----- Original Message -----
From: "Andrew Talbot" <[email protected]>
To: <[email protected]>
Sent: Tuesday, July 17, 2001 2:51 PM
Subject: LF: ELF Antennas - ground loops tested.
Presumably other ideas for antennas were also tried back then.
Some years ago, with permission from the railway company concerned, some
tests were done in Wansford Tunnel on the Nene Valley Railway. The tunnel is
550 metres long and straight, 7 metres high and 7.5 metres wide. It runs
through oolitic limestone and is lined with Victorian brick. It contains two
standard gauge railway tracks, one of which runs only about 150 metres into
the tunnel and is used in winter to store rolling stock in the dry.
John Hey's cave radios on 87 kHz worked well from one end of the tunnel to
the other, using loop aerials. It made no difference whether the loops were
placed between the running rails or at the side of the tunnel, or in the 6
foot space between the two tracks.
A full write-up appeared in:
Rabson, John (1998), Underground Radio Tests on the Nene Valley Railway,
CREGJ 32, p27, Jun 98.
If anyone would like to know more about these tests, I would be happy to
talk to them on 01394 460298 or via email, [email protected].
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