band?

 

[littona]

If dude is an back-country adventurer... he might carry his own sat phone.

 

[RFI-EMI-GUY]

Examples:

Low power "ammo can" UHF GMRS repeater with ADS SR-1

Same controller with 10 watt VHF Ham mobile radio.

ADS-SR1 Simplex Repeater, Argent Data Systems

A simplex repeater can be solar powered with a small solar panel andl battery if the average daily use is low.

 

[paulears]

Sat phone would be sim0lest and most believable - but in Die Hard they have magic radios - secret and private and public, and they can interrupt each other too - nobody worried about that. Even better was Skippy the Bush kangaroo when I was growing up and I can even remember the callsign XMY557 A for Apple calling XMY557 B for Bear, and with the huge telescopic aerials on 11m (iso) they worked in the Australian outback really well. To be honest, if you adjust the script to make it real, it will spoil it. everyone knows walkie-talkies just work flawlessly. It's kind of movie lore - I'd not worry about the few radio anoraks picking holes.

 

[RFI-EMI-GUY]

For a manpack portable radio. I like this concept. It could be easily duplicated for any small UHF mobile radios like the Kenwood TK-840-1

Leixen VV-898P and VV-898SP Backpack Radio video

This video introduces the Leixen VV-898P and VV-898SP Mobile Backpack Radios and explains how they can be used for a variety of mobile activities and applications.

www.buytwowayradios.com

 

[RFI-EMI-GUY]

Sat phone would be sim0lest and most believable - but in Die Hard they have magic radios - secret and private and public, and they can interrupt each other too - nobody worried about that. Even better was Skippy the Bush kangaroo when I was growing up and I can even remember the callsign XMY557 A for Apple calling XMY557 B for Bear, and with the huge telescopic aerials on 11m (iso) they worked in the Australian outback really well. To be honest, if you adjust the script to make it real, it will spoil it. everyone knows walkie-talkies just work flawlessly. It's kind of movie lore - I'd not worry about the few radio anoraks picking holes.

Tom Clancy's novel: Clear and Present Danger, described the military UHF Fleetsatcom network pretty accurately. Clancy was known to provide a lot of technical details. I am one of those who rolls my eyes in action movies like DieHard when the actors use radios to communicate in impossible ways. There is a space TV show where they are traveling to Mars yet have real time cellular type communications.

If the SHTF in a big way, the commercial satellite constellations like Iridium will be overloaded and unusable. Also the ground stations may eventually lose power rendering the constellations useless. The military UHF satellites will probably be more resilient as they are a simple bent pipe with simpler ground control requirements. In fact, Brazilian truckers have been notoriously pirating air time on those satellites for decades using hacked ham radios. It would not be hard for the subject of a novel to construct his own mobile and ground station and access the mil sats for free.

However, the possibility of getting caught is pretty great and the penalties severe. There is a German ham who has been accessing the mil sats using a cheap Russian commercial portable radio. I am surprised he has not been caught as he posts this on youtube of all places.

 

[RFI-EMI-GUY]

If dude is an back-country adventurer... he might carry his own sat phone.

But depending on the scenario, the satellites may be unusable. But then if it were set in 1970, he could hike out to the highway and use a payphone. Or if he had a linemans phone, climb a nearby pole and tap in.

 

[jonwienke]

To be honest, if you adjust the script to make it real, it will spoil it. everyone knows walkie-talkies just work flawlessly. It's kind of movie lore - I'd not worry about the few radio anoraks picking holes.

I strongly disagree. Magically making things work when they have no plausible way to do so, just because plot needs them to, and vice versa, is just hokey, lazy writing. Taking the time to research things to get the details right makes crafting the plot a bit more challenging, but the finished prodict always benefits by doing so. It's the difference between cheap dreck that readers don't bother to finish because the premises and action are too implausible to keep them engaged, and something that engages the reader completely because they believe it.

 

[WB9YBM]

Let's say I have a person up in the hills 60 miles from town, his truck breaks down, and he needs to walk back home. Is there any possible way he could communicate via handheld back to family in town? What about a truck-mounted mobile radio that he could disconnect and take with him?

Police squad cars use what they call a "mobile extender" to allow officers (when they leave their squad car) to talk to dispatch. I suppose if something like that were available on the surplus market (when older units get updated) would be one approach; alternatively a ham radio op could put together a home-made approach...

 

[vagrant]

There are several options:
1. GMRS, amateur and maybe MURS (Relatively inexpensive)
2. Handheld using Iridium satellite (Not inexpensive)
3. Garmin InReach device (Relatively inexpensive)


GMRS, MURS and amateur
Line of sight at 1500' is around 55 miles
Line of sight at 2000' is around 63 miles

If you add the height of an antenna back at the house at 30' above ground level it will add about 8 miles. Communication via simplex for your 60 mile range is reasonable using a handheld and home station. I would recommend your character use GMRS as a handled can provide 5 watts and a mobile up to 50 watts. This makes it quite plausible without the need of a repeater...but your character would need to climb to 1500 or 2000 feet. (MURS on lower frequency VHF may work, but both stations are limited to 2W maximum and no repeater option with MURS. That may be too much of a stretch at 60 miles if terrain and or buildings are in the way. Much depends on the elevation of the house and what might be in the way.)

The radio your character could use is an older Motorola XTS5000 UHF handheld radio. During normal use in the car they slide it into an Motorola XTVA, which basically holds the radio, provides power and connects it to an external antenna on the vehicle. A push of a button and it ejects the radio fully charged and ready to go using the regular smaller antenna already attached to the radio. (I use this setup and it works.) Maybe they normally use a repeater and it is offline with the power outage. These repeaters are owned by you and me. GMRS repeaters are not the same as a public safety repeater system. I'm not saying it could not have backup power, but...I would not count on it.

Handheld Satellite Radio
Another option is satellite using an Icom IC-SAT100. These need a satellite service subscription. These work well in an open area. Still, the radio at the house would need to be outdoors, or use an Iridium antenna on top of the roof of the house or vehicle with a cable attached to the radio. (I used this setup and it works.) This allows Push To Talk communication, or send/receive text messages using the same model radio on each end.

Garmin InReach
There are currently three device options. I use the InReach SE+ and it requires a subscription. Using this device your character could send and receive regular text messages via satellite and it can provide their exact location. A person could use an app on their phone with these devices, or there is an optional button that can be pressed that sends emergency services to your location. Depending on the subscription option, it will send tracking information and someone could monitor the person via a webpage login. As this uses satellite, the user needs to be out in the open with a view of the sky.

 

[hill]

A wire antenna more than likely is used on HF and not on GMRS.

Do most GMRS radios allow you to unscrew the antenna and connect to an external antenna? Would just a wire tossed over a tree (like I saw in one video) work okay? Would it need to be a certain length, or dipole, depending on your frequency band?

 

[RFI-EMI-GUY]

I am doing research for a novel and would like information on a radio set-up that would work for the situation I'm thinking of. Yeah - I could just make something up ... but then I'd lose any reader like you who would throw a BS card and walk away. Besides, I might want something like this myself! :8>)

My setting is the southwest Arizona desert, down by the Colorado River basin. Large flat areas, some hills up to 1500-2000 feet. (If you're familiar with the area, think Yuma to Quartzsite and the Kofa Wildlife Refuge.) Not a lot of vegetation - certainly not forest; occasional mesquite or palo verde trees that might be 20 feet tall, and maybe some saguaro cactus that high too. I'm imagining a severe weather situation, so thick cloud cover and electricity is out.

Let's say I have a person up in the hills 60 miles from town, his truck breaks down, and he needs to walk back home. Is there any possible way he could communicate via handheld back to family in town? What about a truck-mounted mobile radio that he could disconnect and take with him? I can see throwing an antenna wire up over a tree, if he's got a radio that would accept an external antenna. Would GMRS work, or would it have to be Ham? If power is out, the repeaters are too - yes?? What about satellite repeaters?

Like I said, I could just make something up. But I'd rather not. If anyone is willing to lend a drop-kick in the right direction, I'd really appreciate it!

Thanks!
Ed

Pick the hypothetical location described above Location A. Then pick the hypothetical location of his home base in town to be Location C. Go to google earth and search for a mountaintop that is midpoint between A and C. Call this Location B. A repeater of some sort will be required. You can use Google Earth to visualize the path. You really need a line of sight without terrain blockage. Can A see B? Can B see C? If yes for both you have a path.

As far as portable radios depending upon model, they can have optionally a 5/8 wave antenna about 15 inches at GMRS. That is a practical limit. A mobile can have a 5/8 over 5/8 antenna, ~ 32 inches. Best to have a 50 watt mobile, but a 5 watt portable and a climb up the rocks or a tree can work in a pinch. Terrain height is everything.

 

[jonwienke]

Do most GMRS radios allow you to unscrew the antenna and connect to an external antenna? Would just a wire tossed over a tree (like I saw in one video) work okay? Would it need to be a certain length, or dipole, depending on your frequency band?

Antenna length is dictated by frequency. Feedline length is not. There are roll-up j-pole antennas made out of twin lead that have a length of coax attached. Tie a rock to the end of a length of string, the other end to the top of the j-pole, and throw the rock over a tree limb, and you have an elevated antenna in a wooded area. In a desert, all you need to do is climb the nearest hill or ridge to get decent range.

But none of that is necessary if the vehicle breaks down in the middle of a large plain or on a hilltop. A mobile radio in the vehicle will have more transmit power and a better antenna, especially if it's in the middle of the roof. All else equal, the vehicle radio will have better odds of making contact than a handheld.

 

[W0JOG]

I am doing research for a novel and would like information on a radio set-up that would work for the situation I'm thinking of. Yeah - I could just make something up ... but then I'd lose any reader like you who would throw a BS card and walk away. Besides, I might want something like this myself! :8>)

My setting is the southwest Arizona desert, down by the Colorado River basin. Large flat areas, some hills up to 1500-2000 feet. (If you're familiar with the area, think Yuma to Quartzsite and the Kofa Wildlife Refuge.) Not a lot of vegetation - certainly not forest; occasional mesquite or palo verde trees that might be 20 feet tall, and maybe some saguaro cactus that high too. I'm imagining a severe weather situation, so thick cloud cover and electricity is out.

Let's say I have a person up in the hills 60 miles from town, his truck breaks down, and he needs to walk back home. Is there any possible way he could communicate via handheld back to family in town? What about a truck-mounted mobile radio that he could disconnect and take with him? I can see throwing an antenna wire up over a tree, if he's got a radio that would accept an external antenna. Would GMRS work, or would it have to be Ham? If power is out, the repeaters are too - yes?? What about satellite repeaters?

Like I said, I could just make something up. But I'd rather not. If anyone is willing to lend a drop-kick in the right direction, I'd really appreciate it!

Thanks!
Ed

A ham with experience would add drama and innovation to your story by reverting to Morse Code and simplicity of the using the mic switch to communicate a QRRR message that was picked up by another "old" ham. As a writer myself, I could manufacture a lot of ways to go from there that might make good reading to real readers. Good luck!