Low Frequency Radio and subs

[jverity at mindspring.com]

today's submarines are equipped to receive ultra-VLF signals -- around 100 
Hz, I believe (that's plain old Hertz, not mega or kiloHertz) -- transmitted to 
them from a giant, miles-long Navy antenna complex located in upper 
Michigan. i think the transmitter involved puts out somewhere around 1 million 
watts, maybe more. (local residents, i recall, have been upset about potential 
harm from these transmissions.)

these ultra low frequency waves are able to reach subs deep beneath the 
sea. I don't know what kind of antennas the subs use, but probably a long 
wire trailed behind them. as i understand it, the subs listen for regularly 
broadcast signals that, in so many dots and dashes, say "ALL IS OK." If, 
however, these signals do not come in as scheduled, the subs have orders to 
assume that all-out thermonuclear war has broken loose, a la 
Strangelove--that the Big One has begun and Michigan is dust and that the 
best thing to do is head for some pre-determined location and launch all 
missiles. 

one technical problem with such a setup is that the transmitter has a 
exceedingly low bit rate, because it takes so long for this monstrous exciter 
and power amp to reach full output with each press of the code key. huge 
coils and massive vacuum tubes must be energized for each dot or dash. i 
believe we're talking seconds per bit, not vice-versa. so the amount of 
"information" that can be sent is very low -- enough, tho, to indicate OK or 
NOT OK. we do, indeed, live in a digital world. 

i think our subs also get signals from laser-equipped satellites, which use a 
(reddish?) light color that can penetrate fairly deep into the sea. 

JV