Glenn VK3PE suggests, “For anybody trying to get their uBITX to work in Tx mode. Mine was working then started to become intermittent. I would key the Mic PTT switch and the display shows it’s in Tx mode, but with no power out.
“Tracing signals etc, I found that the K1 changeover relay was not switching 12V to the Tx section. I could hear the relay ‘operate’ but it didn’t actually switch. I replaced the relay and all is fine.”