AETHERPHON, global theremin family

Quoting David Vanhorn <dvanhorn@...>:

>
>
>   >I think it would be very interesting to see a 3D plot of the capacitance
>   >field of the theremin, with those tuning setting superimposed on it.
>
> That would be a big project.  Lots of data points to collect, and 
> rather difficult.
>
> The first thing, is to discard the idea that the "antennas" are 
> acting as antennas.  They are capacitor plates. At these low 
> frequencies they aren't anywhere near long enough, and the fact that 
> diameter is as important as length confirms this.

We tend to think that a given distance between one's hand and the pitch 
antenna
is produces a given pitch (let's call this the x-axis).  However, the hand's
up-down position (the y-axis) also effects the pitch.

Playability increases when the antenna's sensitivity along the y-axis is
minimal.  In fact, this issue may be more fundamental to playability than
linearity.  That is, if a Theremin has great linearity but is overly sensitive
on the y-axis, then it is still difficult hit notes precisely.

When I replaced my stock Tmax antenna with a longer and thicker antenna (a
chrome plated pipe), the playability increased because the sensitivity along
the y-axis decreased.  The linearity might have been improved a little, 
but the
big advantage was to have less sensitivity to up-down motion.

Has anyone looked in to the up-down (y-axis) sensitivity issue?