LY4SA My guess - VHF and UHF are nor filtered by switch and goes through while HF is filtered by internal circuit. Open your SDR switch and try to move short black jumper to other position then it is now. Hope this helps

LY4SA Depends on conditions where you use it and what frequency. For 2m band you have to be licensed HAM. For PMR I've tested in urban conditions and it is about 2km

LY4SA connector with 3 wires: black - negative, red - power for module, yellow - positive voltage to measure

LY4SA Just checked mine and have not found any CE marking

LY4SA true measured power out is about 7-9W. Battery capacity is very large and enough for a long time, I don't think you need spare batteries, but it's up to you.

LY4SA Try to search headphones for Radtel RT-470. They are twin brothers with 8800

LY4SA Yes, works fine

LY4SA There are no special headphone set for this model, but there are many compatible model from wireless solution to simple headsets and many other compatible with baofeng or Radtel RT-490