Question for the oldtimers

[robert roy]

Many of you have probably been MDing for years. I notice some of the metal detectors out there have no pinpoint mechanism; one has to X the target.
Were all the older detectors like this? When did they start adding a pinpoint button? Does it really add that much more to the cost of a machine to do so?
RR

 

[Xeno]

Robert,

Pinpointing mode is a non-motion operating mode. When you stop swinging your coil over a target, a motion machine tends to regard it as ground mineralization, thus tuning it out. In earlier years (i.e. the 70s and early 80s) most detectors - at least on the European market - were non-motion machines without PP buttons. When the first motion machines appeared in the 80s (e.g. the Fisher 12XX range and Tesoros), they were a great improvement over highly mineralized ground, but pinpointing needed a little practice. To make things easier, most manufacturers added a non-motion pinpoint mode on their higher-priced machines. The cost arise not from the button, but from the added circuitry.

With a little practice, you can pinpoint more or less easily in motion mode, depending on the size and shape of your coil. I owned a C-Scope TR330 and an Arado 130 years ago - pinpointing was like shooting fish in a barrel. With the 10.5'' Explorer coil it is challenging to say the least.

HH

 

[UK Brian]

Xeno hasn't quite hit the spot on this one. In the 70's and early 80's (pre the advent of motion machines) the main machines sold for detecting on land or dry sand were either I.B. (induction balance) or T.R. (transmit receive/total response).

Most I.B. machines had a narrow scan coil where only a small circular patch was very sensitive. Thus no need for any assistance with pinpointing.
Most TR's were fitted with wide scan coils where the whole head was live. This did mean pinpointing was a little harder so with the more expensive models that had two search modes...a primary deep seeking all metal one and a less deep but discriminating one. Mode change was by pressing a switch on the handgrip left or right or by pressing a button. The mode would be changed and the machine retuned at the same time. One mode or other according to the design used would scan narrower to assist with pinpointing.