Frank, Coax cable necessary to transmit and receive a radio signal through is subject to compression due to depth. The insulation between the signal wire and the outer shield is usually a foam, as it collapses signal strength will fall off. If shorted, keying the mike on a radio can cause the radio to be destroyed. When I was looking at working with the tourist sub SubCat, one of the problem areas was a surface float for maintaining VHF communications with the surface. It looks like both the hull interface and the antenna cable were under constant need of repair. This sub didn’t even dive very deep. R/Jay -----Original Message----- Frank, > How big and what type of cable would be required to get a voice out of > a submarine. Someone with more electronics experience will hopefully respond, but any communication over a wire (voice or data) has distance limits determined by the type of cable and protocol used. The issue is reflections within the cable over long distances and signal loss. For example, twisted pair network cable has a limit of 100 meters without a switch or router to retransmit network packets. USB cable has a recommended limit of 5 meters without a powered hub to retransmit data. Antenna cable (TV, CB, Marine) is usually recommended to be as short as feasible. Get to 50 feet or so and in-line amplifiers are going to be required for a better signal. |