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Really impressed with the custom firmware people are developing for this radio. The one I am on now is written by egzumer and even comes with a spectrum analyze

Really impressed with the custom firmware people are developing for this radio. The one I am on now is written by egzumer and even comes with a spectrum analyzer. Unfortunately, the radio itself is about what you would expect from a $30 import. The frontend easily overloads, and the harmonics on transmit are way outside what the FCC permits. Still, as a gateway into ham radio, it is one hell of a value proposition.

topspin 3y ago
> way outside what the FCC permits Confirmed. And yet it has an FCC ID from early 2023... https://fcc.report/FCC-ID/XBPUV-K5 https://fcc.report/FCC-ID/XBPUV-K5
- drmpeg 3y ago
  The FCC doesn't test the transmitter. The device is only tested to comply with Part 15 unintentional radiation rules (just like any other consumer electronics device).
jcrawfordor 3y ago
Have you been able to perform testing? I think the quality of these Chinese radios has actually improved quite a bit over the years, and the reports I see of testing UV-K5s shows them within FCC limits (well within for 2M, closer to the limit for 70cm). The situation is much worse if you transmit outside of those bands, but, well, that's not really what it's designed for anyway. You have to be cautious with harmonics reports on these radios because a lot of people seem to try to evaluate them with an SDR... and they are pretty much guaranteed to overload the SDR's front end and cause all kinds of intermodulation that people mistake for emissions of the radio. I wish ARRL still put more testing pieces in QST because it's hard to know what to make of the testing reports you see online. People end up finding all kinds of different results, and I'm sure there's variation between units, but it also seems like there's a big aspect of... random internet people unsurprisingly having inconsistent test setups.
- transcriptase 3y ago
  > You have to be cautious with harmonics reports on these radios because a lot of people seem to try to evaluate them with an SDR... and they are pretty much guaranteed to overload the SDR's front end and cause all kinds of intermodulation that people mistake for emissions of the radio. This is something more people should know. On the most popular USB SDRs even a local FM radio station will have the appearance of transmitting on harmonics, which I know for certain the serious hams would report within hours.
  - windexh8er 3y ago
    > ...which I know for certain the serious hams would report within hours. In reality this is a myth. There are very few people who go to this length. And even the serious Hams will need some serious gear (e.g. KrakenSDR) to pinpoint quickly. Lots of Hams take themselves way too seriously. Folks like NotARubicon on YouTube do a good job of calling it like it is.
    - transcriptase 3y ago
      I’m not sure about where you are, but here the scene is littered with retired electrical engineers, former broadcast professionals, and military comms specialists with tens of thousands of dollars worth of high-end transceivers, vnas, and small antenna farms. And my point was that the guys with serious gear would quickly notice if a local fm country station was actually transmitting in the amateur bands like a cheap SDR might incorrectly show.
      - windexh8er 3y ago
        Feel free to send over any fines given out by the FCC within a thousand miles of where you are. There likely aren't any any in the last decade or ever, and this is all public record. Hams are great at scaremongering. They're friendly for the most part, but there are always "some people", especially on air.
        3y ago

topspin 3y ago

> way outside what the FCC permits Confirmed. And yet it has an FCC ID from early 2023... https://fcc.report/FCC-ID/XBPUV-K5 https://fcc.report/FCC-ID/XBPUV-K5

drmpeg 3y ago
The FCC doesn't test the transmitter. The device is only tested to comply with Part 15 unintentional radiation rules (just like any other consumer electronics device).

jcrawfordor 3y ago

Have you been able to perform testing? I think the quality of these Chinese radios has actually improved quite a bit over the years, and the reports I see of testing UV-K5s shows them within FCC limits (well within for 2M, closer to the limit for 70cm). The situation is much worse if you transmit outside of those bands, but, well, that's not really what it's designed for anyway. You have to be cautious with harmonics reports on these radios because a lot of people seem to try to evaluate them with an SDR... and they are pretty much guaranteed to overload the SDR's front end and cause all kinds of intermodulation that people mistake for emissions of the radio. I wish ARRL still put more testing pieces in QST because it's hard to know what to make of the testing reports you see online. People end up finding all kinds of different results, and I'm sure there's variation between units, but it also seems like there's a big aspect of... random internet people unsurprisingly having inconsistent test setups.

transcriptase 3y ago
> You have to be cautious with harmonics reports on these radios because a lot of people seem to try to evaluate them with an SDR... and they are pretty much guaranteed to overload the SDR's front end and cause all kinds of intermodulation that people mistake for emissions of the radio. This is something more people should know. On the most popular USB SDRs even a local FM radio station will have the appearance of transmitting on harmonics, which I know for certain the serious hams would report within hours.
- windexh8er 3y ago
  > ...which I know for certain the serious hams would report within hours. In reality this is a myth. There are very few people who go to this length. And even the serious Hams will need some serious gear (e.g. KrakenSDR) to pinpoint quickly. Lots of Hams take themselves way too seriously. Folks like NotARubicon on YouTube do a good job of calling it like it is.
  - transcriptase 3y ago
    I’m not sure about where you are, but here the scene is littered with retired electrical engineers, former broadcast professionals, and military comms specialists with tens of thousands of dollars worth of high-end transceivers, vnas, and small antenna farms. And my point was that the guys with serious gear would quickly notice if a local fm country station was actually transmitting in the amateur bands like a cheap SDR might incorrectly show.
    - windexh8er 3y ago
      Feel free to send over any fines given out by the FCC within a thousand miles of where you are. There likely aren't any any in the last decade or ever, and this is all public record. Hams are great at scaremongering. They're friendly for the most part, but there are always "some people", especially on air.
      - 3y ago