Retevis RB639 - Overview, on air test and programming demonstration

It's another PMR446 radio, or two to be precise as they're sold as a pair, the Retevis RB639, some of the most basic PMR446 radios you can buy and probably a little quirky as well. Firstly, these have a permanently fitted rechargeable battery, you can't remove it unless you're tech savvy, it also ships with some default CTCSS and DCS settings across the 16 PMR446 channels which means it will not work with other radios out of the box and the settings have to be changed in the programming software, which I demonstrate in the video. I suspect it's 3-star average review on Amazon is down to people simply not knowing the CTCSS/DCS settings are enabled and do not match the radio they already have. It doesn't have a standard volume control as per most PMR446 radios, the up/down buttons on the side are in fact for channel change or turning the VOX on or off as supplied from the factory, writing the radio with the programming software enables the extra menu functions, volume settings are set via the power button on the top, brief pressing it turns up the volume or down to zero if already at the max level, which is 3. On air it sounds ok, my examples both appeared a little high on frequency so when the SDR was tuned to the PMR446 channel as expected it sounded awful, this didn't appear to be an issue with the SDR as the frequency didn't drift as it warmed up and the H777 I tested in the previous video weren't adrift, it wasn't to the point of illegal and it will probably come down as it was high, but only in the factor of hundreds of Hz, probably around 600Hz max but enough to sound terrible on the SDR so I tuned the SDR to compensate. The on air test was done with the same arrangement as the H777 was tested with, so I will be looking to redo the tests on these again later maybe with a better antenna, but again range was similar as the H777 Programming at time of recording has to be done with Retevis' own software, there is no support in CHIRP for these right now, nor the related RB39 which is the FRS version for the American and Canadian markets, the software is available on Retevis' website, the software for these is the one without the "P" designation. These radios charge using USB-C (probably not with an intelligent charger, only a dumb charger) and the set comes with a suitable cable that allows both radios to charge together, their design however does hint at a drop-in charger option possibly being available as an aftermarket accessory. At time of filming these are £11.99 from Amazon and you can get them here: https://amzn.eu/d/06HQTKt2 #hamradio #pmr446 #retevis Help support the channel, basic level for only £0.99 or early access for an extra £2.00:    / @paulmcgeem0wnu