KMjolnir t1_iu622cs wrote
Reply to comment by BrokenEye3 in TIL that in 1968 the US Navy proposed turning 2/5ths of Wisconsin into a giant underground radio antenna so orders could still be sent to submarines following a nuclear attack on America by DeadForDecember
Surface vessels would be easier to reach and wouldn't need something that big. Water blocks a lot, and any large surface installation that could reach a sub would be gone. Reaching a nuckear-armed sub, from underground, would require something massive.
voucher420 t1_iu6376h wrote
Like 2/5 of Wisconsin huge?
no_step t1_iu69lmt wrote
It was an ELF, extremely low frequency transmitter. Those radio waves need extremely large antennas and a particular type of soil
[deleted] t1_iu63o89 wrote
[deleted]
TacTurtle t1_iu6bn25 wrote
It is actually more that the wavelength for extremely low frequency radio requires extremely long antennas for efficient transmission and reception - not an electrical hardware size issue.
Wavelength = speed of light / frequency so as frequency goes down, wavelength (and antenna size) go up.
Subs use a long antenna cable they can extend and tow behind underwater for ULF radio transmission and reception.
Faster transmission with a shorter antenna requires getting closer to the surface for higher freq radio which will not penetrate water as easily.
[deleted] t1_iu6c0lc wrote
[deleted]
TacTurtle t1_iu6fhd4 wrote
The actual generation and radio equipment could fit in a couple shipping containers or a small building, it is the antenna that is big.
3MW is small enough power you can get them as pre-packaged skid-mounted units like https://www.westernstatescat.com/power-systems/electric-power/gas-generator-sets/cg260-12-2100kw-3000kw3mw-gas-generator-2/
Example: check out this weather radar array - radar is radio broadcast and receive, just at much higher frequency. WSR-88D weather radars for reference are almost 1MW. The Wisconsin ELF was 2.6Mw.
Viewing a single comment thread. View all comments