Antennae: Longer better?

The Moog Forum Theremin Forum
1

Dear Mr. Moog and people.

The theremine is a great instrument.
Tell me though, kindly, can we put a larger antennae
on the instrument? What happens to the sound? Also
what if we make an antennae a different shape or fabric?
(what of a long bare wire? that can be bent?) Anyway,
thank you Mr. Moog! And also the Project Pimento.
Also what is the best, smoothest, clearest method and device
and medium to record theremine? How is it done?
Thanks again! I am an amature so any technical repiles
will be lost on me!

2

Why fix something if it’s not broken? You can use anything that is conductive for both antennae, although keep in mind that if it gets too close to a ground source (a table, the TV, the floor, the cat, the theremin box itself) it will affect the performance of the instrument. The size and shape of the conductors (antennae) doesn’t really matter, provided you can comfortably operate the sounds. There should be no difference in sound at all.

Lately I’ve taken to playing without fastening either antenna and just move my hands in and out (like I’m playing a large imaginary accordian in space). The sound remains the same, but the actions are different.

Last time I checked, fabric doesn’t conduct much of anything so it wouldn’t make a good antenna. But I imagine if you drape the theremin with fabric, it would continue to function.


I’m quite fond of reel-to-reel tape. Barring that, you could go digital (I highly recomend ProTools) which makes playback and editing quite easy.

3

[quote=“Crash”]
Last time I checked, fabric doesn’t conduct much of anything so it wouldn’t make a good antenna. But I imagine if you drape the theremin with fabric, it would continue to function.[/quote]


I once tried covering my theramin with a special tape that was supposed to only look metalic. Turned out it was metallic and I got no sound from the box. As soon as I pulled the tape off it worked fine.

Recently, I went to a store and got some small diameter, flexible, plastic conduit. I put black over the volume antenna and blue over the pitch antenna. Looks kewl. Works fine.

\

[quote=“Crash”]
[For recording] I’m quite fond of reel-to-reel tape. Barring that, you could go digital (I highly recomend ProTools) which makes playback and editing quite easy.[/quote]

With the low cost and high quality of digital equipment today, I wouldn’t both with tape (although it does have beautiful characteristics). So if the equipment is good, the real challenge is what happens between the theremin and the recording input and what you do with it after you have it recorded.

As a general rule, the shorter the cables the better. Do you have any outboard devices you like to use? My setup is rather simple:
Theremin->octaver->analog stereo delay->stereo into a Mackie mixer->digital recorder (ProTools in my Mac). For output I’m currently using a B52 Matrix 1000. Be sure you have a high quality playback system (mixer, amp, speakers) so you know what it really sounds like. If you playback through crappy $20 amplified speakers chances are good it will sound just as bad when going through a good system…only louder!

4

I’ve been looking at the antenna shape, and I think it does make a difference. The antenna rod acts as a capacitor, and it’s capacitance to “ground” is going to be proportional to it’s surface area (NOT shape!) so as far as the basic tuning goes, no the shape has no interesting properties there.

But, when you bring your hand near the rod, now things change.
Only the part of the rod that is relatively near you hand, actually “sees” your hand. Difficult to express, but as you get closer, the shape of the rod makes a difference.

A flat plate twoard your hand would seem to give the worst control, and a thin edge, the best. I’m off today, to get the supplies to test an antenna made from airfoiled aluminum tubing. If I’m right, pointing the thin edge at the user will help linearize that last octave as you get close to the antenna, and not affect middle or lower ranges at all.

Rotating the tubing would allow you to adjust this to your preference.

This tubing is available in many aircraft hobby stores, in 3’ lengths, for about $5-$7, under the K+S brand name.

For the Etherwave, you’d have to use a short section of 3/8" round tubing to fit the antenna connector, and then connect that to the airfoiled tubing.

Thinking on the original design, if a larger plate or larger diameter antenna rod would have worked better, that would have been easy to do in 1930. However, if thinner rods work better, you come on a problem, in that thinner rods become more flexible. I don’t think airfoiled tubing was much of an option then. It has almost the rigidity of the larger diameter, but can be made to present a relatively small surface area to the player, in the near field.

Anyway, it’s a theory as yet. I’ll know more this afternoon.

5

I should mention, I just posted on this in more detail, on Levnet, with a discussion on finding the “sweet spot” in tuning the pitch osc near, but just above, the antenna’s self-resonant point. It seems to make for better control.

6

Hi,

The shape of the antenna has influence, of course. It changes the form of the electrical field. The same movement of your hands and of your body produce different sounds.

You can use solid metallic coated triangles (for example PCB - printed circuit board - material.)

I tried it with a simple pitch-only theremin. If you are using a very short antenna, you will have difficulties to play it, because of the small spaces between tones.

The sound itself will be the same but the properties of producing it change.

I think, the antenna of the Etherwave Theremin are optimized for quality and easiness of playing.

Do you know the terpistone? It has a special antenna and was played by dancing.

It has a metallic plate as antenna.

http://www.thereminvox.com/article/articleview/17/1/21/

Best regards
Bernd

7

““I should mention, I just posted on this in more detail, on Levnet, …””
Side question:
Where is the Levent forum? All I can find is the form to subscribe to the email list.

re: atenneas, I’ve seen lots of different variations like all of us. Having a Moog EWPro in my hands now I find it is so very playable I tend to trust Moog’s designs and don’t think I’ll mess with it.

Have fun with your threre-venture, it’s a wonderful instrument and the world should know it!

8

Levnet IS an email list! But don’t let the low tech fool you. Levnet is frequented by one of the largest groups of theremin enthusiasts with vast knowlege and experience (and strong opinions). Uh, I’m there too. :wink: