D is for... Detector, (Mine Detector 4C).

(c)2009 Sarah B / Planet-Tharg
Manufactured by United Scientific Instruments, Coventry, UK. The Mine Detector 4C has been the standard mine
detector of the British Army, and many other countries since 1968, replacing the earlier models 4 and 4A. Although
it is now being replaced by more modern devices, it is a well built and generally reliable detector.

The mine detector is supplied dis-assembled in a wooden box for storage and transit.

The box contains..

Search head.
Telescopic handle.
Amplifier unit.
Battery extension cable.
Test box No1/No2.
Spare trimmer cover.
Cleaning cloth (in can).
Wooden measuring stick.
User Handbook.
Log Book.

The detector is of the induction-balance type. The search head containing two mutually-reacting inductance coils.
The coils are balanced by means of a dust core trimmer assembly with course and fine adjusters. When correctly
adjusted the mutual inductance of the two coils is in balance. When any metal object is brought within range of the
coils, the balance is distorted, resulting in an audable tone in the headphones.

The amplifier unit has two controls, OFF-NORM-PAVE and REGEN. Normal is used for most ground types,
Pave being used for soil types containing ferrite or other metallic splinters.

The operator's manual for the mine detector gives details of
setting-up calibration and use, I have included a copy in PDF
format on this web page. Over the past six years I have used
this mine detector for many hours, It is fairly heavy and a
good way of building muscle on your fore-arms.

The detector is an all-germanium-transistor design, and uses
a single 9 Volt battery. Previous versions were valve based
and required special batteries to supply the various voltages.

Although the mine detector 4C was originally designed to use a
now almost obsolete PP6 type battery, it works very well with
PP3 types. The current consumption is under 4mA and this gives
an estimated life, when used intermittantly of 300 hours with a
zinc-carbon PP6. Similar battery lives have been noted when using
high quality alkaline PP3 batteries.

The Mine Detector 4C can detect the larger metallic mines, like the British Mk7 anti-tank mine to depths of
around 20 inches, and metal bodied fragmentation grenades at over 12 inches. (see manual for more details).

(I also use a MineLab. which is more sensitive, lighter and microprocessor controlled, but eats batteries).

Download the User's Manual for MINE DETECTOR 4c here.