![]() |
Quote:
It also applies ETR3(SS). Your expertise is valued, but saying "Look at my sig" says you're trying to win an argument by simply saying "I know more than you, so there!" Better to show that you are right, rather than just saying so. This is my opinion, but it is also the moderator saying let's keep it calm please. |
J0313, your statements caught my attention, because I have researched the question of whether a WW2 US fleet boat could transmit when not fully surfaced and not found conclusive evidence that they could.
Quote:
Straub's site does not address radio transmission while at radar depth. It only makes a distinction between surfaced and submerged. I am unable to find any support for your statement that "they could transmit and recieve at radar depth" on Straub's site. Straub does have a link to the external diagram of a fleet sub at the HSNA site: http://www.hnsa.org/doc/fleetsub/app...es/figa-02.htm This diagram identifies the radio antennas as one long-wire antennas running forward from the shears and two others from either side of the conning tower coaming. Portions of these might be out of the water when the boat was at radar depth, but the end of the long wire closest to the deck stanchion might well not be. It's hard to see how any of these antennas could be energized with transmitter voltages when not completely surfaced. Even when surfaced, it would seem that heavy seas might ground them out. I have wondered about the possibility of transmitting from a sub which was not fully surfaced. The first-person accounts only refer to transmitting while "surfaced" but that is negative evidence, as is the evidence of Straub's site. The HSNA diagram infers that WW2 US fleet subs were not equipped to transmit unless fully surfaced, but certainly doesn't prove it. You state pretty strongly that it was possible. Could you provide me with your sources for this? |
SH3 allows u-boats to recieve messages at depths up to 25 meters (80 feet), but send only on the surface. At the time the developers said that their information said that was possible. I don't know, but if it was possible for u-boats I don't know why it wouldn't be for fleet boats.
|
Steve, I don't recall ever seeing any indication that US fleet boats could (or did) receive radio messages when as deep as 80 feet. And I believe u-boats did so, routinely. I suspect this may have been a result of the fact that the fleet boats operated at much greater distances from base. Pushing a radio signal through water takes a lot of power. Power falls off with the square of the distance from the transmitter. Double the distance and you get only one-quarter of the power. So getting a message to a sub 4000 miles from home would take four times as much power as would be needed to send the same message to a sub 2000 miles away. Another way of looking at it is that the farther sub would have to be a lot closer to the surface to receive the message. Which seems to match the first-person reports of American subs usually getting messages when at or near periscope depth and the German subs receiving messages when much deeper.
|
On Radio Transmitting
I've been doing quite a bit of research on this topic today, and am unable to find anything that suggests that US Fleet Type submarines were capable of transmitting radio signals in any condition other than surfaced [edit] with the exception that later in the war VHF transceivers were installed and the antenna for these was mounted atop the periscope shears. Here's an excerpt from a webpage decribing the radio gear and antenna array on the USS Pampanito:
All of the original radio equipment is in working order. The transmitter is a TBL-7 with coverage on 175-600 kHz and 2.0-18.1 MHz. The transmitter is capable of 50 watts on AM phone, and 200 watts on CW. RAL and RAK receivers can still hear signals, sometimes better than modern receivers. Three long wire antennas are mounted on the port side of the conning tower, running aft to a stanchion near the stern. The original transmitter has been used on many occasions for QSOs and contesting on the amateur bands. With the long wire antenna mounted 20 feet above the salt water of San Francisco bay, signal reports are surprisingly good. The salt water acts as an excellent ground plane, and most stations are very impressed with the signal. This antenna arrangment is very similar to that described by the radioman who wrote the article referenced by J0313, with the exception of his description of an antenna mounted on the periscope shears. Additionally, all shipboard radio transmitting antennas of this era that I have found were long wire dipole antenna assemblies. The long wires you see running from superstructure to masts and then down again to anchoring points at other places on the upper works of surface ships and submarines are exactly this: dipole antenna arrays. Such dipole assemblies were designed to the standard required for half-wavelength antennas, which explains why they were so long. Much more information on this type of antenna can be found here: http://www.hnsa.org/doc/radio/chap20.htm Given the antenna assemblies in use, their required length, and the fact that the mounting arrangment on Fleet Type boats required at least one end of the antennas to be mounted to a stanchion on the deck, either fore or aft, drives to the obvious conlusion that it was impossible to get the antenna entirely clear of the water without surfacing the boat. Finally, in Chapter 20 of the Fleet Type Submarine manual, page 197, the following prodecure in preparation for a dive is described for the Radio Room: M. Radio room. 1. Disconnect the antenna lead and shut the trunk flapper. Also, given the description of his duties reported by the radioman in the article referenced by J0313, in which the writer states that while submerged his duty station was on the sonar set, and only upon surfacing would he report to the radio room, it seems very clear that WW II US Fleet boats were NOT capable of radio transmission other than while surfaced. |
Quote:
|
|
Quote:
|
VHF
If you do some research into VHF, and its application during the war, you will notice two things. It is capable only of line of sight reception and transmission, meaning that is a relatively short range method of communication. This limitation on VHF still exists today. Also the following procedural guidelines were in place regarding communications using VHF:
5305. Very-high-frequency (VHF) tactical radiotelephone circuits have proved their value in war. The following general rules are set forth for the guidance of responsible commanders in the use of such circuits in wartime: a. They may be used for initial contact reports, emergency maneuvers, and the transmission of important information when visual means are prohibited or too slow. b. Only a minimum of transmission should be permitted during darkness or reduced visibility. c. Caution must be exercised in the use of plain language transmissions of vital importance which would be of value to the enemy if intercepted. 5306. Detailed instructions supplementing or modifying the foregoing general principles shall be issued by responsible commanders as appropriate and necessary, depending on the situation existing. Note that under conditions of darkness or reduced visibility, when submarines or other vessels might be within range without being detected, use of VHF radio was discouraged.-RF The above referenced procedural statment can be found here: http://www.virhistory.com/navy/flory/id11.html |
From the Straub website (http://www.ka8vit.com/subops/subop1.htm):
"VHF TRANSCEIVERS: Later on in WWII SCR522 and SCR624 VHF transceivers were added to the Radio Room. These were multi channel crystal controlled transceivers used primarily to communicate with aircraft, particularly during Life Guard operations." Redmane, this seems consistent with your observation that VHF is (and was) only useful for LOS. Quote:
BTW, the diagram at HNSA is of a Balao, IIRC. The Balao class was the standard US fleet boat at the end of the war, and didn't enter service until mid-43. |
Quote:
|
I guess this will never be solved. There arent any first person accounts that I can find. So I will continue looking but its probably going to be fuitless.
|
And besides this whole thing took off when ERS3 made his comment about not having an antenna out of the water when submerged. Well it sure looks like there is a few out of the water at radar depth. Granted VHF was only for LOS. As far as ranges go. I havent been able to find anything on what the ranges for those sets are. But I am going to keep looking.
|
Don't feel too bad
Ultimately, you are not wrong in asserting that a US Fleet Type boat could both transmit and receive at radar depth. The only provisos are that they would have to have a VHF rig, and the communication would be limited to the capabilities of that gear. In other words, Fleet units close enough to receive the signal could do so, but by no means would it be possible for the boat to contact a ground station on this gear unless in range, not blocked by any interference, and the ground station would also need to have the appropriate gear. Additionally, I make this observation: I have been at radar depth on approach to a target in high sea states, had the periscope raised just enough to clear the housing, and had it be regularly washed by the wave action. So there also would be that factor of limitiation on the VHF.
[EDIT] Found this on Wiki regarding standard range of VHF transmissions: http://en.wikipedia.org/wiki/Very_high_frequency |
Quote:
|
All times are GMT -5. The time now is 01:12 AM. |
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright © 1995- 2025 Subsim®
"Subsim" is a registered trademark, all rights reserved.