Quote:
Originally Posted by J0313
Thank you for this info. I have a question. Could it be done in calm sea's?
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Could what be done...tactical voice communications while at PD/RD, or HF transmissions?
A "qualified" yes for both, actually. As you have found, by late '43 there were tactical voice VHF and UHF antennas that were useable at periscope depth/radar depth. But calm, or at least "low" sea states were necessary (they can't transmit when under water, even just temporarily). Except for unusual circumstances (or unique designs today), VHF and UHF are
USUALLY line-of-sight. For all practical purposes, you had to have the station you wanted to talk to in sight and the distance to the horizon for a sub at PD ain't very far...and it's not much farther when you're surfaced either! Although, before Secure Voice equipment became common in the '70s, the biggest COMINT security concern was people jabbering away on tactical circuits with the misperception that you absolutely
couldn't be heard "over the horizon"...tain't so.
So, for submarines, the tactical communication sets were most handy for talking to aircraft; "line of sight" to an A/C at 20,000-30,000 ft or even 10,000 ft, is a lot farther than you can actually "see". The other welcome use of those tactical voice sets in US submarines came later in the war, when we started forming "Wolfpacks" in October '43. You should also note that the antennas you see in photos, most often mounted high on the shears or in a periscope/snorkel head are the ESM and IFF antennas, receiving units only...it's nice to know before you surface, if somebody up there is sweeping or has locked-on to you and whether or not it's a "friendly."
Also by late war, several types of whip antennas with tunable VSWR antenna couplers were developed for HF use in submarines. In some photos they can be seen at the aft end of the shears or on a stub mast on the cigarette deck, in both raised and lowered positions. They didn't retract vertically, they had motor operated geared trunnions to lower them to a horizontal "trailing" position when submerged. Again, the sea state would generally determine whether or not you could transmit (receiving is easier, the antenna isn't "hot", you're not trying to push electromagnetic energy out into the "ether", just trying to collect a few stray electrons here or there, riding their wave). Practicality would again dictate the purposes to which you would put that equipment. It wasn't usually suitable for the long-haul HF transmissions (especially at PD/RD), but was used for tactical medium range communications in the low-HF/high-MF band (frequencies assigned usually between 2200-2800KHZ). Again, good for keeping the "Wolfpack" spread out searching for targets and calling them together when one (target) is found.
I suppose that's some more of the "long way around" to an answer, but I hope it helps (and everybody can calm down again).
