Warning: I swore off hot mic checks on the ramp until that Tuesday in Amarillo
For 6 years I skipped the mic check on the VHF radios because I figured if the squelch opened, it worked. Last Tuesday at the Amarillo ramp it was 104 degrees and we were rushing a turn, and the FO keyed up to get our clearance and got nothing but dead air, over and over. I pulled the radio, checked the antenna, checked the coax, all clean, then finally swapped the mic itself, and the old one had an intermittent PTT switch that only failed when the cockpit got hot. We burned 40 minutes and pushed 22 late because of a part I could have flagged with a 10 second check before we ever left the gate. Now I key every mic on the preflight, hot or cold, and I write down which ones sound scratchy. Any of you got a quick way to test a PTT without dragging the whole rack out?