I have a question for you about submarine communications. I wasn't a radioman in the Coast Guard, but I remember my ship would communicate with submarines using an ELF (extremely low frequency) radio. Is that still used today? ... and if it is, wouldn't it make sense to add an ELF radio to an aircraft's black box to make it easier to find? I am thinking about Malaysian flight 370 here.
I was a nuclear machinist mate, so my radio knowledge wasn't vast... And while I did have to know something about all of the ship's systems in order to get my dolphins, those dolphins aren't quite as shiny as they once were... :wink:
That said, I know we had a wire that we towed, and if you've seen Crimson Tide, you can see that they're getting some pretty low frequency transmissions at the height of the tension in Control. I don't know if that would be ELF or ULF or what, but yes, you can get one-way transmissions down low. I don't recall being able to transmit on that same frequency. Maybe, maybe not. I don't remember. So there's definitely receive capability - I just don't recall if there's transmit or not.....
I do recall though, that we had to go shallow (PD - periscope depth) to transmit, though, so there's probably no deep-water transmission other than the underwater telephone, which puts audio into the water, and you can literally hear it throughout the ship (but it was quite hard to understand without the handset, IIRC). The reason for needing to go to PD was because you'd have to raise the antenna mast (there were several, IIRC).
Here's a shot that shows at least some of the gear that we could raise, though I don't recall if that was all of it or not.
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