I believe ELF is more like 100 Hz, which can be received much deeper, so the sub can stay at the bottom. 24kHz is VLF.
Didier KO4BB Magnus Danielson <mag...@rubidium.dyndns.org> wrote: >On 07/16/2012 03:28 AM, Tom Miller wrote: >> I believe they called that system a "bell ringer". It let the sub >know >> that it had to come close to the surface to receive new information. >> I'll need to google around to find more about it. >> >> We had a ELF transmitter (NSS) in Annapolis that transmitted about 1 >MW >> at about 24 kHz. Anyone ever seen 3 inch diameter litz wire? > >We had the ELF transmitter at Grimeton (SAQ) transmitting about 200 kHz > >at 17.2 kHz using the Alexanderson alternator. I think the litz wire >was >4 inch in diameter as I recall it. It was cutting edge in 1924. >It was initially used for telegraph traffic to the US, and the Long >Island main station. It was really never keyed by hand, it was keyed >remote with optical keyer and messages taped back-to-back. After its >main service for telegraph messages was no longer motivate it, it got >used as the "bell ringer" for our subs and kept operational and >maintained up till about 1996 and it has since been taken care off so >it >can be used for museeum. It's now on UNESCOs world-heritage list. > >Links: >http://www.grimetonradio.se/ >http://www.radiostationengrimeton.se/ >http://en.wikipedia.org/wiki/Grimeton_VLF_transmitter >http://www.grimeton.org/ >http://www.alexander.n.se/ > >Do visit Grimeton if you are in south of Sweden. You can also tune in >to >it's transmissions and report back. > >The remaining submarine radiostation in Ruda could actually be turn >into >a time-code transmitter. It's a matter of financing it and giving the >order. > >Cheers, >Magnus > >_______________________________________________ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.