Threshold Pot doesn't work

[Carl-NC]

16Hz I think.

[h9361]

16Hz I think.

Hello
Dear Carl
The www.longrangelocators.com can not load, i think it has error.
Is it possible to check it?
Thanks.

[Carl-NC]

I'm aware of the problem.

[h9361]

I'm aware of the problem.

Hello
Dear Carl
Please forgive me for my question.
Please consider Inside of metal detector ( second edition), p. 37, Off-resonance.
I want to change its oscillator with oscillator of raptor ( attached).


Do you think the schematic of your off-resonance need to be changed if i connect output of raptor-oscillator to 1n914 in your off-resonance schematic?

[Carl-NC]

This won't work. The raptor oscillator is "on-resonance" and can't be forced off-resonance.

[h9361]

This won't work. The raptor oscillator is "on-resonance" and can't be forced off-resonance.

Dear Carl
I have a question about Commercial pinpointer metal detector.
Do you think its method is Off-resonance like in your book?
Thanks

[Carl-NC]

The only pinpointer I know of that uses off-resonance is the Cache Pro by Intex Systems.

[h9361]

The only pinpointer I know of that uses off-resonance is the Cache Pro by Intex Systems.

Thank you.
Dear Carl
Have you ever tested search part from www.longrangelocators.com?
I think the part is not working because it shows nothing for every keywords.

[Carl-NC]

I'll look into it later.

[h9361]

I'll look into it later.

Hello Dear Carl
I hope you are passing good days.
Please see the schematic, it belongs to Mr. Donald. He told me that its response frequency is 7Hz.
I want to adjust it for using my HHD. As you told me, HHD response frequency is 16Hz.
Is it possible to tell me which parts is better to be changed ( its values) for reaching the 16Hz?!
Thank you.

[Carl-NC]

The bandwidth is set by R20 and C15:

BW = 1/(2 * π * R20 * C15) = 1/(2 * π * 2.2M * 10nF) = 1/0.138 = 7.23Hz.

So if you change R20 to 1M the BW will be 15.9Hz. You will also need to change R25.

It is not absolutely necessary to have 16Hz, you can change it to a lower or higher BW and see how that affects the target response.

[h9361]

The bandwidth is set by R20 and C15:

BW = 1/(2 * π * R20 * C15) = 1/(2 * π * 2.2M * 10nF) = 1/0.138 = 7.23Hz.

So if you change R20 to 1M the BW will be 15.9Hz. You will also need to change R25.

It is not absolutely necessary to have 16Hz, you can change it to a lower or higher BW and see how that affects the target response.

Thank you for your valuable information.

[h9361]

The bandwidth is set by R20 and C15:

BW = 1/(2 * π * R20 * C15) = 1/(2 * π * 2.2M * 10nF) = 1/0.138 = 7.23Hz.

So if you change R20 to 1M the BW will be 15.9Hz. You will also need to change R25.

It is not absolutely necessary to have 16Hz, you can change it to a lower or higher BW and see how that affects the target response.

Hello Dear Carl
I have a question about IMD2, chapter 8, Transmit-receiver Detector. Do you think the simple schematic can detect microvolt variation (high sensitivity) on amplitude of Signal?
Thank you

[h9361]

The bandwidth is set by R20 and C15:

BW = 1/(2 * π * R20 * C15) = 1/(2 * π * 2.2M * 10nF) = 1/0.138 = 7.23Hz.

So if you change R20 to 1M the BW will be 15.9Hz. You will also need to change R25.

It is not absolutely necessary to have 16Hz, you can change it to a lower or higher BW and see how that affects the target response.

Dear Carl,
I already added a GB to my HHD. Now, i am going to test your Bipolar GB method to my HHD.
Is it possible to see the schematic and see that whether it has any error or not (specially 5532 part, negative/positive voltage output)?!
The voltage level of my four sampling pulses is +5V.
Thank you.

[Carl-NC]

That looks OK to me.