How to construct the psychophone
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Constructing the Psychophone

Building this device is not as difficult as it seems. My knowledge of electronics is rather limited and still I managed. And because the diagram is very simple many of you will probably be able to build it yourselves.

I have also provided a lay-out that you can use as a transparant for etching a print.

On the picture on the right you can see what the interior of the Psychophone looks like.

Furthermore, there is a diagram in which you can see how the various components should be connected.
Click on the picture to see an enlargement.

I also included a list with al the components needed and some information about winding the spools.
Although constructing the Psychophone should not give you too much trouble, some patience an handiness might still be necessary. I wish you as much pleasure as I had building this device.

Pre-amplification of the microphone

I can be brief about that. I use a construction-kit from a company named Velleman. I guess there are more available. They are easy to finish and serve their purpose well, without producing too much noise.
See picture 4


 • Above you can see the Psychophone’s diagram with values of resistors and capacitors
• Power supply : 9 Volts DC.
• Transistors.
• npn-high frequency transistors for the 4 high-frequent stages.(v.1;v.2;v.3 and v.4).
• type bf 194 or equivalent (bf 254).
• In the low frequent stage the 5th transistor of type bc 147 or equivalent type.
• High frequency diode of type aa 166 or equivalent type.
• Resistors.
• Power consumption 0.25 watt, low-noise type.
• R1=10k ohm;R2=2.7k ohm;R3=470 ohm;R4=1k ohm;R5=15k ohm;R6=100k ohm as small fixed regulator (a so-called "preset");R7=1k ohm;R8=5k ohm,a potentiometer("blitz" regulator);R9=3k ohm;R10=820 ohm;R11=470 ohm;R12=3k ohm;R13=5k ohm;R14=100k ohm a potentiometer;R15=470 ohm;R16=470 ohm;R17=10k ohm;R18=2,7k ohm;R19=6,8 ohm;R20=350 ohm:R21=2k ohm;R22=15k ohm;R23=100k ohm;R24=10k ohm.
• Capacitors.
• 12 tot 15 Volts DC.
• C1=10 nf;C2=47 nf;C3=10 nf;C4=10 nf;C5=200 pf;C6=47 nf;C7=200 pf;C8=47 nf;C9=10 nf;C10=4,7 nf;C11=10 ΅f;C12=10 nf;C13=10 ΅f;C14=10 ΅f;C15=470 ΅f;C16=470 ΅f;C17=1 nf;C18=10 ΅f (΅f = micro farad, these are electrolytical capacitors
• While constructing bear in mind the “+” and “-“ -side !!!
• Winding information.
• For all spool the same winding direction, 0.2 mm copper-enamel-wire.
• Circuit L1 collector-circuit,30 windings.
• The beginning of the winding connected to collector, the end of winding connected to “+”.
• Circuit L2, emitter circuit, 20 windings.
• The beginning of the winding to "blitz"poteniometer of 5k ohm, end of winding to “ground”
• Circuit L3, base-circuit of the 3rd transistor, 30 windings.
• Beginning connected to 200 pf capacitor.
• End of the winding to" ground " so the neg.-side!
• One might also try more or less windings on a ferrite bar and mount in a way so that the emission isn’t muted too much by the aluminium of the case.
• So don’t mount too close to the metal!!.
• The self-induction of the spool has to be several mH.
• May be replaced by an appropriate resistor.
• V.B.:2mH/10 mf=35,5 Khz.
• 2,5mH/10 mf=32 Khz.
• ps: L4=20 windings on the ferrite bar.


   © Jean de Meulder