Hypothetical Planning In A Real World - Legalities aside (for emergency/disaster utilization only)
Before we go too far down this rabbit hole, and since others who don't understand FCC rules will be reading this in the future, lets cover something really quick:
Amateur radio, GMRS, FRS, MURS, CB radio FCC rules do not change when there is an emergency or disaster. None of the FCC rules permit any different operations when there is an emergency/disaster. The same rules apply as any other time.
Amateur radio operators are restricted to the amateur radio frequencies and power limits under all situations.
GMRS users are restricted to the GMRS frequencies and power limitations.
Same with FRS, MURS, CB, etc.
There are a lot of people that will claim that the FCC rules don't apply when there is either a real or perceived emergency. FCC has made it clear and backed that up with enforcement and hefty fines (plus, getting it plastered all over the internet with names, call signs, etc…)
Just in case someone reads this later and is looking for justification to ignore established FCC rules.
[Tornado, Hurricane, Earthquake, Flood, Forest Fire], is it even possible to have good CLEAR communications with minimal background static/noise with the following parameters?
• (1) 50-watt radio transceiver (unlocked) with battery backup
• (1) Multi-band antenna (height TBD based upon location and terrain)
• Ability to hit existing repeaters within a 50-mile radius
► 2m
► 1.25m
► 70cm
Clear/minimal background noise depends on a lot of variables. Unless you have control of those variables, the answer is "no".
A 50 watt radio, "unlocked or not" isn't going to ensure you'll make 50 miles. Remember, two way radio requires appropriate equipment on both ends. Unless you have control over both ends, everything goes out the window.
Range will depend on the topography around you. 50 watts on any of those 3 bands isn't going to magically pass through mountains, hills or deep into canyons.
In a true disaster/emergency, repeaters are going to depend on power, and how robust it is. Towers collapse, power goes out, poor installation tends to show up when things get stressed. Unless you have control over the repeater and installation, or trust those that do, relying on rando-repeater in an emergency is not a good idea.
Antenna and antenna heigh make a big difference. You'd need to look at what sort of terrain you are dealing with and do your link budget calculations to determine if you even have a path to work with.
For emergencies, I'd be looking at simplex communications to remove all the reliance on "someone else's stuff" in the middle. You'd also need to make sure everyone you want to talk to is setting up their stations with the same level of quality, reliability and proper design if you want this to work.
Remember, GMRS requires proper type accepted equipment under all circumstances, no exceptions.
The rules for GMRS are different than ham, so make sure whatever design you come up with takes all this into account.
GMRS isn't going to be noticeably different than 70cm amateur from a technical standpoint. The frequencies are close enough that the perform pretty much the same. The benefit to GMRS is that it is easier to get a license and easier to get the non-technical people in your family/friends circle involved.
As for frequency range, would a discone antenna be a viable option?
I'll get flamed by some for this, but I'm going to say it anyway:
Discone antennas suck.
The only redeeming value of a discone antenna is that they have a lot of useable bandwidth. They have zero gain compared to a quarter wave. Their radiation pattern is less than ideal.
If you want reliable long range communications, a discone is not a good choice. Properly spec'd band specific antennas with suitable gain/radiation patterns will run circles around a discone. Discones also tend to be a bit fragile if you are looking at those in the hobby realm. Not a good choice for high winds/damage survivability.
While mostly intended for scanners, most of them indicate the ability to also TX on 6m, 2m, 70cm, 33cm, 23cm; and they are omnidirectional. And yes, there are a LOT of hills and forests between my location and many of the repeaters. Unfortunately, most of the areas with repeaters are farther away from center location (see map) so, as indicated, versatility is key - who's listening on which band in what direction and able to respond ...
You can absolutely transmit with them. I have a $3000 Telewave discone antenna on one of my high sites that I use with a remote receiver for testing and as a back up antenna for some VHF and 800MHz repeaters. Yes, it'll work, but it is a poor performer compared to band specific antennas that have gain. It's strictly a wide band receive antenna and there as a backup antenna if one of the dedicated 800 or VHF antennas fail. I'd not install one as a primary antenna for anything other than a wide band receiver. There are much better choices.
With the topography you have around you, getting 50 miles of range is going to be a challenge unless there are some really good repeaters around you that will be there in an emergency.
Might be worth playing around with some of the radio propagation tools that are on line. The good ones will let you put in antenna height/gain/ERP values for both ends of the communications path and take into account local topology to give you a pretty good idea what your coverage will be. There's just too many variables to try and guess at this, and guessing wrong gets expensive really fast.
This whole scenario is a result of the recent tornados that wiped out much of West Kentucky, including Mayfield, where I have family. I was NOT able to raise anyone on 2m or 70cm (no one monitors the 70cm repeater right here in my own county), but WAS able to contact a couple of people over GMRS. Again, maximum versatility is essential in such a disaster.
I've been a ham for decades and have held a GMRS license off and on since the late 1990's.
Neither ham or GMRS is an emergency radio service. Relying on it for emergency communications is not a good idea. There is no requirement that the repeaters be built to withstand bad weather or power outages. It's a real crapshoot. Same with GMRS.
I've tried to use both ham and GMRS in emergencies, and I learned my lesson. There's no requirement that anyone be listening or willing to help unless you have arranged all that ahead of time. In an emergency, most people are going to be looking after their family first, radio will come later. Don't rely on a hobbyist to be a first responder.
If you expect to be in any emergency situation where normal communications will fail (internet, wired telephone, cellular, etc), then hobby radio services are not the solution.
If you want reliable communications in such a situation, there are a couple of reliable options:
-Satellite phone. Expensive, but will put you in immediate communication with others.
-Modern cell phone that has satellite SMS capability. Many of the more recent iPhone and Android phones can send text messages through satellites and will get your message through.
-Satellite based devices like Garmin InReach. These will allow you to hit and SOS button and be put in contact with professionals that will get you the help you need. They also allow you to send messages/e-mails to others.
I understand what you are looking for here. Radio is a nice tool to have. It should not be the only tool you have. Relying on hobby radio services isn't good planning. Even with an unlimited budget, it gets difficult to do with any sort of reliability.
If I had to do this and my only option was amateur radio, I'd probably be looking at HF with an NVIS antenna and making sure I had someone on the other end that would be ready and listening if I needed their help. Other than that, I'd stick with the satellite phone/cell phone/InReach type device. those are the only ones I'd rely on if my life was depending on it.
