Submerged radio messages

JuanLiquid · 05-17-17, 05:49 AM

Can an uboot in SH3 send/receive radio messages while it's submerged? I think they could do in real life while they were around 20-30m under water, but I'm not sure how SH3 emulates it. Could you confirm?

BigWalleye · 05-17-17, 06:15 AM

Quote:

Originally Posted by JuanLiquid

Can an uboot in SH3 send/receive radio messages while it's submerged? I think they could do in real life while they were around 20-30m under water, but I'm not sure how SH3 emulates it. Could you confirm?

Yes, they could, although probably not as deep as 30m. The closer the sub was to the transmitter, the deeper it could be. Check here:

http://uboat.net/articles/35.html

I recall an active USN officer posting on the SH4 forum that fleet boats could receive radio messages at a depth of about 60 feet. That's consistent and an independent source. Unfortunately, I can't find a link to the post.

bstanko6 · 05-17-17, 08:48 AM

My grandfather was a chief radioman in the USN. he was on the last diesel electric boats. Yes they could at shallow depths. And depending on the sea state. According to him.

JuanLiquid · 05-17-17, 05:05 PM

Thanks for the replies, however I think it's not emulated in SH3, is it?

bstanko6 · 05-17-17, 05:46 PM

You can receive messages at 25m or less, not transmit

jgf · 05-17-17, 06:46 PM

The reception depends on the frequency. VLF (very low frequency, about 100kHz-200kHz) transmissions can travel quite far underwater, though only to a depth of 20-30ft; the USN experimented with this in the thirties, the antennas were hundreds of feet long, suspended on low towers along the coast. Downside is this frequency band is extremely susceptible to noise, especially since they were using amplitude modulation back then. The system is still in limited use today, on a much lower band (https://en.wikipedia.org/wiki/Lualualei_VLF_transmitter).

Video of dedication of USN VLF station in 1953 - http://www.clipxaab.com/NFdvVXZNUy04VDRY

Also, though I've no idea if Uboats used this, some submarines had antennas on buoys that could be released when submerged and reeled back in, allowing both transmission and reception while submerged. A modern variation of this, using satellite relays, is used by nuclear subs today.

https://en.wikipedia.org/wiki/Commun...ith_submarines

CaptBones · 05-19-17, 11:30 AM

Lots of inaccurate info here...

VLF is 3-30kHz, wavelengths from 10-100km. Under ideal conditions, a groundwave could theoretically penetrate to a depth equal to it's wavelength. Practically speaking, reception is reliable down to 40-50m, but because of the "noise" problem, it is only useful for slow data transmission. However, not used in WWII, despite experimentation in the '30s and during the 40's. Came into use by the USN and others during the Cold War.

WWII long distance communications were HF; 3-30mHz (short wave radio, encrypted Morse Code...think "Enigma"), wavelengths 10-100m.

HF reception is very workable at keel depths of 10-30m/30-100ft, using horizontal wire antennas, which you can see installed forward and aft of the conning tower on both U-Boats and US Fleet Boats. Neither used "trailing wire" antennas...impractical for the day. You cannot transmit effectively, or at all for that matter, on a "trailing wire" antenna...it's in the water...grounded. WWII boats could only transmit when surfaced; using either the aforementioned wire antennas or whip antennas, either retractable or mounted fore-aft horizontally (to avoid vibration when submerged). Late in the war, Fleet Boats could transmit at periscope depth with periscope-mounted or mast-mounted antennas, but those were VHF/UHF for "line of sight" tactical voice RT (radio telephone) communications with nearby friendly units.

ELF is used today; 3-30Hz, wavelengths from 10,000-100,000km. Very slow data transmission rate, but very reliable reception at deep depths; let's say that's "in excess of 100m". ELF reception depends on use of long trailing wire antennas. Think amplitude modulation on a radio wave at least 10,000km long! Frequency modulation (single sideband or dual sideband) is just slightly more workable.

Satellite data links use UHF/EHF with buoy-mounted and mast-mounted antennas. But the philosophy is still that submarines are the "Silent Service"...listen but don't transmit unless absolutely necessary.

JuanLiquid · 05-19-17, 04:18 PM

Thank you, I wasn't expecting a deep explanation, I only wanted to know about if my uboot could receive the signal while it's underwater in SH3. I would hate losing any news from a wolfpack while I'm sneaking a convoy.

Good explanations anyway

05-17-17, 05:49 AM	#1
JuanLiquid Machinist's Mate Join Date: Jun 2016 Posts: 130 Downloads: 60 Uploads: 0	Submerged radio messages Can an uboot in SH3 send/receive radio messages while it's submerged? I think they could do in real life while they were around 20-30m under water, but I'm not sure how SH3 emulates it. Could you confirm?

05-17-17, 08:48 AM	#3
bstanko6 Admiral Join Date: Feb 2015 Location: Murwik Naval Academy Posts: 2,122 Downloads: 390 Uploads: 13	My grandfather was a chief radioman in the USN. he was on the last diesel electric boats. Yes they could at shallow depths. And depending on the sea state. According to him. __________________ [SIGPIC][/SIGPIC] BSTANKO6'S SH5 NAVAL ACADEMY http://www.youtube.com/channel/UCPbe...W2NArCA/videos DISCORD https://discord.gg/6tFeTSUmVc

05-17-17, 05:46 PM	#5
bstanko6 Admiral Join Date: Feb 2015 Location: Murwik Naval Academy Posts: 2,122 Downloads: 390 Uploads: 13	You can receive messages at 25m or less, not transmit __________________ [SIGPIC][/SIGPIC] BSTANKO6'S SH5 NAVAL ACADEMY http://www.youtube.com/channel/UCPbe...W2NArCA/videos DISCORD https://discord.gg/6tFeTSUmVc

05-17-17, 05:05 PM	#4
JuanLiquid Machinist's Mate Join Date: Jun 2016 Posts: 130 Downloads: 60 Uploads: 0	Thanks for the replies, however I think it's not emulated in SH3, is it?

05-17-17, 06:46 PM	#6
jgf Watch Join Date: Jan 2012 Posts: 21 Downloads: 26 Uploads: 0	The reception depends on the frequency. VLF (very low frequency, about 100kHz-200kHz) transmissions can travel quite far underwater, though only to a depth of 20-30ft; the USN experimented with this in the thirties, the antennas were hundreds of feet long, suspended on low towers along the coast. Downside is this frequency band is extremely susceptible to noise, especially since they were using amplitude modulation back then. The system is still in limited use today, on a much lower band (https://en.wikipedia.org/wiki/Lualualei_VLF_transmitter). Video of dedication of USN VLF station in 1953 - http://www.clipxaab.com/NFdvVXZNUy04VDRY Also, though I've no idea if Uboats used this, some submarines had antennas on buoys that could be released when submerged and reeled back in, allowing both transmission and reception while submerged. A modern variation of this, using satellite relays, is used by nuclear subs today. https://en.wikipedia.org/wiki/Commun...ith_submarines

05-19-17, 11:30 AM	#7
CaptBones The Old Man Join Date: Nov 2010 Location: Rockton, IL Posts: 274 Downloads: 208 Uploads: 0	Lots of inaccurate info here... VLF is 3-30kHz, wavelengths from 10-100km. Under ideal conditions, a groundwave could theoretically penetrate to a depth equal to it's wavelength. Practically speaking, reception is reliable down to 40-50m, but because of the "noise" problem, it is only useful for slow data transmission. However, not used in WWII, despite experimentation in the '30s and during the 40's. Came into use by the USN and others during the Cold War. WWII long distance communications were HF; 3-30mHz (short wave radio, encrypted Morse Code...think "Enigma"), wavelengths 10-100m. HF reception is very workable at keel depths of 10-30m/30-100ft, using horizontal wire antennas, which you can see installed forward and aft of the conning tower on both U-Boats and US Fleet Boats. Neither used "trailing wire" antennas...impractical for the day. You cannot transmit effectively, or at all for that matter, on a "trailing wire" antenna...it's in the water...grounded. WWII boats could only transmit when surfaced; using either the aforementioned wire antennas or whip antennas, either retractable or mounted fore-aft horizontally (to avoid vibration when submerged). Late in the war, Fleet Boats could transmit at periscope depth with periscope-mounted or mast-mounted antennas, but those were VHF/UHF for "line of sight" tactical voice RT (radio telephone) communications with nearby friendly units. ELF is used today; 3-30Hz, wavelengths from 10,000-100,000km. Very slow data transmission rate, but very reliable reception at deep depths; let's say that's "in excess of 100m". ELF reception depends on use of long trailing wire antennas. Think amplitude modulation on a radio wave at least 10,000km long! Frequency modulation (single sideband or dual sideband) is just slightly more workable. Satellite data links use UHF/EHF with buoy-mounted and mast-mounted antennas. But the philosophy is still that submarines are the "Silent Service"...listen but don't transmit unless absolutely necessary.

05-19-17, 04:18 PM	#8
JuanLiquid Machinist's Mate Join Date: Jun 2016 Posts: 130 Downloads: 60 Uploads: 0	Thank you, I wasn't expecting a deep explanation, I only wanted to know about if my uboot could receive the signal while it's underwater in SH3. I would hate losing any news from a wolfpack while I'm sneaking a convoy. Good explanations anyway