Need information on this metal detector....

[fwcrawford]

A co-worker brought this detector in the other day and asked me to check it out and see if it works.
He said it belonged to his grandfather and had been leaning up against a corner wall for who knows how long.
It is made by a company call "DE-TEX" out of Garland,Texas and is called the " PROFESSIONAL" model.
Being I have only been in the detecting hobby for about 5 years, this is way before my time, but I am guessing it is a BFO type detector.
It has four knobs and a switch for a backlight for the meter.
The knobs are labeled as follows:
Knob 1.. Metal/ Mineral
Knob 2...Balance
Knob 3...On/Volume
Knob 4...Off/Batter/Metal
It has an external speaker and a 1/4" jack for headphones also.
I would appreciate any information on explanation on the function of the knobs.
The connector is missing from the coil connector on the cable, and I don't have a clue where to start looking for a replacement except Mouser Electronics, so could also use some help on this too.
Thanks in advance for looking an any help,
Felix

 

[Mtnmn]

D-Tex Electronics Co. (D-Tex metal detectors) was founded in 1956 by Bill Mahan and went out of business in 1984 after which the owner's son took the remaining parts and bought out and took over the Gold Mountain Metal Detector Co. It operated until the early nineties at which time it apparently went out of business too. The missing connector cable on your friend's detector could probably be made and replaced by a electronics shop.

 

[Dave J.]

The control box looks like a pre-VLF "TR" induction balance machine. However the searchcoil looks like it's not an induction balance type, but from a BFO.

--Dave J.

 

[ron_c]

A D-Tex BFO was the first detector I had in '68. I had the "Deluxe" model or it could have been the "Professional" model, just don't remember. It came with, as I recall, a 12" coil and either a 6" or a 8" coil. The thing I do remember, it drifted so bad I was constantly adjusting the Metal/Mineral control, especially if you walked from sunlight into shade and back again. Only had it for a couple of months, traded it in for a Garrett BFO with 0 drift technology.

 

[fwcrawford]

Hey Ron,
Thanks for the response!!
It sounds like you have had some experience with this brand and type of detector.
I am not quite sure how to adjust the controls on this one or what exactly the function of them is.. much different than the detectors I have.
Could you explain what the functions of the knobs are and how to go about setting this machine up to detect?
I'll tell you what I think I understand from my research... the balance knob sets up the balance of the two coils ( one located on the search coil and one in the control box ).
It is adjusted until the meter reads " 0" which is the middle of the scale.
The mineral/ metal knob is a form of discrimination.
The off/ battery/ metal knob is used to turn the machine on and off, check the battery power, and then switch to detecting mode.
Does this sound right to you?
I did notice that the needle on the meter hangs up about 1/4 to 1/2 of the scale and I have to tap the box to get it to reset to the bottom of the scale.
This is preventing me from being able to balance out the coils, plus I assume that with a fully charged battery, when switched to " battery", the meter should go all the way over to the right side indicating a charged battery.. is this correct?
I replaced the coil cable this morning and now have some sounds coming out of the speaker when adjusting the balance knob, but do not get a signal when moving a coin past the coil.
I ohmed out the coil and it read 1.5 ohms. I don't know if this indicates a good reading or bad, but at least I know it is not an open circut.
I would appreciate any help you can give me on setting this machine up so I can inform my co-worker if it works and how to make the adjustments.
Thanks again,
Felix

 

[fwcrawford]

n/t

 

[ron_c]

The only controls I recall on the D-Tex was the metal/mineral control, on/off/battery check and perhaps volume control. The one I had didn't have the Balance control and I may have had either an earlier or a later model than the one shown and as I recall it was the "Deluxe" model. Also, the meter on my unit was used for battery check and was an intensity meter. The 0 on the meter was on the left side and went to something like 50 on a scale as I recall. The further a target was from the coil the less the meter moved to the right.

The metal/mineral switch was for searching for non ferrous targets when adjusted into the metal side until you received a putt - putt like motor boat sound. Too low a sound or too high and it was hard to hear a hit on the deeper targets. It was not silent, it was a constant sound and when hitting a target the sound would increase if a non ferrous target was detected or it would null out over iron.

Your meter may have been nothing more than a visual aid when finding targets, moving one way for non ferrous targets and going the other way for ferrous, just not sure.

As far as Balancing the coils, on the unit I had I didn't have the Balance control and I just swapped coils, readjusted the metal/mineral switch and off you went.

Also sending you a PM.

 

[fwcrawford]

Thanks for the help Ron.
I believe the meter is as you described.. needle moves one way for ferrous targets and the other for non-ferrous targets.
I'll pass this info. on to my co-worker.
Felix