Wine Box Theremin Build

I'm so funny!#$%

In theremin design we have no restrictions on home built personal designs. Why is this theremin using 172 MHz?  Also what I have noticed is that I run my theremins 922 MHz and they have the same sensitivity as a theremin at 286 kHz, there are no extra octaves in the pitch field even though I am at triple the frequency.

Breaker Breaker - Reminiscing CB Radios got me upset.

There is the possibility that by definition I did not design a theremin as I never looked at how anyone would make one, including Lev Sergeyevich or Robert Moog.I would need a Pro to evaluate my research or else call it something original, I need to come up with some original name, how about a Christopherin. (-'

Me

@Chobbs

Oh no, replacing parts is just an idea for when it comes to later stages. At the minute I'm only breadboarding the individual circuits exactly as they are drawn. 

I have been in contact Adrian Bontenbal (who wrote the word doc associated with the design) & he mentioned that his one works to this day.

@Christopher

When you say it could be simplified & get the same results, how do you mean? As you can imagine, any simpler option would be preferable!

Appreciate all the input lads!

Conor,

You have been invited onto the theremin journey. Discovery is what it is all about. The first step is to build any theremin so you can appreciate how simply complex a theremin is. That's what we call a oxymoron, how many have showed up saying how easy theremin design is only to quietly fade away.

I have help many students build there working models, after they get the grade they also fade away.

Do you have sound samples of the model from the original designer you are building, I can tell almost everything about the design by looking at the audio waveform in Audacity. Background noise I use another technique which Fred helped me with a while back. I had no idea I had noise in my sound samples, I always thought everyone was kidding me.

The most difficult aspect of the theremin design for me was figuring out how a fat or mature sound came about.

Christopher

Edit: Conor do you have soldering skills also the oscillator section of a theremin can act up when bread-boarded poorly.

Christopher

Sadly I don't, sound/video samples were actually the original reason I contacted Adrian but he said he doesn't have any. I would ask him again but I've already asked for lots of pictures/info so I don't really want to be bothering him. Maybe I should ask if he would be willing to record some samples though. 

Also, in regards to one of your earlier replies, the reason for the four series inductors in the variable pitch osc. is to " improve the linearity of the relationship between the player's hand position and pitch. Without these components, the Theremin pitch would rise slowly at first and then suddenly rise through several octaves in just a few millimetres of hand movement, making the instrument difficult to play"

That's a quote from the strangeapparatus site but I don't know how much of that is true. 

Conor,

there are good reasons why that " quote from the strangeapparatus site " has the potential for truth - Its (at least one of the ways) that Lev got his theremins linear.. But, IMO, its only true IF this technique is done correctly.. And to do it correctly one needs to fully understand it or be extremely lucky! IMO, the quality of Lev's designs, his genius, his in depth intrinsic understanding of physics and mathematics and electronics, well - we havent had any designer who is comparable since him.. This is not hero worship, I think that in many areas Lev was a complete nutter - But in my mind there is no question that his theremin front end design was pure brilliance..

At this point I would personally advise you to coldly look at your objectives - Are you setting out on a "journey" or are you building a theremin with the primary objective being getting good marks on your assignment ? ... My feeling is that you may be better off if you dont get too distracted by issues right now - get your chosen design to work, get your assignment in, then you are free to explore deeper issues if you choose..... Everyone advising you here has been on some kind of "journey" that has lasted years so far..

There are simpler designs - these generally are theremins that dont have any inductors connected to the antenna - they use antenna / hand capacitance directly as capacitance affecting the variable oscillators tank.. Probably the easiest of these are the Silicon Chip theremins - and this article and the links therein is a great version of this.

Thierry gave the best full description of how antenna equalization works that I have ever read - but I cannot locate it! - IMO it should be extracted and turned into a .pdf, and put in the technical repository here!

I am now leaving this thread, as I have no apetite for another "debate" on this matter. I sincerely wish you luck whatever route you choose whether it becomes a "journey" or not - in truth, I think sometimes "journey" is a nicer way of saying "obsession".

Fred.

FredM wrote:

Thierry gave the best full description of how antenna equalization works that I have ever read - but I cannot locate it! - IMO it should be extracted and turned into a .pdf, and put in the technical repository here!

Here it is: on my public Dropbox

Thank you Thierry -

Reading it again I remain of the conviction that this is by far the best and most concise description I have ever found - At that time I had drafted something similat - it was twice the length and half the depth (no maths ;-) but your account is clear even if one ignores the maths..

A masterpiece! And particularly impressive as your native language is not English!

Fred.