Here’s another simple schematic, based on my Super Simple Three Dial, and using the amplifier from the Wishing Machine posted yesterday. The Aerial is an optional extra, and is in no way necessary. You could experiment to see if it increases your output. As before most of this can be done with crocodile clips if you aren’t used to solder and soldering irons. I would add that it would be a good idea to secure and insulate the crocodile clips on the pins of the potentiometer, so that they are secure from pulling lose, and that the tips of the other leads don’t touch creating a short circuit.
I’d recommend either using 10K, or 100k ohm potentiometers with this radionics machine. Maplin, and RadioShack sell these, but for some reason they have increased in price over the past few years. The ones pictured are 10K linear carbon track pots, but I’ve now taken to bulk ordering wirewound potentiometers for all of my projects as I like the feel, responsiveness and construction of them.
The plates can be copper, brass or stainless steel. Any metal will work, but those are the ones I’d recommend. You could replace them for wells if you wish, large copper end caps work nicely for this purpose, or things like metal beakers.
Use a snap on connector with your 9v battery, you can get these at any online or local electronic store, I just source mine on Ebay. Since this circuit lacks a switch, all you have to do is unclip the battery to switch it off. If you want to install it in a case, then use a simple SPST (Single Pole Single Throw) switch inline with the Red wire from the battery.
If you want to go all out and build it in a case, then you’ll need some dials, and a scale. I recommend base 10 scale, but you could easily invent your own and experiment with it. Joseph Max of Aetheric Arts has a nice base 100 graphic which you can print out from the image here. You need a potentiometer dial. There are many to chose from, but look for one that can take a 6mm shaft, or equivalent to the potentiometers you are using.
The amp can be found at this link among many others. It’s low powered, but gives moderate results. I’ll aim to do a more advanced drawing soon with two power amp stages, and wire wrapped crystals. I’ll do something similar with the wishing machine as well.