Originally Posted by Altimeters
If we were to have the same frequency on both we would get that echo. Much the same that Morno has been talking about. However I'm starting to just turn down the audio on comm 2 below 10,000. I'll see if I can make it changed in the book when I talk to the CP.
Are you sure you'd have "that echo"? Have you actually tried it for a ground/tower/approach frequency? If comm 2 is picking up your transmission on comm 1 it's going to take a tiny fraction of a second come back at you. It's all happening at the speed of light and the distance the signal has to travel is measured in metres. Perhaps you've had a bad experience with Centre frequencies. I've had to monitor two adjacent yet combined Centre frequencies and you'd get an echo with your transmission because it was being re-broadcast on the other Centre frequency with some delay. This doesn't happen when using both radios for the same frequency though, at least not in the type I fly.
On the subject of making mistakes. Yes we all make mistakes sometimes and I'd never have a go at someone who accidentally transmits on 121.5 once a year, however you occasionally come across an individual who repeatedly makes these sorts of mistakes over and over again. I'd estimate that in the mob I work for, at my base, 95% of these errors are probably made by one person. Of the other 5%, 4% are made by slightly stressed new employees undergoing line training, and the last 1% is from normally professional guys and gals making their once-a-year cock-up.