Bob Bob wrote:
Hi Eric

First thought is that I have read somewhere about underwater antennas.
They were a lot shorter than what you have in air and the attenuation
was much worse. Might be worth some research. If you (say) ran a couple
of hundred kilohertz you could FSK or PSK that at some low data rate.
Perhaps even drive it with one of the older 1200/75/300 modem chips. (ie
RS232 serial data) I mean this is how the US subs get their action
messages (although this is a really low data rate)

Apologies for the waffling

Cheers Bob Vk2YQA


Bob,
I suspect if he wants to go wireless, he is going to have to go further
down the RF Spectrum than a couple of hundred khz, even for that short a
distance. The OTS comm systems for their full face masks have a range
just slightly over what he desires, operate around 30 khz SSB. At that
frequency, he is not going to be able to move a great deal of data very
fast but as I recall, that was not a factor. I use an Aladin AirZ
hoseless computer and I think the transmitter operates around that same
frequency range.

Nice to see folks from "VK" land here with us.

73 OM
Andy
WD4KDN