# Can I communicate 40 miles away with a base setup

I’m wanting to get a ham radio license and a good base station set up in my home. The reasoning is to communicate to my family approximately 40 miles away from me in case of a emergency or SHTF scenario. What would we both have to have to accomplish this? I am really inexperienced in this field of ham but since this is the reason me and my family both want a setup for both our houses it’s important I know what for us to purchase. Thanks so much! -Casey

• What level license do you plan to get? Any licensed hams at the other end? What band do you expect to use? BTW, Welcome to Amateur Radio Stack Exchange; please take the tour and read through the FAQ to learn more about how Stack Exchange sites work. – Zeiss Ikon Jun 10 at 11:13
• Other considerations are how tall of a tower you can erect both on your end and the other and what sort of antenna restrictions your respective jurisdictions might have. And cost. – Duston Jun 10 at 12:59
• Ham radio is a great solution to many emergency situations but it is not likely to be the most practical for targeting a particular individual in an emergency. Since emergencies are never planned, the other end of the comms must be actively listening on a given agreed upon frequency all the time. I would consider ham radio way down the list for this sort of thing. Alternatively, assuming that you can communicate with any other party (anywhere) that then can contact your family by other means (phone) then ham radio is an OK solution (but, not the best). – K7PEH Jun 10 at 14:53
• Another important factor is the geography. Are there any hills, rises, walls of tall buildings, etc. directly in between the two sites? Can you mount two 9 dB gain yagi's, 10M AGL or more, at both sites? – hotpaw2 Jun 11 at 0:15
• I live on a mountain and there is a lot of Tennessee river between both of our locations. They live in a valley at the foot of a mountain. Hope this helps and I do really greatly appreciate the welcome and all of the comments! – Casey Jun 11 at 1:26

With 2 meter FM and common 50 W base or mobile transmitter power and plain vertical quarter wave antenna, range over flat ground to a similar station is roughly twenty-five miles, or forty km (limited mainly by line of sight and horizon scatter). Raising the antenna will increase this, but not dramatically. Repeaters in my area that are roundly 1500 feet (~450 m) above average terrain have only about a forty to fifty mile (65-80 km) range to car-mobile rigs of similar power, and then only without intervening terrain.

What you need with the terrain and tower you describe (assuming the mountain your relatives live at the foot of isn't between the two stations) is a directional antenna. A very modest Yagi at the higher end can give enough gain (both in transmit and receive) to give pretty reliable ground diffraction contact at forty miles (65 km) with fifty watts on 2 meter FM. This makes you independent of repeaters.

Also very important is to ensure that both stations have emergency power -- at the least, a substantial battery backup, kept charged and tested regularly (a single car battery will run a 50 W transceiver, mostly receiving, for a couple days).

• by the way, very nice 2M yagi directional antennas can be easily DIY-built using materials salvaged from ordinary (old school) VHF rooftop TV antennas. There are several sites on the web with instructions on how to do this. I built one from these plans and with 50 watts on 2 meters, I can hit a repeater almost 80 miles away. If you had two of these on tall poles, aimed properly at one another, you'd be set. – niels nielsen Jun 14 at 3:46
• An excellent answer. I'd add that one may want to consider adding some kind of digital communications to have the ability to leave some kind of text message in case the person is not at the radio at the time. I'd also add a mention to consider non-Amateur options like CB, GMRS, or maybe even business band. I will also emphasize emergency power should be a priority. – MacGuffin Jun 16 at 14:11
• Thank y’all so much that is very helpful I may end up building a nice yagi vs buying one. I ended up this week going with a yaesu FT-2900 radio that is 75 watts. Came in today so have a lot more before I can get it set up. I do have a couple of 12v car batteries I keep fully charged at all times with two power inverters for use of power outages. Would like to get a couple of solar batteries and a few 100 watt panels. – Casey Jun 17 at 23:41

For VHF or UHF, your range is mostly going to be limited by terrain, like Zeiss Ikon writes. On flat terrain the radio horizon can be estimated by a simple formula, but that's not of much use if the terrain isn't flat.

So, you can use a tool such as heywhatsthat to see what terrain is visible from where. If you have a clear line of sight over the path between the stations, just about any VHF or UHF radio should do. If you only just barely don't have line-of-sight, you may still be able to communicate with enough power and antenna gain.

A more sophisticated method to predicting propagation is the Longley-Rice model. There used to be some free online tools for this, but they've all gone away.

Alternatively, HF ground wave or NVIS could provide reliable communication at this range regardless of terrain. A 100W transmitter and a simple dipole in a tree would do nicely. You can play with VOACAP to run some specific scenarios.

• Thank y’all so much for all the very helpful answers. I now know more of what I need now for us both than before. Now to just decide on what radio to go with. Also do y’all recommend a linear amplifier and if so what kind of wattage do you recommend? – Casey Jun 12 at 18:27
• @Casey for 40 miles, not necessary. – Phil Frost - W8II Jun 12 at 21:54

At 40 miles (65 km), assuming that terrain doesn't get in the way, you have a choice between HF and VHF/UHF. For HF the radios are expensive, maybe \$600 for a good used one, and a simple wire antenna and coax would cost about \$150. Several HF radio models also include VHF/UHF. The antenna could be strung up between two trees. You could talk to half the hams in North America fairly easily, and hams in further places with persistence and skill. Terrain isn't usually an issue, unless you're deep in a valley.

For VHF and UHF, the radios are less expensive; a good used one can be had for \$100–\$200. At 40 miles (65 km) you could talk through a repeater with inexpensive omnidirectional antennas (say $80 for the antenna and coax), or directly through directional antennas mounted up high (20' or 6 m would probably do), which might cost \$120 for antenna and coax. This assumes that the directional antennas are aimed at each other, and that terrain doesn't interfere. If you get directional antennas, you might also want omnidirectional antennas so you can talk to locals in all directions.

The price estimates are for one radio and one antenna, so if you must also pay for the equipment at the other end then double your estimate. Personally I'd budget at least another \$100–\$200 for miscellaneous items such as coaxial connectors, rope, shipping fees, nuts & bolts, etc.

I would echo @ZeissIkon's advice about emergency power: radios are useless without it when the power grid goes down. I'd also suggest joining the local ham community, if for no other reasons than using the radios regularly and learning how to fix common problems.

• Very good advice there on the different bands vhf, uhf and hf. I've went with the yaesu ft-2900 radio. I’m wanting to buy or build a tower to mount a yagi and possibly another antenna for local like you explained as well. I am a prepper and the one thing I have definitely waited on learning about is all the ham radio stuff. So much to learn seems very complicated to a beginner like myself. This post was a great place to start. Thank all of you guys. Awesome community! – Casey Jun 17 at 23:47
• You're welcome Casey! Please upvote any answers you found helpful, and if you feel that your question has been answered satisfactorily, then you can "accept" one answer by clicking the check mark by the answer. – rclocher3 Jun 18 at 0:35
• You might not need a full-on tower Casey, a pole or a tree might work. If you have a pole that seems wobbly, you might be able to stabilize it with guy ropes or wires. – rclocher3 Jun 18 at 0:39