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For GMRS: 64 miles from my home to the Promontory Point repeater. But I can easily drive another ten or twelve miles further out from it and still hit it, so 76 miles. But it is at least a couple thousand feet over the terrain around it. For 2m ham, the Snowbird repeater is an Intertie repeater. The repeater itself will reach Nevada and Wyoming (from the middle of northern Utah). But it's also tied into a linked network that extends into Oregon, Washington, Idaho, Nevada, Wyoming, Colorado, Arizona and Montana, with multiple nodes along the I-15 corridor from Ogden to Provo. The Snowbird repeater is at 11k feet, with the valleys below at 4200-5200 feet. So propagation is pretty amazing.

Yeah, nobody's really watching GMRS that closely. Even amateur. But I'm guessing if you looked at the enforcement database for hits on marine VHF and aviation there would be some stories. Marine VHF has become less strict in the past decade; it used to be that you weren't allowed to talk ship-to-shore except to licensed shore stations. But a web search says that "In 2016 the FCC relaxed its rules and now allows portable VHF radios to be used “in areas adjacent to the water” when this use relates to the “needs of the associated vessel."

That radio is not made for transmitting on airbands, and it is, in fact, illegal to use it for transmitting within the airband. There are a lot of areas where you may get away with dumbassery, but transmitting on an aviation frequency with a UV5R is likely to be one of those areas where you won't get away with it very long. https://aviation.stackexchange.com/questions/94091/what-licenses-do-i-need-to-transmit-on-airband-frequencies

This has been my experience, as well. There are better radios out there for a lot more. And there are worse radios for a lot more. There are not many better radios for less. I use mine with the stock antenna or a 771 depending on the situation. The UV5G Plus is the GMRS-correct, type approved version, of course.

There's this one from DX Engineering: COMPACtenna Model 2m/440 Dual-Band NMO Mobile https://www.dxengineering.com/parts/can-2m-440?seid=dxese1

Meter was connected backwards? The radio was on the antenna side of the meter, and antenna on the radio side?

For portability get a Uniden scanner. It will scan 25-50 channels per second. The Baofeng will scan 3 per second. And the Uniden will cover from 10m (maybe even 11m) to 33cm. For "as many frequencies as possible", an SDR. Even the lowly RTL-SDRV4 will pick up from 300kHz to 1.72GHz, with some antenna swapping necessary to get all that.

What are you trying to accomplish? Ham radio in the US, for the bands this radio is compatible with, is going to be 144-148MHz, 222-225MHz, and 420-450MHz. If you are transmitting because you have your amateur license, you would probably want a dual-band 2m/70cm antenna. If you are just listening, it's not as important to have a perfectly matched antenna. But typically an antenna like a discone antenna will cover a broad enough range to be useful from 108-509, for listening. If you are using the radio for GMRS the antenna should cover 462-468MHz. Again, a discone could be a pretty good antenna for 2m, 1.25m, 70cm, and GMRS. Or the Comet CA2X4SR. Both a discone or the comet will be external antennas. For built-in antennas a Nagoya or even abbree would be fine so long as it's listed as working for the bands you intend to transmit on. There are a lot of other ham bands that are outside of this radio's capacity. But it covers the most common ones used with a Tech license.

Awesome. We've got a mountain between us (I'm in east Sandy near LCC), so I won't be able to hit it or hear it, but when I get down that direction I'll give it a listen.

Per antenna height. a 100ft antenna has 14 miles line of sight to someone laying on the ground below. But it has 28 miles to another 100 foot antenna.

I have the Ghost antenna (MXTA25), the whip (MXTA26), and the Comet CA2X4SR-NMO. On my old '95 Bronco I use them with a lip mount on the hood that is just forward of the air-vent cowl. The ground-plane that provides is a minimum of eight inches to the aft, and more in all other directions. I find the best of the bunch on GMRS is the MXTA26. The CA2X4SR-NMO is invaluable as a dual-bander/broad-bander, though; great for 2m/70cm plus GMRS (different radios, sure). I don't really use the Ghost all that often anymore. It was okay. SWR was a little higher than the others, and as I drive around testing propagation by recording at home what the signal sounds like, I just get more umph out of the bigger antennas. Plus, where I have it mounted on the Bronco, my FM Stereo's antenna is still longer than the MXTA26. But the Ghost isn't bad. If I'm in a group where we're within a couple miles of each other, I don't need anything better. And actually if I'm parked in the lot at a ski resort, the Ghost is probably a better option for reaching someone on the slopes, since the mountains can be so abrupt.

Yeah, that's the hard part. We had two windows today, but it will be a few days before the next good one, and probably in the middle of the night. A few weeks ago I heard Sunita Williams taking questions from school kids and answering them. I guess some ham operators were volunteering at various schools to facilitate. This wasn't on the repeater, it was on their 2m/70cm amateur frequency pair. Pretty cool. From what I've read, the ISS repeater and amateur voice downlinks are transmitting at 25w. Pretty amazing that a 25w FM voice transmission over UHF can reach me over 2000 miles away and be readable, when I'm using nothing more than a mobile antenna and a small LnA.

I should also mention: What YOU need to be able to do this... Although an SDR is really, really convenient for listening, because it allows you to observe the waterfall, I have also listened to the ISS with a Baofeng amateur radio (AR-5RM), the same antenna, a few adapters, and the same tiny linear amplifier, this time powered with a micro-USB cord. You still have to set your frequency step as narrow as possible in VFO mode, start high, and step down as the Doppler shift sweeps down. But it's not hard to do. Turn off squelch. Parts list: AR-5RM (<$30), LNA (<$20), antenna ($80), mount ($30), a couple of adapters ($10): still about $170. (And you'll need your Amateur Technician license -- ham)

There are a few websites on this topic, but I just had a fun experience and thought I'd mention here what was involved. Background: The ISS operates an amateur repeater. The downlink for that repeater is at 437.8000 MHz. What you will hear on that repeater is mostly people trying to make DX contacts through the repeater. As an example, if I can hit the repeater 400 miles away, and someone else can respond back, from 400 miles away, we could have 800 miles between us (not counting the 260 mile trip to space and back). An 800 mile contact over VHF through a single repeater is kind of cool, so amateurs are working this repeater constantly as it passes near enough to reach. Today's pass, the one I heard, was never any closer than Calgary, Canada (I'm in Salt Lake City). The measuring tool on Google Earth put the land distance at about 850 miles. And if you calculate the hypotenuse of 850 miles base plus 260 miles elevation that's about 888 miles. Accounting for the curvature of the earth changes the angle of that 260 mile leg, changing the shape of the triangle, and making the hypotenuse (the distance from me to the ISS) closer to 950 miles. I wasn't trying for contact; I assumed it was too far away, which it probably was for my setup. But I started hearing it before it hit the west coast of British Columbia, Canada, and kept hearing it all the way to New Brunswick. That's well over 2400 miles maximum distance. How do you know you're hearing the ISS repeater? First, you'll hear it starting to show up at the approximate fly-by time here: https://spotthestation.nasa.gov/tracking_map.cfm Next, you'll notice that the transmission is coming in off-center from the downlink frequency. This is due to the Doppler effect of the ISS moving 17,000+ miles per hour. Today when I first started hearing it, it was coming in at 437.8065 MHz, and by the time it faded out, I was listening on 437.7935 MHz. That's a 13kHz Doppler shift (+6500Hz to -6500Hz). Sensing that Doppler shift pass from above the center frequency to below the published center frequency is a dead giveaway you're dealing with the ISS moving 17500MPH. But here's what's cool, in my mind. My setup wasn't extravagant: RTL-SDRv4 (<$40) with SDR++ software (free). Cheap no-name (<$20) inline linear amplifier powered by the Bias-T setting of the SDR. And the big massive antenna? Hold onto your britches: Comet CA2X4SR-NMO mobile antenna ($80) mounted on a Midland magnetic mount ($30) stuck to an old 16" square steel griddle. Laptop computer to run the SDR and its software. Total cost (excluding laptop): $170, all of which I have cobbled together already. My technique was just to look up the fly-over time, and set the SDR++ software to just a few kHz high, then start watching the waterfall and listening. When I started seeing the FM signal in the waterfall I centered on it and listened. And by watching the waterfall I was able to continually adjust the frequency center through the fly-over until it was out of range. It was amazing to me that I was able to follow it all the way from the west coast of Canada to the east coast, and that I did it with a simple mobile antenna just sitting on the window sill -- not even a yagi. I wasn't expecting to hear anything at this time since it never got closer than about 950 miles. The pile-up on the frequency was pretty heavy, so I imagine the people getting through are using good, directional antennas to transmit with. I don't expect to be able to get a contact out of it without a directional antenna. But it was impressive to me today to be able to hear it over such a great distance.

This is what you're looking for: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-95/subpart-J "The highest point of any MURS station antenna must not be more than 18.3 meters (60 feet) above the ground or 6.10 meters (20 feet) above the highest point of the structure on which it is mounted." Other interesting sections: "A grant of equipment certification will not be issued for MURS transmitters capable of operating under both this subpart (MURS) and under any other subparts of this chapter (except part 15)." (We know this; MURS type approval precludes being approved for transmission in other bands, and vice versa.) "Each MURS transmitter type must be designed such that the transmitter power output does not exceed 2 Watts under normal operating conditions." "A MURS transmitter must transmit only emission types A1D, A2B, A2D, A3E, F2B, F1D, F2D, F3E, and G3E. Emission types A3E, F3E and G3E may include selective calling or tone-operated squelch tones to establish or continue voice communications. MURS transmitters are prohibited from transmitting in the continuous carrier mode." What do those mean? A1D = AM, 1-channel digital without subcarrier, data, telemetry, or remote control A2B = AM, One channel digital with subcarrier, telegraphy (such as teletype) A2D = AM, one channel digital with subcarrier, data, telemetry, or RC. A3E = AM, one channel analog, voice. F2B = FM, one channel digital with subcarrier, telegraphy (such as teletype) F3E = FM, one channel analog, voice (this is what most people are buying 2-way MURS radios for) G3E = PM (phase modulation), one channel analog, voice "The occupied bandwidth of emissions transmitted on the center frequencies 151.820 MHz, 151.880 MHz, and 151.940 MHz must not exceed 11.25 kHz. The occupied bandwidth of emissions transmitted on the center frequencies 154.570 MHz and 154.600 MHz must not exceed 20.0 kHz. The occupied bandwidth of type A3E emissions must not exceed 8.0 kHz." (Narrowband FM for channels 1-3, Wideband FM allowed for Blue and Green, AM has to be 8kHz or less.) This section talks about unwanted emissions: https://www.ecfr.gov/current/title-47/section-95.2779 ... and it has some interesting information about audio filtering to avoid interference.