AMZ Mini Booster based circuit mobile phone interference

[chobot123]

Good idea!
I still have the prototype, so I can even drill a new hole for the pot. The existing gain pot is PCB mounted.
I'm afraid that I won't have time for it until next weekend, but will try it for sure. Need to learn my lesson from this project and this brainstorming is a good part of it.
Thanks to all people on this forum. Very helpful.
Have a nice day

[bool]

One possible way for RFI injection in your mu-booster is through the upper fet's gate. As-is, this mu-follower has high-ish output impedance so some RFI can get in via the "output" or wiring (so through the lower-drain/upper-source connection and then through the cap into gate.

So try to decouple the upper gate and see if this helps a bit.

Other than that is, you can very much just drop-in change the upper fet for a bjt in this type of circuit so there's another avenue to try out and see if there's a change for the better.