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ETR3(SS) · 05-08-21, 10:51 AM

I've changed it...somehow. All I can remember is that it is not something simple or obvious.

As for the radio side of things, this is where my experience comes in. Fleet boats had the following receiving radio sets:

RAK-6: This set covers the VLF, LF, and MF radio bands from 15 kHz to 600 kHz

RAL-6: This set covers the MF and HF radio bands from 300 kHz to 23 mHz

RBH-2: This set covers the MF and HF radio bands in frequencies from 300 kHz to 1.2 mHz and 1.7 mHz to 16 mHz.

The lower frequencies (VLF,LF) would be data only in the form of morse code, while the higher frequencies (MF,HF) would be voice circuits. As such receiving radio signals while submerged would only be possible on lower frequencies, with VLF being the best being able to penetrate to a depth of 40m or 131ft.

Now the transmit side of things:

TBL-5/6/7: Can transmit voice (75kHz-600kHz, 2mhz-18mHz) and data (175kHz-600kHz, 2mHz-18mHz) in the LF, MF, and HF ranges.

And the final puzzle piece, the antenna:

Note the Transmit Antenna and the separate Receive Antenna. In order to transmit and be received, that antenna needs to be out of the water. There are of course other antennas onboard but those are for LOS comms, basically short range.

05-08-21, 10:51 AM	#4
ETR3(SS) Ocean Warrior Join Date: Dec 2007 Location: Between test depth and periscope depth Posts: 3,021 Downloads: 175 Uploads: 16	I've changed it...somehow. All I can remember is that it is not something simple or obvious. As for the radio side of things, this is where my experience comes in. Fleet boats had the following receiving radio sets: RAK-6: This set covers the VLF, LF, and MF radio bands from 15 kHz to 600 kHz RAL-6: This set covers the MF and HF radio bands from 300 kHz to 23 mHz RBH-2: This set covers the MF and HF radio bands in frequencies from 300 kHz to 1.2 mHz and 1.7 mHz to 16 mHz. The lower frequencies (VLF,LF) would be data only in the form of morse code, while the higher frequencies (MF,HF) would be voice circuits. As such receiving radio signals while submerged would only be possible on lower frequencies, with VLF being the best being able to penetrate to a depth of 40m or 131ft. Now the transmit side of things: TBL-5/6/7: Can transmit voice (75kHz-600kHz, 2mhz-18mHz) and data (175kHz-600kHz, 2mHz-18mHz) in the LF, MF, and HF ranges. And the final puzzle piece, the antenna: Note the Transmit Antenna and the separate Receive Antenna. In order to transmit and be received, that antenna needs to be out of the water. There are of course other antennas onboard but those are for LOS comms, basically short range. __________________ USS Kentucky SSBN 737 (G) Comms Div 2003-2006 Qualified 19 November 03 Yes I was really on a submarine.