dosw

I cannot explain why your experience with Chirp would be so different from mine, for the same radio. I have the vendor set to Baofeng, and the radio set to 5RM. I set channel 193 to 121.300, named it AirGround1, and immediately the software selected "AM" as the mode. I set Duplex to "off" which disables transmitting (though the radio won't transmit, regardless). I saved the image. I uploaded it to the radio. I turned on the radio and selected channel 193. It has AirGround1, and it can hear ground control traffic. That's with Chirp next-20240919 on Python 3.12.3. Could you try with that configuration? My radio is firmware version v0.14. Hardware version v01.

Can't speak definitively to programming airband frequencies, as I haven't tried setting up specific ones. But on my version of Chirp, the Vendor setting should be Baofeng, and the Model should be set to 5RM. If you don't have this configuration you might be running an old version of Chirp. You're using Chirp-Next, right? I can say that when I tried programming 118MHz into Chirp for this radio, Chirp automatically selected "AM": I set Duplex to "off", as that's actually the setting that disables transmitting, though I'm fairly certain the Baofeng won't transmit on airband AM frequencies either way. I haven't tried uploading it to the radio. But Chirp does accept the frequency and auto-selects AM.

Yes. My 2021-era USB-C style MXT-275 uses wideband FM for the repeater channels with the stock firmware. Don't believe everything Midland's support communicates. They're often just wrong. There is no way to *set* wideband or narrowband on an MXT275 with stock firmware. But I've tested several ways that I've mentioned in other threads, and have verified that it does switch to wideband on the repeater channels. I've seen support messages posted here and there that are confusing, probably because support, themselves, are confused by the fact that you can't set it explicitly. The FCC signal description is: 16K0F3E - Frequency modulated (FM) analog voice, 4 kHz deviation (NPSPAC); (FM mode) The FCC test report is here: https://fcc.report/FCC-ID/MMAMXT275/5301846 You'll find that 4kHz deviation is wider than "narrowband", which must remain within 2.5kHz deviation. A narrowband transmitter would be classified as 11K or 12K, not 16K. Additionally, the test results in the document I linked to showed its bandwidth envelope at significant levels to be within 16kHz, which is again wider than 11K or 12K you would expect to see of a Narrowband radio. It is true that a full wideband implementation would be a 20K envelope / 5kHz deviation. But it's quite common to find "wideband" radios with a 16K designation like this one. I don't love the MXT275. I'm particularly annoyed that you can only set one repeater per channel. But it's a solid radio, works correctly out of the box with minimal configuration, and very little to screw up.

Tested again in the 467 0.5w channels, also didn't see a difference. Then I switched to the RTL-SDR because the software is easier to take a screenshot of. Also this time I spoke into the mic rather than just keying up. I think that was where my previous measurements fell down. Within the waterfall (the lower section of the screenshot) there are two transmissions. The top transmission (more recent in time) was narrowband, the bottom transmission (more distant in time) was wideband. You can see the bandwidth peaks are wider. The red shading above is a 20kHz span, 10kHz deviation. The actual deviation of the radio is supposed to be around 2.5kHz in narrowband, and up to 5kHz in wideband. I see some difference when measured this way. In this example I fed the radio on low power mode into the 61.5dB attenuation, and then into the RTL-SDRv4 on channel 19, and used SDR++ to observe the waterfall.

I have a Baofeng UV-5G Plus. I set it to channel 15 / 462.5500 and tested it in narrowband mode, as well as in wideband mode. I've been able to observe bandwidth using a TinySA with other radios (Retevis RA87, Baofeng UV-5G --not "plus", and MXT275). But with this radio I don't see a difference in transmissions between a narrowband and wideband setting. The test setup: Baofeng UV-5G Plus -> 10w 40dB attenuator -> 10w 20dB attenuator -> TinySA TinySA is set to center frequency of 462.5500, span of 12kHz, -61.5dB attenuation offset*. Here are a couple pictures of the TinySA: Narrowband setting for the UV-5G Plus: And by comparison, here is wideband: See the difference? I don't. * (At 12kHz it still shows a broader band, because there's room on the screen. At 25kHz span, it's still identical). * (-61.5dB, because my NanoVNA says that my total attenuation is -61.5dB, not "40+20=60".) Is the radio just not switching to narrowband?

This has been my experience, too. I tested this four different ways using an RTL-SDR with SDR++ software to observe the waterfall, using the NanoVNA as an RF generator, using the TinySA to observe output, and so on. The USB-C version of the MXT275, which I've had since late 2021, uses wideband in the "R" channels.

Not true. It quietly switches to wideband on repeater channels. I confirmed this looking at an RTL-SDR waterfall, watching a TinySA spectrum analyzer, but first by observing that listening to 15R sounds just a little quieter than 15, which is a hard symptom of switching to wideband to explain, but expected. Ultimately do what you want. But the problems you're facing have nothing to do with using the simplest 15w mobile radio made. There are fantastic alternatives, of course, but you're in analysis paralysis right now. Just use the thing.

Yes. Out of the box the 275 doesn't have repeaters enabled. To set it to use repeaters you must go into the menu by pressing the Menu button, then up or down arrow until you arrive at "Rp" which will probably have a value set of "off". Hit the lock button (that's like "enter" on the Midland menu system). Now you're able to use the up/down arrow (on the volume rocker) to set "on." At that point repeaters are enabled. As a person pages through the channels using the arrows at the top of the mic, they will see 1, 2, 3, 4, 5, 6, 7, 15, 16, 17, 18, 19, 20, 21, 22, 15R, 16R, 17R, 18R, 19R, 20R, 21R, 22R. The repeater he is hearing will be one of those 15R-22R channels, though he will also hear the repeater on one of the 15-22 channels, since simplex and repeaters both use those same frequencies. Once he's selected the correct R channel, he will need to go into the menu again and set Tx and Rx tones. The manual only shows Pt but when on a Repeater channel, it will have Rx and Tx Pt tones. The options will be off, ∿, and ⎍. The first one is for PL tones, and the second one is for DCF tones. The user will have to look up in his manual how to translate conventional PL and DCF codes into the appropriate number options for Midland.

Don't second guess your purchase yet. The possible factors are: * Others have tones set and you don't have the same tones set. * Others are on a repeater and you're just talking on a simplex channel, also without tones. * Nobody wants to talk to a random stranger yet. * Poor signal propagation. * 800 other things not related to a defective radio. * Bad installation (severed coax for instance) * 200 more things. * Finally, maybe a defective radio. But if you can hear the radio on another GMRS or FRS radio such as a cheap handheld, it's not probably defective or in need of updating. It's one of the other 1003 factors. You have a simple and reasonably good quality radio.

There are some nuances I haven't seen mentioned. One is that the "strongest signal" is the strongest from the perspective of the receiver. Another is that two comparable signals will cause strange intermodulation. You hear that when two kids both key up their cheap FRS radios at the same time in different rooms of their house.A nearby listener will hear odd sounding interference. Last, even if you have squelch tones set on your receiver, you may still hear unwanted transmissions. Sometimes someone will transmit the code necessary to open squelch on your receiver but the stronger (different, unwanted) signal will be what you actually hear.

I was setting up 2m and 70cm repeater in a radio, and while my area has a really thorough website enumerating repeaters and their locations, it was hard to know which ones have propagation useful to me, and how they're used in practice. Rather than program them all into a scanner I used an SDR to observe swaths of those bands all at once. Then as CW call signs got transmitted, or as nets occurred, 8 could see them in the waterfall while listening. It was also possible, by doing this, to see what repeaters are interconnected. If two or more show up at almost exactly the same time, you've found connected repeaters. Anyway, I mention this because with one SDR I can see all of the 462 range. With two I can see 462 and 467. It takes two cheap SDRs to cover lower and upper MURS. SDRTrunk software can manage multiple SDRs, or running two instances of SDR++ can allow you to visualize the entire lower and upper MURS bands.

It's just two channels over from the baby monitor net, one down from the Tuesday Mr Microphone Simplex group. MURS net? That's the Walmart all hands meeting. Sorry it was just funny. You should be able to scan for it Monday.If you don't hear it, it's because it's too far away, and MURS doesn't have repeaters. You're allowed external antennas with MURS, though, so you might try using one, and getting it as high as you can. I imagine people doing a MURS simplex net are tinkering with external antennas to see what kind of range they get. Can you get to higher ground somewhere close, like an overlook point? That may help in hearing it so you can ask the participants a few questions. Also, if you hear it mentioned in the GMRS net, you could check in with that net and ask for more details.

I bought a 24pc assorted adapters kit, plus a few SMA-M and SMA-F to PL259 and SO239 short cables, and a few PL259 to PL259 short cables. Less than $60 for all that. At this point I never run into things I can't connect to my NanoVNA, TinySA, and SW102. But your connectors are possibly more esoteric. Nevertheless you should be able to find adapters for them on Amazon, which is where I found all the other assorted adapters.

You shouldn't have to specify an input frequency for the repeater, you should set your radio up with the output frequency: 462.xxxx, the offset: +5MHz, and the tx/rx tones. RX tone is not as important except that it will help you reject hearing kiddies playing walkie talkie. What radio are you setting up, and what software are you using to do it?

I have a TinySA that has been kind of fun to figure out and test with. I received a couple of attenuators today through Amazon, and have finally been able to hook a radio directly up to the TinySA rather than just receiving through its antenna. However, I'm seeing power output levels that don't really make sense, from the radio I'm testing with. The attenuators I got are SMA 10w 40dB DC-3GHz and SMA 10w 20dB DC-3GHz (a 40dB and 20dB attenuator). The test hardware: TinySA SMA 10w 40dB DC-3GHz attenuator Baofeng AR5RM radio set to mid power (typically measures around 5w with my Surecom SW102). Whatever connectors are needed to get them connected to the TinySA. Pre-setup: I calibrated my NanoVNA, and then tested the attenuator along with the cables I'm using with my NanoVNA and measured the attenuation to actually be 41.5dB. Configuration: Radio -> 40dB attenuator -> short SMA-M to SMA-M cable -> TinySA device. TinySA: "High" mode (UHF), Level/ExtGain=-41.5dB, Frequency/Center 467.6750, Frequency/Span 18kHz (doesn't seem to matter even if I set 500kHz), Units: Watts. Radio: Mid power, GMRS repeater 20 / 462.6750+5=467.6750MHz output. Test: Key up the radio at mid power. I expect to see 5w. I see 2.304w. Key up radio at high power. I expect to see just a hair under 10w. I see 2.304w. Key up radio at low power. I expect to see 2.5w. I see 1.631w. Plug the radio into my SW102 with a 50w dummy load on it and retest (no attenuation): High: 9.7w Mid: 5.1w Low: 2.6w Connect to the TinySA again, this time with a 40dB and 20dB attenuator inline: Radio -> 40dB attenuator -> 20dB attenuator -> short SMA-M to SMA-M cable -> TinySA device TinySA: "High" mode (UHF), Level/ExtGain=-61.5dB, Frequency/Center=467.6750MHz, Frequency/Span=18kHz (also tested with 500kHz), Units: Watts. High power mode: 10.29w Mid power mode: 4.601w Low power: 1.83w I don't expect things to line up exactly with the SW102. And there's no telling which is more accurate. The old words of wisdom are "Never take two chronometers to sea, take one or take three." I've got the equivalent of "two chronometers" (no third opinion to help form consensus). But what is interesting to me is that I really do have to use both the 40dB and 20dB at the same time, and calibrate the offset to -61.5dB to get an accurate reading. The TinySA is supposed to be able to handle up to +10dB input. With only the 40dB attenuator, am I getting too close to that +10dB? As I calculate where I should be in dBm input, I 10w=40dBm, minus 40dB attenuation should bring me to 0dBm with no ext gain adjustment. And 5w is 36.99dBm. 36.99-40=-3.01dBm. In both cases, I shouldn't be approaching the danger zone for the TinySA with just the 40dB attenuator. Yet I only seem to get accurate readings if I use both the 40dB and 20dB attenuators in series. Finally, I did test the two attenuators in series, through my NanoVNA, and they came in very close to -61.5dB when connected in series.

This is exactly why I prefer not to use direct chat. The other (less common) reason is sometimes there's no end to it.

I wouldn't do direct chat. But why don't you post a few questions and we can see about knocking out answers for them? At its most basic: Get a license (which you have). Get two radios. Set the two radios to the same channel. Set no squelch tones (aka, privacy tones, ctcss tones, privacy codes, subchannels, dcs tones). None. You and your communications partner go a few hundred feet away from each other with the volume where it is comfortable. One of you pushes the button on the side states his call sign, and asks if the other can hear him. The other pushes the button on the side of his radio, states his call sign, and says yeah I hear you. You're good to go. Next step, if you start hearing lots of construction crews and kids playing walkie talkie, you both select a squelch tone and set the radios to that tone. Now you will only hear each other (everyone can still hear you though). Then you come to the realization that you can only hear each other a half-mile to a handful of miles away, and not reliably. So you come to mygmrs.com and find repeaters in your area. You submit a request to the repeater's owner to use the repeater. He or she grants the request. Then you set one of the repeater channels in your radio correctly. You'll have questions on how to do that. Ask when you're ready.

Laird divested of its consumer antenna business, which is now TE Connectivity. At least that's what I found out dealing with their support.

dB difference = 10*log(p2/p1) 10*log(50/7.8) = 8.07dB 10*log(50/5) = 10dB At least that's how I understand it. And every 3dBi is a doubling.

The Comet GP3 is also well reviewed for use with GMRS: https://forums.radioreference.com/threads/comet-gp-3-analysis.430168/

I see no problem with these, though I would prefer an NMO-mount solution for ease of swapping antennas. Today you might want a 6dBi gain 34" whip. Tomorrow you might want a Ghost antenna so it's not as much of a big deal when you drive around town. And next week you might just want a weatherproof NMO cap so you can go through the car wash. The adapter you want, for your Baofeng UV5G Plus is SO-239 to SMA-Female. The set you linked to is a two-pack, one of them being SO-239 to SMA-Female, and the other being SO-239 to SMA-Male. You don't currently need the latter, though one can never have too many adapter options.

That sounds very sad ham-ish, indeed. And at this point, it's been 19 years. I imagine that a substantial portion of the Extra class operators who looked with fondness upon the CW requirement as a rite of passage, have already found safe passage into the pearly gates.

It's possible they misdirected my inquiry. As I dig a little deeper, the Laird TE B4505CN is now made by TE Connectivity, so it sounds like their mobile antennas spun out to TE, while their internal equipment spun out to Enzurio, which I guess is a division of Dupont now. Trying again...

https://www.ezurio.com/?utm_term=laird connectivity antennas&utm_source=google&utm_medium=cpc&utm_campaign=ezurio-rebrand-search&gad_source=1&gclid=Cj0KCQjwiuC2BhDSARIsALOVfBKIBJ0dKgXXkEyA2TgibvUWVWMHXHgOHsxggDU1lyE4CXW-g2FjPFMaAkqAEALw_wcB It looks, from the Enzurio site that Laird mobile antennas aren't even offered anymore. I found out when I emailed Laird support with a question and they responded with the following: You're looking for information on a Laird Connectivity part. LPM has since divested from Laird Connectivity. They now go by Ezurio, as a matter of fact. See link below. Good luck! Ezurio | Formerly Laird Connectivity Chuck REQUIRES IMMEDIATE ATTENTION: The Laird.com and Lairdtech.com email addresses will be retired on June 8th, 2024. This includes any direct emails to a person as well as our "DL" email format. Please note that the new dupont.com email addresses are not the exact replicas of the previous Laird.com or Lairdtech.com email addresses. Please use the email below if you are not sure of the new "DL" or direct persons email address. laird.sales-inside@dupont.com Regards, Charles Aussem Technical Service Engineer

I made the assumption that this question: "is there a gmrs mobile radio that has air frequencies to listen to" is asking for a 2-way GMRS radio, that can also listen to air frequencies. The AR-5RM is not a GMRS radio. And though it can be configured to transmit on the GMRS frequencies, it exceeds the GMRS power limit by 5x on channels 8-14. So if he's asking for a GMRS radio, that one should be out of the running unless he is ok with not using it for transmitting on those frequencies. It will, however, listen to air band, GMRS, and so on just fine. I still like the radio. But someone who wants to buy a GMRS radio that also listens to airband should know that they're getting a radio that doesn't provide a way to stay within the power requirements of GMRS.