Originally Posted by spikedrivingblues
It does. Now that you mention it, it reminds me of the beeping on that old TV show "Emergency" when they got a call.
Is that something that would be heard over train crew chatter?
Sorry for the delay in response. I don't get in here as often as I'd like.
Yes. Any where you have a large fleet, two or three tone signalling was handy to keep from hearing calls that don't pertain to you. Only calls with your correct sequence of tones would open up your receiver. You heard nothing if the call was for someone else. Today's radio systems handle it silently, and digitally. And quicker.