CQ CQ CQ de BH4FHO.
I have been fixing some radios recently - buying used radios for cheap, fix them up and modify them to transmit in ham bands. When testing them out, I am using my Baofeng DM-1801 HT (with OpenGD77 firmware) as a test target - tune the Baofeng to the same test channel as the DUT radio, and try to call each other.
However, whenever I press the PTT button on either radio, there is is a chance for some very loud acoustic feedback hitting my head with a screech. How to avoid that?