Minipulse plus revision D advice sought.

[Treasuremole]

Hi there fellow builders!
I'm quite new to building electronics and this is only my second kit.
I've built a surf pi and now the mpp both from silverdog and have thoroughly enjoyed both projects. While both machines worked first time and both have been out and tested on the beach (and found many items including a 2 gram emerald a gold ring with the mpp) I am still having issues with getting the right values for the coils... Have made quite a few now from 220uh to 503uh But would like to know if there is a magic number for both the machines?
Currently I'm using the same shaft for both machines. Any help gratefully received 😁

[KRinAZ]

Hi there fellow builders! I'm quite new to building electronics and this is only my second kit. I've built a surf pi and now the mpp both from silverdog and have thoroughly enjoyed both projects. While both machines worked first time and both have been out and tested on the beach (and found many items including a 2 gram emerald a gold ring with the mpp) I am still having issues with getting the right values for the coils... Have made quite a few now from 220uh to 503uh But would like to know if there is a magic number for both the machines?Currently I'm using the same shaft for both machines. Any help gratefully received 😁

Hi Treasuremole, congrats on your finds with your machines! I haven't built a Surf PI but do have a very recently finished MPP that I now use daily - I've had very good performance with both 300uH & 360uH coils. I believe Qiaozhi's spec in the project docs is 300uH for the MPP.