The Spring Antenna and "Perfect Linearity"

dewster good morning

I have mentioned many times I do not have a theremin anymore. I give them all away and if you look at my profile I pay people to take them and learn from them. The number is in the hundreds. How many people did you help with all your ranting fulfil their theremin dream?

Will I build another one? I am working on my final PCB given away at no cost.

With the teacher in Germany I hope to supply every student with the materials needed and a few springs. 

That would be your best bet, wait for them, creative thinkers, we are German!

“Ich bin fix und fertig!”

Christopher
www.Hwy79.com

"I have mentioned many times I do not have a theremin anymore."  - oldtemecula

I can't tell, is that a yes or a no?  Do you intend to do a video test of linearity or not?

If you won't do it, perhaps Valery can be persuaded to do so as he has a Phoenix.

Valery is a brilliant busy man and yes he sent me something and is working on something.

Is it Perfect........... NO - only our Maker is, as not a bird falls from the sky without his knowing.

A few years ago that from my minimal knowledge of DSP said you will hit a wall. Hello

Thereminist are very adaptable, that is what makes them special. If you had it your way they would all be playing keyboards.

Christopher

I owe Valery a big thanks and an apology. I complained the fisheye camera angle was not working in my favor. Like dewster thinking, dew is rubbing off.

Not Perfect but ideal for any Thereminist.

I do not think it is the spring but more to do with 10pf surface area to the environment. The proper dimensions of a telescoping antenna might be a good experiment. The 10pf and the 3300 uh choke LC I use to ground is exactly 900 khz. This also prevents static discharge issues.

Did I invent this, no I was guided to it. From the beginning I had Clara's Voice and Linearity. My job was to figure out the vehicle to embrace them.

I can only claim five octaves, above 2k is not my friend. Midi Octave 6 and lower.

Now tell Valery and me, in a positive light, why this is important today? My guess theremin interest these days is less than 1/10 it was ten years ago as that one theremin model continues to trash the dream of most people. The theremin should be simple and sound beautiful.

Christopher
www.Hwy79.com

Several people went out of their way to give something to dewsters thread and down below he throws a thankless pebble in our shoes. 

You know, if ThereminWorld were a rom-com you two would end up together 

"Is it Perfect........... NO"  - oldtemcula

I agree!

The technique in the movie is flawed though:

- Valery's body is moving around a lot, so the mid to far field can't be trusted.
- Valery's body is offset to the hand / antenna axis.
- Pitch hand position lacks sufficient consistency over the full range.
- Near field testing is fairly consistent, and near field is less influenced by the body.

Be that as it may, here I am yet again doing the work that Christopher should have, graphing the data from the video:

Near field shows characteristic cramping of a simple analog Theremin.  I knew this thread would be a monumental waste of time.

While I'm here:

"The 10pf and the 3300 uh choke LC I use to ground is exactly 900 khz. This also prevents static discharge issues."

No, you cannot rely on resonant arrangements to protect against ESD.  In many cases they exacerbate the situation tremendously.

"Now tell Valery and me, in a positive light, why this is important today?"

Because you make sweeping, absolutist statements about things you don't really test.  And you get other people to believe them.

In the picture the V is pointing at G6 and the next mark to the left is G7 double the frequency. Those of you with theremins is this distance more playable to fingering than what you get on your theremin design or the same. Many models start cramping at G5 which is normal.  Cramping is where the frequency sweeps upward in the above illustration.

Christopher
www.Hwy79.com

"Many models start cramping at G5 which is normal."  - oldtemecula

It's not heterodyned frequency which marks where cramping normally starts, but absolute distance from the antenna.

"Cramping is where the frequency sweeps upward in the above illustration."

Correct.  In the Phoenix Linearity graph, you can see the sensitivity around 100mm is roughly double that of the mid-field farther out.

I think this could be turned into a sit-com for broadcast tv - after all, The Big Bang Theory is over.

dewster you do not see the forest because it hides behind trees.

The linearity is ideal and the sound is wonderful, if only he had broken out and played a tune with that harmonically rich sound.

I myself don't like the basic theremin whistle or the kid singing with his head in a five gallon bucket.

All these technicalities makes me think you are trying to avoid the inevitable truth.

Christopher