Transistor Theremin by Alexander Zeyliger

[Andreu]

I would like to build the Transistor Theremin designed by Alexander
Zeyliger but I need some help. I have some questions to be answered,
I
know they are so basic....

What kind of capacitor is needed? I mean: ceramic, electrolytic,
etc...
It will works if the power supply is a 12VDC battery charger?
It's so important to build it on a PCB? It's hard to build this
project?
I'll get any sound if I haven't got an oscilloscope to tune it?
Any suggestion for a 2N2222A equivalent?

You can find the schematics and information here:
http://www.theremin.info/info-134-Transistor_Theremin.html

Thank you in advance