Metal detecting: all you need to know to get started

248 Pages·2013·8.68 MB·English

by  Crisp

Acknowledgements
I would like to thank and acknowledge all the help I have been given over the
last two years. Two people especially have helped enormously with this book.
The first is Tony whose idea this book was and his input, particularly into the
finds chapter which was enormous, as was his help with the overall style
throughout the book.
The second is Micky who must also be mentioned. Her sketches, illustrations
and line drawings of finds are first class and provide the informal and amusing
flair that I was looking for. Also for her input into the proof reading -she
managed to correct my writing into readable English!
There are a few others like Sam at the British Museum; Nigel and Gordon
from our club who read the proofs, and corrected any slip-ups. Any mistakes that
are still there are mine completely. If you find any, please feel free to let us
know so we can correct them on the first reprint.
I would also like to acknowledge and thank the following photographers for
the use of their photographs.
The Trustees of the British Museum and the Portable Antiquities Scheme
(PAS).
Mike Hogan, who provided one of the photos of the Frome coins, and the
one of Dr. Alice Roberts and me.
Steve Minnitt, the director of Somerset Museum service who kindly
provided the Frome hoard display layout in the Taunton Museum.
Neil, a Somerset farmer, who provided a photo of himself and his cows.
Dave Crisp 2012
Editor
Greg Payne
Design Editor & Origination
Christine Jennett
Published by
Greenlight Publishing
The Publishing House, 119 Newland Street,
Witham, Essex CM8 1WF
Tel: [phone]
[email protected]
www.greenlightpublishing.co.uk
ISBN 978 1 897738 47 4 (Print)
ISBN 978 1 897738 48 1 (ePub)
ISBN 978 1 897738 4 9 8 (Mobi) eBook conversion by Vivlia Limited.
© 2012 Dave Crisp
All rights reserved.
No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by
any means, electronic, mechanical photocopying, recording or otherwise, without the prior permission of
Greenlight Publishing.
Contents
Introduction
1 Brief History of Metal Detectors and Our Hobby
2 Equipment
3 Starter Detectors On Test
4 Organisations, Clubs and Dealers
5 Where To Search and Ten Ways To Gain Permission
6 The Dangers of the Farm
7 Detecting Land
8 How To Detect
9 What You Can Find – Coins
10 What You Can Find – Artefacts
11 Portable Antiquities and Treasure
12 Cleaning, Conserving and Researching Finds
13 Upgrading to a More Expensive Machine
14 Not One Hoard, But Two!
Appendices
1 The Treasure Act
2 The National Council for Metal Detecting
3 Further Reading
4 Useful Contacts
5 Grid References
Introduction
M y detecting partner Tony and I both started from scratch with no
knowledge of metal detecting whatsoever. But between us we now have
over 25 years’ of experience.
It was in July 2010, after I had found the Frome Hoard of Roman coins, that
Tony realised that there was limited information (in terms of books) for
newcomers to the hobby to buy that would tell them what they needed to know.
So he put it to me that we could put together an essential book on metal
detecting, with all the relevant information, including the Portable Antiquities
Scheme (PAS) and the1996 Treasure Act. This would also give me an
opportunity to tell my story as finder of the Frome Hoard.
Dave Crisp
Dave Crisp
We are sure that you will find in this book the knowledge that you need to
start the hobby correctly. Also covered is where to go, and how to use your
detector. You will also see a selection of finds to help on initial identification of
the objects you recover. There is a section on the 1996 Treasure Act and the
Portable Antiquities Scheme where, through your local Finds Liaison Officers
(FLOs), you can get help with the identification of finds. We have tried to make
this a light-hearted look at our hobby and how to go about it, but with a look at
the serious side of doing things correctly.
Throughout this book we have tried to emphasise the benefits of cooperation
between museums, the archaeologists involved in the Portable Antiquities
Scheme and detectorists.
We have also been very lucky to have comments and contributions from
academics such as Roger Bland (head of PAS at the British Museum); Steve
Minnet (Head of Somerset’s Museum Service), and Katie Hinds (the FLO for
Wiltshire). We are also indebted to Pippa Pearce for help on the conservation of
finds, and Sam Moor-head (Iron Age and Roman Finds Advisor at the British
Museum). Good luck and good detecting - Dave Crisp
Brief History of Metal Detectors and Our
Hobby
What is a Metal Detector?
A metal detector emits an electromagnetic field from its search coil. When a
metal object enters this field it causes a change or distortion. This is relayed to
the control box, which analyses the response and provides a sound in the
operator’s headphones and, on some models, a display on a screen. The strength
and type of the signal can also tell the detector how deep the item is, and the type
of metal it is made from. This information can also be displayed on some
detectors.
Second World War, 1942, mine detector.
One of the first detectors was built by an engineer by the name of Gerhard
Fisher. In the late 1920s he was working on radio direction finding equipment
for aircraft and found that metal ore in the ground, or metal roofs on buildings,
affected the system. From this early beginning he designed a metal detector, for
which he received a patent in 1937. These very early machines were also used
by geologists, gas and electricity companies, and the police. During the Second
World War and afterwards they also helped to clear enemy mine fields. These
early mine detectors were heavy and used a lot of power, but they were the
cutting edge of technology at the time.
Lt. Jozef Kozacki designed the first practical electronic mine detector, called
the “Mine Detector Polish Mark 1”. It was soon improved upon and mass
produced. Some 500 were issued to the British Army in time for use prior to the
Battle of El Alamein in October 1942. An example is shown here (reproduced
with permission). It looks quite familiar to a 21st century detectorist!
After the war these very early machines were used at the very start of our
hobby, although in those days you needed a partner just to carry the battery
pack! It was in the 1950s and 1960s, with the invention of the transistor, that
detectors transformed into lighter machines which used batteries that could be
fitted integrally. In America, Charles Garrett obtained a patent for a “Beat
Frequency Oscillator” type metal detector and this is when the hobby really
started up, with more and more manufacturers coming into the market. Garrett
was joined in the 1960s by other now well-known names such as White’s and
Fisher.
Shown above right is the first detector I ever purchased in the late 1960s. As
you can see, it’s just a hoop on a stick with an adapted transistor radio; but it still
works (after a fashion!). It is tuned by using the slider on the main stem. I was
assured, by the shop assistant that I would find lots of things with it! After a
couple of outings in the garden it went into the cupboard, and has seen many
more cupboards since then. I now bring it out as a curiosity when giving talks!
My first BFO metal detector from the late 1960s.
Tesoro, who started in the late 70s, became one of the early makers of a full
range of machines. One of these models was the legendary, Silver Sabre,
renowned for its ability to find small hammered coins. Tesoro, which is Spanish
for treasure, are still going and I still use my Laser B1 as a backup machine.
Great strides at that time were also being made in improving coil design,
important for depth and signal recognition. Induction Balance machines gave the
opportunity to discriminate between metals and ignore the targets you did not
want (iron). So with the ability to read the type of metal found, machines were
getting more sophisticated. Also, with further improvements in discrimination,
they were going forward in leaps and bounds.
One of the main bugbears of the early detectors was the effect on them of
minerals in the ground. Reducing the effects of this mineralisation was one of
the next big advances. However, manufacturers had to be careful in the design of
this “ground balance” as some metals give similar readings to ground minerals,
and if the facility is wrongly set some desirable objects could be lost and the
detector suffer from loss of sensitivity.
Many new designs of coils came out in the mid to late 1970s, and this led to
the development of “motion detectors”. With these, by keeping the coil moving,
the detector could discriminate and at the same time auto tune out the effects of
ground mineralisation. By the 1980s and 1990s computer technology was
incorporated into detector design, and this had a fantastic effect on the models
available.
My Minelab Explorer II detector and the Roman hoard I found with it.
So we move into the late 1990s and the 21st century. What fantastic advances
there were! Technology was advancing very quickly and giving us machines that
were never dreamt of years ago. Many of the old names - such as Garrett,
White’s, Fisher, and Tesoro - are still producing excellent machines. However,
they have been joined by others - notably Minelab that started in 1985 but now,