Key Point: It is the length of the wire (20" is idea) that compresses the outer intervals of the low end of the pitch field and it is minimal capacitive area or small diameter of the center electrode wire that prevents compression of the note intervals next to the antenna.

There are "No" non-linear octaves in a Lev Antenna pitch field, just more or less total octaves.

I have never accepted the mechanism for pitch response as only a hand capacitive loop, like many promote, rather the mechanism is also the transfer and absorption of energy by the Thereminist body mass through the hand and fingers. There is a capacitive loop between a earth grounded theremin and its electrode/antenna with the surrounding environment, but this is unwanted and will add to environmental behavior issues, one is theremin pitch drift. Changing anything about the antenna changes this loading effect and that is why the RF Oscillators must be retuned.

From my original theremin Vision of November 2003 I used the term “Radiation Resistance” which I still consider valid. The statement also said the true heterodyne theremin of the future would "not" have antennas which always baffled me as what that meant. (electrodes?)

Radiation Resistance for me is the instantaneous total energy, of a given moment, leaving the pitch antenna divided by the square of the net current flow into the pitch antenna that generates this RF event. Energy transfer is tiny but the theremin pitch oscillator is balanced and exceptionally sensitive to any inductive, capacitance or resistive changes. Hand proximity near the pitch electrode stimulates this with minute control in shifting the loading on the pitch oscillator which shifts the capacitive reactance Xc up or down ever so slightly.

Key Point: The thin wire alone responds very poorly if not completely unusable, with only two linear octaves.  Adding a special water mix enhances the electrode/antenna's ability to transfer energy creating five to seven linear octaves. The polymer beads contribute toward environmental stability.

Key Point: If your theremin was in the AM Radio band and you compared your original 18" fat antenna to the Agua Bella 18" thin wire electrode, the RF field distance detected by the radio would have more than doubled!

The Orbeez beads can be seen below in the Agua Bella Lev Antenna on the right, the clear plastic tube above on the gray tripod. I still need to cut the vertical height down to the proper size. I used all the packets in the small box of Orbeez and they swelled over a foot taller than needed. Then I cork the top as adding water in the future will rarely be needed, the upper 1" is used without beads as a water level indicator.

If you look closely at the two Lev Antenna's, gold or speckle blue, aren't they beautiful? (bella)

The wonderful portrait in the background of Clara Rockmore was painted by Artist Corey Abbott. This was presented to me for my unrelenting research; which has always been shared freely. The portrait was a gift from master theremin builder Dana (SewerPipe)

Most of you know a plastic bottle of water near the theremin antenna will shift the pitch oscillator frequency

Key Point: The use of an non-toxic electrolytic allows for using a thinner wire diameter which reduces to a minimum the capacitive width of the electrode. This ends up better than a standard pitch antenna of the same length because this has a linear response. When this method is used for Volume Control you get more gradual shading closer to the loop. This method also eliminates the issue of touching the loop as there is no direct metal contact.

Linearity for a small person vs. someone really big is still linear, they just slightly shift the position of the Null point. There is nothing critical about the Agua Bella approach, one size should fit all.

Transistors are the main variable that encourage poorly controlled thermal drift. A theremin designer should match up similar characteristics ahead of final mounting by using a setup with special dual oscillators with transistor sockets. Then test transistors for character variances. Always use the same transistor on one oscillator side as the reference.

Some of my unbalanced theremin designs drifted one note per degree F  (that's like 1") and others were very steady over 10 degrees F change at 300 hz. This is an area that still has my interest, something special might add balance and make thermal drift go away. For now it is only a whisper I do not quite hear. )-:

I have always considered the analog theremin organic and now it becomes more fluid because of water from a crystal fountain that whispers to the roses. 

Construction:

1. Start with a 5/8" o.d. clear plastic tube about 24" or longer for mounting. You can purchase 7/16" #0 rubber stopper at Lowes. Stoppers or corks work but the imaginative will come up with a better approach. Replace the wing nut with a nut.

2. Use a wire 18” to 20"  #22 gauge stretched out loosely inside a plastic 20" tube or a bit longer for a length practical to mount,  keep it dry for now. I connected the wire to a nail I shoved through a small hole I drilled in the rubber stopper. Drilling rubber is not encouraged, it can be a pain.

Piano wire seems ideal but this needs testing as I used enamel coated wire. The ends are in contact with the water.

3. Attach this plastic tube construction as your antenna replacement to your model of theremin. You could mount the antenna temporarily on a narrow board that stands up from the floor. Adjust the proper IF transformer frequency, properly tune your theremin back to Null. The octave count will be minimal with this first test.

My method of measuring the audio frequency is done by using my sound card and this free Pitch Tuner.  Download   345kb

At Amazon: Clear Plastic Tube - 5/8" x 36"   7/16" i.d. Rubber Stopper  #0 size 1/2" x 5/8" For quick removal use the screw with a nut for temporary circuit contact. Water Pearls - Polymer gel beads or use Orbeez Orbeez can be found at most Toy Stores I used seven small packs of 150 beads, way too many. Clear Plastic Tube  Linen & Things Mounting Brackets  Lowes Piano wire or #22 gauge - enamel coated.

Make a written note of your first audio frequency range using a dry wire response, compare this later after the non-toxic electrolytic is added to the 5/8" od. clear plastic tube in the step #4.  I only had two linear octaves in a very small pitch field using a dry wire.

4. The Electrolytic: 1-1/2 cup of clean water with one plastic teaspoon of white vinegar. Pour this into the electrode/antenna plastic tube about an 1" above the center electrode wire. There is nothing critical about this electrode/antenna design except water leakage, so be careful. 

With this water mix added to the electrode/antenna attached to your theremin, adjust the proper IF transformer (L6) frequency back to Null. The octave range now develops out like normal but linear, reach into it and be surprised. Make a written note of the audio frequency range and response, then compare to the original dry measurement.

At this point without adding the gel beads you will experience a Perfectly Linear Pitch Field. Use protection to keep water from splashing on your theremin. I might be reluctant to try this water electrode/antenna on my tube/valve hybrid theremin, but I would. LOL

5. Next is to add the gel beads. Maybe do most of the bead swelling in a bowl of electrolytic water mix for two hours minimum before you place them in the plastic tube, use a funnel. If you add them directly from the package you will have to keep shaking them up to evenly spread them as they swell in the plastic electrode/antenna tube. An opaque tube will block your view of even gel bead distribution. Allow the finale expansion of the gel beads in the plastic tube to continue overnight. The gel beads help add stability and prevent the plastic tube from completely draining if there is water leakage. Sealed properly it should last a long time before it needs to be water replenished.

Initial experiments hint the EtherWave Standard electrode should be double this setup in length as it seems to confirm that Lev's Antenna is a tuned event. Visit here   More construction methods found there.

The Theremin Concept is Perfect: To mimic any part digitally admits failure in the designers understanding and completely misses the point. Naturally the instrument can be drift free, have perfect pitch field linearity and a voice that would get Clara Rockmore's attention. This is not an exaggeration!  "True Beauty is Hidden in Simplicity"

For a clearer understanding of the Meaning of Perfect.