Sniffer XR-71 help

[Jafar]

text

"Should I connect the oscilloscope ground probe to pin 1 of D6 in order to measure the output of the LF357 preamplifier?"

[Jafar]

text

[kt315]

"Should I connect the oscilloscope ground probe to pin 1 of D6 in order to measure the output of the LF357 preamplifier?"

yes

[aft_72005]

Hi Jafar.
I built the Delta Pulse years ago... it worked well.
If I can find the circuit, which is in the storage room at home, I will turn it on and upload pictures of the waveforms of its various points here.

A photo of old Delta Pulses that I found on an external hard drive.

from year 2009

[aft_72005]

search coil

[aft_72005]

input preamp pin2 opamp

[aft_72005]

preamp pin 6 opamp

[Jafar]

preamp pin 6 opamp

Where did you connect the oscilloscope probe’s GND in this measurement? When I connect the GND clip to the circuit’s virtual ground, nothing appears on the screen — but when I don’t connect the oscilloscope’s ground probe, a waveform is visible.

[Jafar]

Hi Jafar.
I built the Delta Pulse years ago... it worked well.
If I can find the circuit, which is in the storage room at home, I will turn it on and upload pictures of the waveforms of its various points here.

Hello my friend, thank you for taking the time to send it. If it’s not a bother, I’d like to stay in touch with you more. If you have any way of contact available — such as email or Telegram — I’d appreciate it.

[aft_72005]

Where did you connect the oscilloscope probe’s GND in this measurement? When I connect the GND clip to the circuit’s virtual ground, nothing appears on the screen — but when I don’t connect the oscilloscope’s ground probe, a waveform is visible.

Connect the oscilloscope ground to the virtual ground. I did the same thing.
pin1 TL062

[aft_72005]

Where did you connect the oscilloscope probe’s GND in this measurement? When I connect the GND clip to the circuit’s virtual ground, nothing appears on the screen — but when I don’t connect the oscilloscope’s ground probe, a waveform is visible.

Connect the oscilloscope ground to the virtual ground. I did the same thing.
pin1 TL062

[aft_72005]

Hello my friend, thank you for taking the time to send it. If it’s not a bother, I’d like to stay in touch with you more. If you have any way of contact available — such as email or Telegram — I’d appreciate it.

Yes, via the Telegram app.
I am also happy to answer any questions you might have here, to the best of my knowledge.

[Jafar]

Yes, via the Telegram app.
I am also happy to answer any questions you might have here, to the best of my knowledge.

Thank you for your kindness. I truly appreciate your help. @amirali_sa_13 — this is my Telegram ID. I’d be happy if you send a message; I’ll be waiting for you.