Not directly relevant, given its size, but interesting for comparison
purposes.
************************************************************
ELF, VLF and LF radiation from a very large loop antenna with a
mountain core
Author: Barr, R. Ireland, W. Smith, M.J.
Nat. Inst. of Water & Atmos. Res., Lower Hutt ;
IEE Proceedings, Part H - Microwaves, Antennas and Propagation (ISSN
0950-107X), vol. 140, no. 2, p. 129-134.
Abstract: Abstract The establishment of an LF/VLF/ELF transmitting
facility at the Homer tunnel near Milford South in the South Island of
New Zealand is described. The antenna consisted of a 3.3 km-long
PVC-covered aluminium conductor passing through the tunnel and over
the mountain above, forming a large vertical loop antenna.
Measurements of the electric field radiated from the transmitter,
recorded at both Lauder and Palmerston, 133 and 225 km from the
transmitter site, respectively, are presented. The antenna radiation
pattern derived from observations made onboard an Orion aircraft
circling the antenna at a distance of 200 km is also presented.
Theoretical models are derived which enable fits to the radiated field
data to be made over a wide frequency range (0.5-40 kHz). With 1 kW of
input power the antenna produced peak radiated fields at frequencies
near 10 kHz equivalent to those of a vertical monopole source
radiating 150 mW.
****************************************************************
I have a hard copy of this article somewhere but cant find it at
present. The reference should be enough to find it in a university
library. Publication date was circa 1993, IIRC.
73
DaveB, NZ
ZL3FJ
----- Original Message -----
From: "Roger Lapthorn" <[email protected]>
To: <[email protected]>
Sent: Sunday, June 27, 2010 7:52 PM
Subject: Re: LF: VLF earth antenna article in wiki
I agree about the Wiki antenna: it is strung between the mountains,
not
using buried electrodes.
Maybe we dreamers need to consult some textbooks on ELF/VLF antennas?
Another data source should be any publicly available papers about
Project
Sanguine antennas. IEEE Antennas and Propagation may have had some
references in the 1970s or 80s?
- Military Communications: From Ancient Times to the 21st
Century<http://www.amazon.co.uk/gp/product/1851097325/ref=sib_rdr_dp>talks
about the Wisconsin Project Sanguine antennas being 14 miles long and
mounted on 40 foot poles. This was for 76Hz. These were in some
sort of
array and connected by 165 miles of cable (this info can be read in
the book
extract on Amazon!).
- ELF Communications
Antennas<http://www.amazon.co.uk/Elf-Communications-Antennas-Electromagnetic-Waves/dp/0906048001/ref=sr_1_23?ie=UTF8&s=books&qid=1277624698&sr=1-23>by
Burrows is an IEE publication that must contain some useful
information.
Unfortunately these can be expensive to buy but I may be able to read
copies
at the University Library here in Cambridge. Usually such texts are
highly
mathematical whereas what I need is a good overview which could be
easily
grasped without too much maths.
73s
Roger G3XBM
2010/6/26 Stefan Schäfer <[email protected]>
Hi Roger, VLF,
Today Markus gave me the hint of an (at least for me) most
interesting
article in wikipedia. It is about a "earth" antenna like we have it
in
principle and it shows that it can indeed compete with a traditional
marconi
antenna. Maybe you know that since 10s of years but for me it was
new:
http://en.wikipedia.org/wiki/Herzogstand_Radio_Station
or in german
http://de.wikipedia.org/wiki/Funkstation_am_Herzogstand (more
detailed and
with a picture of the antenna construction)
73, Stefan/DK7FC
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
G3XBM GQRP 1678 ISWL G11088
|
