Pitch Linearization Coil Sanity Check

Greg,

These results do look quite impressive - Particularly for a theremin which has no equalizing inductance.

I have some reservations due to the problems you are expieriencing [human-ground] as the capacitive relationships between ground / antenna are critical for accurate measurement of linearity - so at this stage I cannot be sure if these results are due to the LEV antenna or due to some other effects..

But they do look quite good.

What would be really interesting would be a comparison between the best LEV antenna result / settings, and if you then swap the LEV antenna for a tube giving the same capacitive area (as in, replace the LEV antenna with a tube which does not require re-tuning of the theremin.. perhaps a plastic tube with some aluminium tape round it, which you can peel to get the right capacitance)

But whatever - All real interesting..

Fred.

ps - I love your "lab"! - It fills me with envy ;-) .. I had about 2 sq metres in which to build and test my theremins - with final work being timed to co-incide with when my wife was out of the house, so I could use the kitchen.. and be damn sure everything was tidy and clean (as in, she didnt know I had used the kitchen) by the time she got home...

Fred wrote:

ps - I love your "lab"! - It fills me with envy ;-) .. I had about 2 sq metres in which to build and test my theremins - with final work being timed to co-incide with when my wife was out of the house, so I could use the kitchen.. and be damn sure everything was tidy and clean (as in, she didnt know I had used the kitchen) by the time she got home...

Hell, Fred... are or were you married to a dragon???

As Christopher has linked to this page, I need to clarify my posiotion on this matter, and my opinion on the "Lev" antenna - It could otherwise perhaps appear that I am endorsing this antenna, which I am NOT! :

The only conclusion which can be drawn from this thread and the MANY other attempts at verifying the "Lev Antenna" is that THERE IS ABSOLUTELY NOTHING FROM ANY RESULTS which in ANY WAY confirms or verifies or even gives reason for any notion that the so-called "Lev antenna" confers ANY advantage or improvement in linearity.. This thread was just one of a few where the antenna was explored -

It also needs to be stated that the name "Lev Antenna" is utterly and entirely misleading - There is no record that Lev Theremin EVER used this antenna or any variation of this idea or any spiral or spring antenna of any kind..

A Spring / Spiral antenna used on a theremin is NOT a "Lev antenna" - Its a "Christopher Antenna" -

There is (as far as every engineer who has examined it can tell) no science behind its operation, and despite being explored and tested since at least 2005 by many independent constructors, there has not been ONE set of data produced which confirms Christophers claims, and there has not been a single well known precision thereminist who has endorsed it.

It might work - but I have never got it to work, Other than Christopher, I have only heard one person - a hobbyist who cannot play even a simple tune on the theremin endorse it.

I believe it highly likely that the so-called "Lev antenna" is a con, its as simple as that - I may be wrong, but my personal advice to anyone is this: Only explore the Lev antenna if you are really interested in exploring "mysteries" and have the time and patience to do so - and keep in mind that it may just be a fiction ... IMO, Dont bother with it if you just want a linear theremin to play - because I believe you are highly likely to be wasting your time and will end up dissapointed.

And If you do find that I am wrong, Please present this in detail here! - A full disclosure of measured pitch <-> distance and frequencies etc.. ie, the conditions by which you got the antenna to give linearity, would be great!

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 Fred.