MPP beach rev-e problem

[convola]

tp9 min and max position like this. reject pot min and max position.

[Qiaozhi]

tp9 min and max position like this. reject pot min and max position.

Your receive signal is taking about 100us before it gets above zero, so the problem is nothing to do with the sampling.
Is your coil severely overdamped?

[convola]

Your receive signal is taking about 100us before it gets above zero, so the problem is nothing to do with the sampling.
Is your coil severely overdamped?

you are right. it is aproximately 90us. How many microseconds does it need to be?

[convola]

Your receive signal is taking about 100us before it gets above zero, so the problem is nothing to do with the sampling.
Is your coil severely overdamped?

thank you. I used this cable to connect the coil to the circuit. When I removed this cable it became approximately 14us.

[convola]

thank you. I used this cable to connect the coil to the circuit. When I removed this cable it became approximately 14us.

[convola]

The problem was solved and it works very well now. Also I used 4066 instead of j113. thank you very much

[Qiaozhi]

The problem was solved and it works very well now. Also I used 4066 instead of j113. thank you very much

That's good.

[cristiano.sar]

I just finished Minipulse but I have not followed the step by step during the assembly. It works, but I'm lacking some distance/depth. Can I follow the testing/tunning steps even after all the components in place? Thanks.

[Qiaozhi]

I just finished Minipulse but I have not followed the step by step during the assembly. It works, but I'm lacking some distance/depth. Can I follow the testing/tunning steps even after all the components in place? Thanks.

Yes.

[cristiano.sar]

Here is a small video testing my Minipulse: https://www.youtube.com/shorts/eY49lD1dBcw
I think I still need some adjustments but for me the performance is good with a 20cm coil I also use in the Felezjoo.
Do this kind of spider coils need shielding? Thanks!

[cristiano.sar]

I think you may be confused about the sample timing.
TP6 is the sample delay, and TP9 is the main sample.

It seems my TP6 is wrong as apparently there is no delay (the sample pulse is starting immediately after the TX pulse collapses without delay):
Scope settings are:
Time/Div: 50uS
V/Div: 5V
Trigger: Channel 1

What could be wrong? Thanks

[Qiaozhi]

Check the value of C13. It should be 220pF.
Also, check whether adjusting R37 has any effect on the delay pulse at TP6.

[cristiano.sar]

Check the value of C13. It should be 220pF.
Also, check whether adjusting R37 has any effect on the delay pulse at TP6.

thanks, I changed the capacitor, for another with a little more precision but the result is the same. Adjusting R37 works (affects the delay pulse.)

[Qiaozhi]

thanks, I changed the capacitor, for another with a little more precision but the result is the same. Adjusting R37 works (affects the delay pulse.)

With C13 as 220pF and R37 (100k) set to maximum resistance, the delay should be 220E-12 * 100E3 = 22us.
Perhaps U7 is faulty.

[cristiano.sar]

I think it's all correct. Anyway I replaced U7 (the pulse has a better appearance now). But in previous question I made a confusion about the delay (I thought this was the space between TP2 and TP6, but it really is a pulse)
Here are the pictures of TP6, TP8 and TP9:



Thanks.