Contents of the box
Detector head assembly, Electronic unit, Headphones, Headphone extension lead, Battery extension lead
Two test targets, Log book, Telescopic handle, Measuring stick
The log book shows it was regularly tested from 1989 to its last operational date of 1996 by 28th Engineering Regiment, BFPO31, wherever that is *, and a label on the box declares it was finally sold in January 1998.
The detector takes a 9 volt battery with a clip the same as a PP3, one of which is included, and the box is very substantial and waterproof when closed with its 6 clips. The seller wouldn't budge from his asking price of £10.
Sometime I'll unpack it all and see if it works.
I was browsing round an antique shop the other day and noticed a large wooden box with military markings, that looked strangely familiar.
I opened the lid and inside was a P6 mine detector (see below). Shock... I used to manage the Department that designed these things! Seeing it being sold as an antique wasn't too pleasing. I asked the proprietor about it. It's got batteries fitted and we tried it out. It works OK he said and it'll cost you £90. I said we used to charge MoD nearer £1200 and declined his offer. Somewhere I've got one. I'll dig it out and add a picture. It's the same type I demonstrated to the Swedish Army (click to see). I also saw a P7 advertised on Ebay (see below), but again a bit expensive for an impulse buy. The P7 was developed by my Department at Plessey in the Thatcher days when terrorist activity in Northern Ireland was at its peak. It was designed for detecting the command wires to explosive devices hidden along roads. These wires were difficult to detect as they were often extremely thin to avoid detection, but the P7 used a section of the command wire to link a transmitter and receiver in the detector head. Plessey made around 120 or so (at least) and made loads of money from the PDS contract. The reason being that the P7 was used as a height detector by soldiers. A "height detector" you might ask...
Well, have you noticed how heavy anything military is? A clue to this is the P7 height detector.
When a search for command wires was about to take place a platoon was sent by helicopter to inspect suspect fields. Once ready to disembark a soldier would chuck out his P7. Usually it broke. If it did he'd wait a little longer before jumping out. Over the years we progressively strengthened the P7 by using stronger and stronger (and of course heavier) materials until I guess the P7 survived the drop but the odd soldier presumably broke his leg ? I wonder if anyone reading this knows anything about the P7 and just how successful, or otherwise was it? It can't have been too bad because one day an Irish policeman rang me wanting to buy a few.
One day someone had the bright idea to make a commercial version of P7 and flog it to the local water company to find buried pipes. An engineer turned up at the local water board offices and went out with our new P7 to demonstrate it. Much to his surprise the water board chap fished out of his car a divining rod. At the end of the day we'd proved P7 worked well, but no better than the divining rod so we abandoned the idea....
Click to see the first military metal detector described in March 1916
Reading the accompanying text, the detector has two 70cm coils suspended from a bamboo pole. A remote box, carried by a chap wearing headphones, contains a battery, a condenser, a buzzer and a balancing circuit. In operation, the two coils are coupled by a metal object (in this case a large unexploded shell) inducing noise from the buzzer radiated by one coil, into the second, where it is heard in the headphones. The circuit is described as induction balance which is the same method used by the Plessey P7 used for command wire detection.
Pictures of the Plessey P7 designed for use in Northern Ireland
And here's a Plessey P6 (L4A1)
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