I had this problem with the Btech PC03 programming cable when I used it with my Retevis RB26 GMRS. We live in 2-story home and my two children live upstairs. My wife or I had to yell pretty loud for them to hear us sometimes, so I purchase a 5-unit Retevis RB26 package from Amazon to use as an intercom system. They work great! Three radios are in the bedrooms with other two in her kitchen and my office. I used Chirp to program the key lock function on the PF1 key. It came programmed for monitoring. My kids would sometimes hit the PF1 or 2 keys instead of the PTT key and change the channel. The only bad thing is it will return to unlocked if powered off, but I just have to press the PF1 for a couple of seconds to lock the keys again.
