This is a simple electroscope that takes little skill to build all it takes is an analog dial, an on-off potentiometer, two or more 2N2222A transistors, and a nine-volt connector.
Here's a simple circuit diagram, the inductor symbol is a stand-in for the antenna. https://www.tinkercad.com/things/g1spRuQbVKd-exquisite-migelo/editel?tenant=circuits
Since the meter dial is hard to find I will list links to it and other components.
Meter dial https://www.walmart.com/ip/Analog-Current-Panel-Meter-DC-0-20A-Ammeter-Square-Shape-Current-Test-Mechanical-Pointer-Type-DC-Panel-Meter-Amp-Meter/1478603223?athcpid=1478603223&athpgid=AthenaItempage&athcgid=null&athznid=utic&athieid=v0&athstid=CS020&athguid=HeAp8SUygbfJGnaJ5Z2P5MxIGCBjoza8W2Ay&athancid=null&athena=true
Potentiometer-switch https://www.walmart.com/ip/4Pcs-500K-Ohm-Single-Linear-Taper-Potentiometers-with-On-Off-Switch/2502089325?wmlspartner=wlpa&selectedSellerId=101276123
Wides and screws are up to you I just had some sitting on my workbench and used them.
I have not verified these components since mine came from broken radios. If you find a problem let me know.
The author marked this model as their own original creation.