WRNA236

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I think not enforcing the need to get a call sign had more to do with the decline of CB than anything.

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I agree that it shouldn't take $500 to get some of this stuff but I do think it's unreasonable to expect all the way down to a $20 radio. Bubble pack radios aren't even made to be repaired or aligned, they are use-and-toss. So expecting more than a basic user manual is at best hopeful. Also the talent you allude to is not limitless. If you want a radio to hit a price point there's only so many NRE hours they can afford to throw at it. So if you want the time spent writing manuals it will likely come at the expense of design or quality in the actual device. Same with including CPS. I'm one who thinks a radio should have free or reasonably priced software to program it but I also don't expect it to be a feature-rich experience. A basic tool to get the job done is fine.

How did your buddy program them? I'd have figured he'd be including CPS. Anyway, there's ways to work around band limits on many Motorola radios (even 1st gen XPR). It requires reading the radio and changing variables in that blank, generic code plug with a hex editor. You can edit and write the modified code plug all you want. The pain is it makes using CPS no longer a completely seamless affair in the future. If you don't have access or lose the original code plug file when you read the radio CPS will revert the code plug back to the default band limits for the radio and you have to start back at square one with hex editing. It's also important to note that just because two radios are both UHF the different band splits mean they may not necessarily be identical. So extending the limit up or down a couple of MHz is usually fine but forcing a 450-512 down to 403 might be way beyond the filter skirts and not work even if you trick the radio into tuning it. If you're just trying to make a radio tune for RX it shouldn't hurt anything. It may not be very sensitive way out of band though. Now trying to transmit that far out of band might be damaging, you need to be careful.

tl:dr: Some CCRs are really bad clinkers while others work reasonably well. That's the same situation as anything coming out of China, though. They'll make anything you ask them to make at whatever price point you want it to meet. So read reviews and test reports on this (or any) radio. If they work alright and seem well built then don't worry about the architecture. Long answer: Don't get wrapped around the axle about SoC or similarly the terms direct conversion, direct sampling, SDR, hybrid, double conversion, heterodyne, etc. The words are thrown around indiscriminately. Basically a good radio is a good radio no matter its architecture while a bad radio will be bad regardless. The RDA1846 chip that most of these radios use can perform adequately if the design is sound otherwise. It's one particular frequency agile wideband RF chip but not the only by far. There's tons of them now, some that cover HF to SHF. One I'm familiar with is an Analog Devices part that can TX and RX on 2x2 MIMO from 70 MHz to 6 GHz. It's not something intended for cheap consumer HTs though. The chip is $300 alone and a drop-in SoM (System on a Module) is $1,600... You might generalize saying it's easier to make a straight superheterodyne radio that performs fine but is less expensive. Mostly it's reliability and build quality that suffers. After decades of engineering churn there's not much fat left to cut in the fundamental architecture to significantly improve performance so all you're left with is using cheaper components. So it won't last as long being tossed around but the actual RF performance is indistinguishable otherwise. But such a radio is inflexible and doesn't lend itself to adaption to something else. DSP techniques are still evolving and proprietary. So there's a lot more ways to screw up a direct conversion radio. Algorithms and firmware are where established companies (Motorola, Harris, Yaesu, Kenwood, whomever) can really distance themselves from competitors. Motorola is probably using direct conversion in the XPR7000 and EVX models and it works well. But then again no one other than Motorola knows really what is inside their ASICs to know for sure. But the guts don't matter, they aren't able to bend the laws of economics, physics or engineering. What matters is where the rubber meets the road - does it work or not? And if they can do it other companies can, too. In fact Harris builds most of the high performance, high reliability radios for the military and one portable example, the AN/PRC-152 (Falcon III), is a highly frequency nimble (covers 30-512 MHz and 762-870 MHz without gaps) 5 watt TX SDR that can do several analog and digital modes, some of which (like APCO-25, amongst other things) were added with a firmware upgrade after the radio was accepted and put into service. That sort of flexibility is why SDR is where it's at. The reason these CCRs proliferate is once a basic design is done they can adapt it to just about anything. That comes with up- and downsides. They can just make them faster and cheaper or they can add interesting form factors or features, whatever. And even heterodyne architecture have DSP, so the line isn't really that distinct to say this-or-that. If you're still interested after that diatribe you can start digging into the engineering behind various architectures and RF generally here: https://analog.intgckts.com/wireless-receiver-architectures/

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We do recognize reciprocal amateur radio operating privileges, which generally require applying for a temporary license. https://www.arrl.org/us-amateurs-operating-overseas But AFAIK that's about the only global reciprocity from an individual's standpoint. There's agreements between the US and Canada for FRS/GMRS and commercial and public service on the border and on the Great Lakes. But those are special exceptions due to our proximity. Otherwise the FCC (and I think other countries) issue what are known as restricted radiotelephone operator licenses when you need to use radios internationally. These would be radio operators on aircraft or ships, for example, and not usually informal operators (e.g. hams). https://www.fcc.gov/wireless/bureau-divisions/mobility-division/commercial-radio-operator-license-program/commercial-0 I don't know either if there's a written rule on this but with ham radio it's AFAIK accepted that operating things like Echolink, IRLP or DroidStar that when you key a radio you need a license. IOW say you're talking on a mobile radio to someone via EchoLink on their computer you both still have to be licensed. The app is like a very long mic extension cable. GMRS is a little different in that the license covers a family. But GMRS has the stipulation that you cannot link radios via the PSTN, only non-interconnected VoIP or RF link. Since it's an app that doesn't require dialing it's probably OK but it's kind of fuzzy with the "non-interconnected" statement. But if you're not family then you'd both need a GMRS license either way and the FCC only issues those to citizens, so back to square one.

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You should record and post it. If it's periodic it's man-made and probably can be identified. It's possible there's nothing you can do about it. Interference like this is why subtones were invented in the first place.