# How to predict radio range of a product?

I'm shopping around for a next level radio since all I have at the moment is my Baofeng.
I've been asking around on my repeater club on how to best choose a radio.

The metric I'm most concerned about is range.

But the problem is the articles I read and the fellow hams I ask say the same things:

"Range is dependent on...

• Power (wattage)
• Antennae type / quality
• Environment"

There must be some way I can look at the specs on a radio before buying and say it has more or less range than another radio?

• Serious question: was how the range of communication is effected by the things you mention not subject of your ham exam? Nov 22, 2022 at 7:54
• @MarcusMüller the US tech exam is pretty light on that stuff. There are a couple of questions in the current pool about multipath, one about rain fade for microwave, one about knife-edge, a couple about tropo, one about "the radio horizon is slightly beyond the visual horizon", but it's just assumed that you have all that stuff in context. The actual basics aren't really tested, so depending on your method of studying for the test, you might miss them entirely. Nov 23, 2022 at 0:44
• That's interesting to know! Thank you, @hobbs-KC2G Nov 23, 2022 at 0:47
• I was looking for a metric or formula when I started studying for my Technical but the answer I got from the exam prep was more complicated and unsatisfactory, basically "it depends..." is all I got. Nov 23, 2022 at 6:04
• You might check out signalserver.okiefrog.org for some modeling insights Nov 30, 2022 at 3:08

They use range specs to market VHF/UHF handhelds to people who don't understand radio, but those specs are essentially useless. Half a watt will easily go hundreds of km if there's nothing in the way, as any ham who's played with satellites knows — but 50 watts won't be enough to go 2km if there's a big chunk of mountain in the way.

More power helps a little bit to get through "soft" obstacles, like going room-to-room in a building, or to overcome noise in a city environment. A better receiver helps somewhat to pull in a weak signal or to reject noise on other channels. But neither one is a range multiplier in ordinary situations. Neither one will let you go significantly further over the horizon, or make very much difference in the shadow of an obstacle. They'll help clean up a noisy signal if you're on the fringe of coverage, but they won't push that fringe out very far.

What you really want is five watts, a reasonably efficient antenna, and reasonably well-designed electronics. Which is something that you will get from most radios. You can spend extra to get things like a rugged/weatherproof case, nicer controls/display, better battery life, compatibility with your favorite digital mode, or any number of bells and whistles — but once you've reached that plateau of decency, all handhelds are going to be very nearly the same in terms of how far you can go.

If that doesn't do it for you, then you start thinking "how high can I mount an antenna for a base station?", not "where can I get a better HT?"

• Upvote for acknowledging how the questioner's confusion naturally arises from how consumer radios are so often marketed at least in the USA! Otoh it's reasonable for e.g. an FRS manufacturer to set expectations of approximate range, otoh said manufacturers in practice tend to make rather optimistic claims as if their products were competing with each other on those range "metrics"! Nov 22, 2022 at 20:48
• This is a nice answer as it's explains the impossibility of sticker values in consumer electronics :) Nov 22, 2022 at 23:16
• Thanks for the response! I suppose part of the fun is finding out where your contact is located and seeing how far that location is. I was expecting some answer like "they test all radios in a desert with no obstructions and X radio can reach X km" but even that kind of test would be insufficient since even a few watts will travel the greatest distances. Nov 23, 2022 at 6:10
• @engineer-x well, keep in mind the Earth is round, so you only have to go a few miles in a "perfectly flat" area before the thing that gets in the way is the ground. Further than that implies that at least one end is elevated — mountain to mountain, mountain to valley, tower to ground, ground to aircraft, ground to space, etc. :) Nov 29, 2022 at 15:01

There isn't a way. Range is a property of your transmit power (wattage), how much of that goes in the direction of who you're talking to (which is an effect of your antenna), how much of that reaches your communication partner (what you call environment) and how sensitive your communication partner's receiver is (which is mostly an effect of how low in noise that receiver is). The same chain of effects appears in the other direction, in case you want to receive the reply of that communication partner.

As you can see, some (most) of these factors are out of control of your radio, so your radio can't have a sticker that says "reaches 200km" because it simply can't control that.

You can only select a radio by the properties of the communication links that it can actually contribute to. And those are transmit power, receiver noise figure, and antenna efficiency. (Where for a handheld a highly directive antenna makes little sense, since you would need to accurately point the antenna if it's very good at focusing energy in one direction, which is very undesirable for mobile devices, since you can't even know in which direction to point)

• Upvote for explaining why the things range is dependent on can't be reduced to a "sticker value" in kilometers or miles. Nov 22, 2022 at 20:55
• Thanks for the response! Like I said in the other comment: I suppose part of the fun of ham radio is finding contacts and seeing how far they are. I was hoping for some straight forward math formula but that's just not how this works with all the different parts you could mix and match. Nov 23, 2022 at 6:14
• Well you do get a relatively straightforward formula, but it has the mentioned unknowns... Nov 23, 2022 at 6:45

RE: "There must be some way I can look at the specs on a radio before buying and say it has more or less range than another radio?"

Unfortunately, while this question is clear and simple, its accurate answer is not simple to produce — because of external factors that are not included in the specs of that radio.

If the analyst/user knows those external factors, then a good estimate of the point-point range of that radio may be calculated using computer software. Below is an example of the output presentation generated by such software, when the field it generates at the far end of the path can be used along with the gain of the receive antenna system and receiver sensitivity, to learn if the receiver output may be useful for the purpose of the link.