tr metal detector

[Esteban]

I built similar detectors. And my advise for who want... First of all you have to make good mechanical construction for coils. It must be hard. Even very good circuit won`t work without it.

Yes, this is true.

[Esteban]

YOUR OPINION ABOUT THIS CICUIT????

I respond you in other post: "Maybe somebody build it. For me, is complicated for 2 box."

[Gervm]

It`s more liked on usual VLF IB metal detector. With the same success you may use TR coil construction with any detector of this type. I prefer "hear what I`ve transmited". For it several reasons. Power of transmiter may be medium or low but gain of amplifire must be high and the higher the better. Also on low frequency I use signal compensator to reduce leftover signal from TR coil. I don`t see it here so I think - It will be very difficult for this detector to find auto car (large target) at distance 3-4m.

[Esteban]

It`s more liked on usual VLF IB metal detector. With the same success you may use TR coil construction with any detector of this type. I prefer "hear what I`ve transmited". For it several reasons. Power of transmiter may be medium or low but gain of amplifire must be high and the higher the better. Also on low frequency I use signal compensator to reduce leftover signal from TR coil. I don`t see it here so I think - It will be very difficult for this detector to find auto car (large target) at distance 3-4m.

This deppend of size of the 2 box too. I've seen a 2 box with 3 mm aluminium wire in coil, transmitter push-pull BD135-136. This detector is carry by 2 persons due the weight, but depth is more than 5 meters for big objects. Now, consumption is high and "out the regulations". Excess of sensibility in receiver can be bad, causes of inestability, you must found best point.

[Gervm]

I also saw similar detector with two operators. It was early russian bomb detector. But now it possible to build simple and cheap device with the same parameters by using opamps. I can draw circuit that designed several years ago but I need time. It was "wet" but worked enough stable.

[Esteban]

I also saw similar detector with two operators. It was early russian bomb detector. But now it possible to build simple and cheap device with the same parameters by using opamps. I can draw circuit that designed several years ago but I need time. It was "wet" but worked enough stable.

Maybe. But here sometimes a couple of many ICs can't replace few transistors. I think that 2 box must be "crude" type...