The Collins radio that taught me to trust my ears over my scope

Back in 2008 I was working a line maintenance gig at a small regional airport in Ohio. We had this old Gulfstream that kept throwing a flag on the Collins comm unit during preflight. My lead tech told me to pull out the scope and check the waveform, which I did for like two hours. Nothing looked wrong on the screen but the thing still wouldn't key up right. Finally the hangar manager came over, an old Navy guy named Tom, and said have you even listened to it yet. I plugged in a headset and sure enough the squelch was crackling something nasty. He showed me a pot adjustment that wasn't in the manual and it fixed it in five minutes. These days with all the digital avionics I hardly ever just sit and listen anymore. Has anyone else had an old timer show them a trick that their training completely skipped over?

2 comments

2 Comments

paul11713d ago

The squelch adjustment trick is a good one, but I have to point out something about that Collins comm unit. The older ones like the 618M series actually had a specific test point in the manual for setting the squelch threshold, it wasn't entirely undocumented. Tom probably just knew where to turn the pot blind because he had done it a hundred times. Modern digital radios are a different animal though, you are right about that. Sometimes a little analog troubleshooting still pays off when the black boxes get fussy.

dylanward13d ago

Wait, they actually had a documented test point in the manual for that? I always thought it was just some old timer trick passed down, not an actual official spec. That kinda blows my mind honestly.