Cave radio book

 

There is no way I would be climbing through narrow, dark, wet tunnels deep underground, but I have always been fascinated by underground communications at VLF and LF. 

As radio waves get attenuated as they travel through water and rock and this attenuation is reduced as the frequency is lowered, cavers tend to use interesting techniques to communicate (and survey) with cavers.

A very interesting book by Mike Bedford G4AEE goes through all the techniques used by cavers. 

Even for somebody like me who (would be too scared!) it make good Christmas reading. The book "Cave Radio" is available from the RSGB bookshop.

Old UK radio and TV clips

If you were young in the UK in the 1950s you may be interested in these two sites dealing with radio and TV in the 1950s. There are many old clips that take you back nearly 60 years.

http://www.whirligig-tv.co.uk/radio/index.htm  
http://www.whirligig-tv.co.uk/

   

Sub-9kHz induction comms resource

John F5VLF/G3PAI has brought a very useful website about induction mode communications below 9kHz to my attention. This site is mainly about cave location and beaconing systems, but there are some neat schematics for local coverage (thousands of feet range) TX and RX circuits that would be suitable for QRSS and similar experiments in the "Dreamers Band" as some have called it. See http://radiolocation.tripod.com/