Finishing two 3DSS coils

[Roo2]

Hello,
Ive returned to get on with finishing a couple of MPP RevD detectors and need some help picking up where I left off a little over three years ago.. I got distracted with other stuff..
Anyway.. Three years ago I wound two 10” mono coils. Photos attached. Ive found some notes indicating they both have 30 turns so far.
One is PTFE insulated 24AWG multistrand wire (0.511mm).
The other is Litz 175/46 23.5AWG wire (0.541mm).
I just used my low cost LCR meter to measure:
PTFE coil: 2.6ohm, 0.40mH
Litz coil: 9.7ohm, 0.48mH
I suspect the inductance measurements arent great but the resistance measurements align well with my Fluke multimeter.

Unfortunately Ive forgotten quite a lot about this project in the last three years.. My question is.. Should I add or remove windings for a Minipulse Plus D? Ie, whats a good target inductance and how do I get there from here for each coil? Ive tried to use the coil calculator in the first post but it doesnt work on any of my iOS devices...

[lamoiz]

Hello,
Ive returned to get on with finishing a couple of MPP RevD detectors and need some help picking up where I left off a little over three years ago.. I got distracted with other stuff..
Anyway.. Three years ago I wound two 10” mono coils. Photos attached. Ive found some notes indicating they both have 30 turns so far.
One is PTFE insulated 24AWG multistrand wire (0.511mm).
The other is Litz 175/46 23.5AWG wire (0.541mm).
I just used my low cost LCR meter to measure:
PTFE coil: 2.6ohm, 0.40mH
Litz coil: 9.7ohm, 0.48mH
I suspect the inductance measurements arent great but the resistance measurements align well with my Fluke multimeter.

Unfortunately Ive forgotten quite a lot about this project in the last three years.. My question is.. Should I add or remove windings for a Minipulse Plus D? Ie, whats a good target inductance and how do I get there from here for each coil? Ive tried to use the coil calculator in the first post but it doesnt work on any of my iOS devices...

the two are very good, I find all the same that the measurement of resistance of that in wire of litz is very high. Have you removed well the insulation of each strand? both will go on the mpp, but above all, the most important is to properly calibrate the damping resistance.

[Roo2]

Happy holidays all! Thanks for your reply lamoiz.

Yes, I noticed the high resistance. I think that may be because instead of cutting the wire and stripping it to measure I drove a pin through the insulation. I suspect it was only contacting a few of the copper conductors, not all.

I’ve found a coil calculator that appears to calculate similar inductance for the 30 turns. I think I read somewhere that around 300mH might be a good inductance for the MPP. Does that sound right? If so, I need to reduce them to about 25 turns to achieve that.

[lamoiz]

Happy holidays all! Thanks for your reply lamoiz.

Yes, I noticed the high resistance. I think that may be because instead of cutting the wire and stripping it to measure I drove a pin through the insulation. I suspect it was only contacting a few of the copper conductors, not all.

I’ve found a coil calculator that appears to calculate similar inductance for the 30 turns. I think I read somewhere that around 300mH might be a good inductance for the MPP. Does that sound right? If so, I need to reduce them to about 25 turns to achieve that.

good evening, it is really necessary to strip all the wires, it is very important.
i think your coil value with 30 turns is ok. 480 is ok. I repeat again, it is the resistance of damping, which is really extremely important to have a delay response as fast as possible.

[Roo2]

Thanks lamoiz. I just have the listed 470R R1 fitted. I see the comment in the instructions that it may need to be adjusted but it doesn’t appear to describe how. Can you point me to that? I’ve lost access to a CRO so it may be academic unfortunately..

[lamoiz]

Hi,
indeed the right value must be found, 470r is a theoretical value. for this I use a potentiometer and resistors to visualize the damping curve on an oscilloscope. Do you have an oscilo? last week, our friend Surfdetector made a good video of it on youtube, just to help beginners!

[Roo2]

Thanks lamoiz. No access to an oscilloscope at the moment but please post the link to the video.

[lamoiz]

Thanks lamoiz. No access to an oscilloscope at the moment but please post the link to the video.

https://www.youtube.com/watch?v=CrJ5tFFmWyo
https://www.youtube.com/watch?v=Gr__N4_k2Mc
voila !

[Roo2]

Merci lamoiz and Surfdetector. I probably should get an oscilloscope..

[lamoiz]

Merci lamoiz and Surfdetector. I probably should get an oscilloscope..

yes, it is often essential for the realization of electronic circuit. there are mini osciloscopes on the net, mini DSOs which provide a lot of services, at a lower cost!
par exemple: https://www.ebay.fr/itm/DSO188-Porta...wAAOSwEOhfpOwx

[Roo2]

Thanks. I’ve wondered about those. Do they have a useful sampling rate and bandwidth for PI detectors?

[lamoiz]

Thanks. I’ve wondered about those. Do they have a useful sampling rate and bandwidth for PI detectors?

the one I have in the link was taken at random as an example. there are indeed several different qualities on this kind of oscilloscope. there are some which have 2 channels, which is already a good point. I think that for most PI machines, it will do the job, probably less precise than a 2ghz lecroy, either, but it will allow you to see the essential all the same.

[Roo2]

I've found a friend that has an oscilloscope so I'll put together the variable resistor rig and go and visit him in a week or two. Thanks for the advice.

[6666]

Happy holidays all! Thanks for your reply lamoiz.

Yes, I noticed the high resistance. I think that may be because instead of cutting the wire and stripping it to measure I drove a pin through the insulation. I suspect it was only contacting a few of the copper conductors, not all.

I’ve found a coil calculator that appears to calculate similar inductance for the 30 turns. I think I read somewhere that around 300mH might be a good inductance for the MPP. Does that sound right? If so, I need to reduce them to about 25 turns to achieve that.

Hello Roo2 would you mind posting a link to that coil calculator thanks

[Roo2]

Hello Roo2 would you mind posting a link to that coil calculator thanks

Here you go:
https://www.diyaudioandvideo.com/Cal...uctorDesigner/

I made the coil length very short. Say about 0.25? or something