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amnemonic / Quansheng_UV-K5_Firmware

Quansheng UV-K5 Firmware
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FM bands for hearing assistance #56

Closed gabeluci closed 10 months ago

gabeluci commented 11 months ago

My goal is to be able to use the UV-K5 for events that broadcast audio for hearing assistance in the range of 72-76MHz.

I have very little experience with radios. I thought I could do this out of the box, but this past weekend, I punched in the right frequency (72.9). But I heard nothing. I had to hit the monitor button to hear anything at all, but I got a lot of static and only barely heard what's going on amid the static. It basically wasn't usable.

I thought maybe I could use the "FM Radio" setting, but that doesn't go below 76MHz.

I think the difference is the bandwidth? I think normally it's using a bandwidth of 25kHz, but commercial FM radio uses 200kHz? But I'm pretty uneducated here, so I don't know.

So I think what I'd need is a way to extend the range of the FM Radio down to 72MHz. Is there a way to do that? I don't see that in any of the files right now.

Here's a link to the manual for a transmitter for this purpose: https://williamsav.com/wp-content/uploads/2020/04/ppa_375_manual_en.pdf

amnemonic commented 11 months ago

Hello @gabeluci,

inside UVK5 is chip BK1080 which can operate in these ranges:

  1. 87.5–108 MHz (US/Europe, Default)
  2. 76–108 MHz (Japan wide band)
  3. 76–90 MHz (Japan)
  4. 64-76MHz (except BK1080QB)

so I it seems that hacking firmware for radio to be able to receive band 4. will suit your needs. I can try to do this however I don't have any transmitter which works in that frequencies. Would you be able to flash and test modded firmware if prepared?

amnemonic commented 11 months ago

Please unzip and flash below firmware if it works. It should receive FM radio in range 64-76MHz:

k5_v2.01.26_FMRadio_64_76Mhz.bin.zip

gabeluci commented 11 months ago

Awesome. I'll flash it when I get home. I don't have a transmitter to test, but I'll see if I can find somewhere I can test it. It's a shame it can't be changed to 64-108, but this will do since I would never actually use it for commercial FM radio anyway.

gabeluci commented 11 months ago

I flashed it, and can confirm I can use the 64-76MHz range. I'll see if I can find an opportunity to test it out.

Thank you!

amnemonic commented 10 months ago

Thank you too for tests!