Metal Detector Coil booster

[Qiaozhi]

Yes I would guess that were one to add components into a balanced circuit there would be circuit operational changes. BUT the task here is to recognise that some very major manufactures - Minelab, Tektronics, and I believe Garrett- all had just such an optional external power amp available for those old workhorses. We all know they were smart people Plus owners/operators have reported that they did work. So the question becomes why and HOW did they design the "add-on" circuit to overcome the negitive effects and rebalance the circuit when the circuit was added on. ??? This is not intended as a technical design forum/debate. We are simply asking if there is a few schematics out there that folks can share with us; even internal photos would help the thread. Also helpful and interesting would be first hand experience stated in a down to earth manor with no techno jargon. Anyone??

I vaguely remember someone saying that the audio output was routed to the coil connector on some machines. Therefore, what might appear as a TX booster could actually still be an audio compressor. Alternatively it's possible that the add-on device is be an RX amplifier. It will be interesting to see if anyone has any information.

[turtlebowl]

Audio Amp with signal limiter drawing

I found the drawings and will attempt to upload them now. Besides the standard circuit shown here we also producted one with 3 different levels of amplification, as well as one with a 10 segment LED bar graph which measured intensity of the original signal (helpful for night hunting and depth reading). I can't find the triple boost drawing. But have the LED version , I'll need to clean up the drawing alittle before scanning it. Maybe next week?? I've never tryed the pix upload here yet so my fingers are crossed......which makes it all the harder to do it! hehehehahaha........here goes with the version one upload.

[Obn]

Doc's audio amp

http://www.youtube.com/watch?v=Y8v0lBff1lU

PP/AM mode on excalibur only, What you are doing is separating target from threshold. When you turn down the threshold on the excalibur, at the point of just audible, the threshold is still covering up targets...once you lower the threshold to it's lowest point, these targets are uncovered and the amp allows them to be heard. The threshold of the excalibur does not stop, like falling off a table..it's a gradual slope. The Amp allows you to hear the full extent of the threshold, along with the targets it has covered. And to all fairness to the Df, only my second time out with it, but have done several run in compares with different hunters over the past couple years at several different beachs in the US and only detector that can match the Amped excalibur on small deep targets is the infinium....Shaun's Amp for sovereign, no scmat for it and cannot be copied...

http://forum.treasurenet.com/index.p...,375221.0.html

[Obn]

Shaun's Amp

Goes between the coil and the control box of the Sovereign, no scmat on this plus some of the chips have been cleaned so it can't be copied.
http://www.findmall.com/read.php?21,1365516