Here I present a version which is a perfect combination of the 2 circuits above.
I use the modern NTC module together with the PNP Ge transistors. Of course, you can use some legacy Lectron blocks as well, the NTC however is the new modern version of 6.8k
For this, some changes of the circuit components were necessary.
And it performs amazing ! Such a good sensitivity !
When you form your hand around the NTC, the meter starts to deflect.
When removing your hand and cooling down the NTC, it takes some time to recover to the original position.
Try it out for yourself and be surprised !
Here’s the diagram :