Question about the Kustom Theremin Schematic

Hello fellow theramin enthusiasts,

Having experienced the beauty, first hand of what it's like to watch someone play a theramin, I decided to take it upon myself and 4 other students to construct a theramin for a group project. 

We are using this schematic:

http://www.thereminworld.com/files/Pages/28/files/Kustom.pdf

I just had a quick question. The variable inductors, variable transformers are not labeled on the diagram. Is this an indicator that we use our own values depending on how we want the theramin to sound? I'm in charge of schematic design and sourcing parts and so I'm a bit confused as to what the missing part schematics mean. 

Thank you

Since the Kustom Theremin is based on the Moog Melodia Theremin, you will find the inductor specifications googling for Bob Moogs article about the latter. ;-) 

Hello Saling,

Here is a parts list that is very close to the kustom design.

When this theremin was designed we were still using slide-rules and 10% accuracy was ideal. There is nothing erotic about the theremin, I mean exotic so use today's modern parts. 

The pitch frequency in my schematic above operates around 150 khz so keep that in mind when selecting coil or transformer values for the kustom.

Also interesting in my schematic the pitch oscillators are drawn like PNP yet it is wire as NPN which I think is correct. I am not drinking yet so clarification from other master designers is appreciated.

Saling are you in the states? Does the group have reasonable electronic, soldering and design skills?

Christopher

Since the Kustom Theremin is based on the Moog Melodia Theremin, you will find the inductor specifications googling for Bob Moogs article about the latter. ;-)

Thank you thierry a quick google search and I came across the Moog Melodia Theremin article. It is super descriptive and explains a lot more with what is going on in the circuit.

Hello Saling,Here is a parts list that is very close to the kustom design.When this theremin was designed we were still using slide-rules and 10% accuracy was ideal. There is nothing erotic about the theremin, I mean exotic so use today's modern parts. The pitch frequency in my schematic above operates around 150 khz so keep that in mind when selecting coil or transformer values for the kustom.Also interesting in my schematic the pitch oscillators are drawn like PNP yet it is wire as NPN which I think is correct. I am not drinking yet so clarification from other master designers is appreciated.Saling are you in the states? Does the group have reasonable electronic, soldering and design skills?Christopher

Hello oldtemecula,
I am in the United States, and the group has one good circuit designer, one person who's good with antennas/ soldering, and me and another member who are also decent when it comes to figuring out the schematics and prototyping. I really enjoyed the schematic because it put things more into perspective as to what exactly the oscillators are doing and how the pitch and volume is controlled.

One thing I noticed is that the schematic requires manual coils winding for the variable inductors and transformers. You would recommend that we just use modern coils/ transformers instead of doing it by hand? Would these coils required to be variable or can we fix them at some value?