Full m/lab SD2000 schematics

[hykj0971]

Hello zed engineer, thank you very much! I'll try to build the circuit and try the effect!

[ZED]

Heres a schematic of a pre amp with receive fets on the input,its in the ball park of what i would use,although i would use different values and components,you will need to download the zip file and unzip it,the file will need to be used in LTspice in order to see the schematic,you can play with it and see how it works.....enjoy !

[hykj0971]

Hello, engineer zed! Thank you for your advice. I bought many MOS transistors vn2410l and zvp4105a, but the parasitic capacitance is still too large and the output is abnormal. Zed engineer can give me a modified drawing, and I need to replace the two MOS, ask for the parameters to replace, thank you very much!

[ZED]

Hello hykj0971 .........I sent you a message.

[Op04]

[QUOTE = Op04; 288059]我正在关注此线程，但我仍未决定构建它。有很多我无法提供的组件。索尔特帮不了你[/ QUOTE]

Hi! You lack those electronic components, you write them out, maybe you can replace them。

Not at this moment, this project need advance attention for my own build, I cannot spent my time at this moment. Good luck with your project! Hope other's will help you

[hykj0971]

[QUOTE = Op04; 288059]我正在关注此线程，但我仍未决定构建它。有很多我无法提供的组件。索尔特帮不了你[/ QUOTE]

Hi! You lack those electronic components, you write them out, maybe you can replace them。

[hykj0971]

[QUOTE = Op04; 288059]我正在关注此线程，但我仍未决定构建它。有很多我无法提供的组件。索尔特帮不了你[/ QUOTE]

I have finished the whole circuit board, but there are still many problems, although it can start detection：哭：

[Op04]

Hi, op04! How about sensitivity and depth? Please provide the revised overall circuit diagram, thank you

I'm following this thread but I still not decide to build it. There are stil lots components I can't have. Sorrt can't help you

[hykj0971]

Hi, op04! How about sensitivity and depth? Please provide the revised overall circuit diagram, thank you

[Op04]

In audio project, I replace LM394 with 2SC1583 (with hfe 250-800) only if both emiter connected, there are 2 unused pin on LM394

[hykj0971]

[QUOTE = liekwang; 284056]先生，谁都知道可以替代LM394 [/ QUOTE]

AD797

[hykj0971]

Hello, Mr. zed! I made the SD circuit board can work, but the detection distance is too close and the sensitivity is very poor, please Mr. zed for advice, thank you!

[Orbit]

Ok Orbit i see what your saying now,i think its easier listing to the audio,you only need two hands as opposed to three hands with a scope,as for the GB pots i have owned a 2000 and a 2100 and personally i think the 10 turn pots lend themselves to some very fine GB adjustments,but still no harm in experimenting with some ideas and seeing what results you get.

Hi Zed I'd say you're right 4 potentiometers is too much ..

[ZED]

Ok Orbit i see what your saying now,i think its easier listing to the audio,you only need two hands as opposed to three hands with a scope,as for the GB pots i have owned a 2000 and a 2100 and personally i think the 10 turn pots lend themselves to some very fine GB adjustments,but still no harm in experimenting with some ideas and seeing what results you get.

[Orbit]

Orbit the 100k 10 turn GB pots can wined up in any position,it all depends on the ground.

Ok Zed I understand , I asked the question a little confusingly only when I saw it was late however I wanted to because of others to emphasize that measurements are made at the output of the oscilloscope from LT ,because somewhere it says to wave a magnet, etc. but nowhere does it say that no attention is paid to sound but measurements are taken out of lt until a response is obtained to the magnet or the response is minimal on outputs . By the way, I think that the potentiometer can be used as in the attached picture for coarse and fine adjustment .Of course the position depends on the soil ..