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ORLDenver 17/10/2020
I now have 3 of these little jewels. Easy to carry around. Easy to use, once programmed. Also known as 9100 to find programming software. This one came with usb cable & disk. Don't try a standard headset, won't work. Use the supplied earphone. The tiny coil antenna is pretty useless, though it is resonant at 440 MHz. I made 2 real antennas. UHF only is 4.4" of copper foil applied to a small paint brush handle. Very broadband. VHF/UHF is 3.5" of copper foil around a 1/4" paint brush handle with approx 32" of awg 30 enameled wire coiled around the upper half (2.3"). The copper wire from the bottom of the antenna to circuit board is part of the overall length. Tune using a nanovna, cut & try until resonant on both bands. UHF is good 410 to 500 MHz. VHF is narrow & a chore to tune it. I dipped both antennas in Plasti-dip several times. The coating decreases the resonant frequency, so tune it about 10 MHz higher before dipping. I can use mostly repeaters that aren't too far away on both bands. I measured the RF power out set to high, not 1 Watt, but I got 0.3 Watt, both VHF & UHF. On low, too low to read on my meter, under 0.1 Watt. It has a 2 stage RF PA & plenty of LP filtering to cut harmonics. To mount the antennas, drill a hole in the end of the plastic antenna cover. Start with 1/8" bit & work it up to 1/4" while holding it tightly. Sound quality is good on both transmit & receive once you install a 15 ohm resistor in series with the speaker & turn off the voice. To get better modulation, drill a 0.2" hole over the mic. Battery is good for many hours, uses about 100 mA on receive. Charge needs about 350 mA @ 5 VDC. The battery indicator (upper right) works when charging & radio off. It's heart is an AT 1846s transceiver on a chip, look it up & read about this chip, it's pretty amazing. Data sheet says it works on the 222 MHz band. I haven't tried it, but will soon. The tiny pot, bottom right trims the frequency. It is extremely sensitive, be careful.
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ORLDenver BAOFENG T1 USB Programming Cable Mini Walkie Talkie Write Frequency Line Software is Chinese, try Chirp.

mike mccrann 05/05/2020
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