# how do you make a theremins range wider

Posted: 10/5/2005 5:47:04 AM

Joined: 10/5/2005

i am trying to increase a theremins range so that it can pick up the movment about 10 meteres away...does any body know how to do this?
Posted: 10/5/2005 7:35:42 AM

From: Hillsborough, NC (USA)

Joined: 2/13/2005

So you're asking about physical range as opposed to increasing the pitch range of a fixed distance? Great question!

My guess is that you'd need to

Here's a website that lets you calculate capacitance for a "plate capacitor":
http://www.woodsbas.demon.co.uk/calcs/permtvty.htm

In this forumla, you want to increase the result, C, as d increases. Since your dialectric is "air", you can't really change that parameter. But you could change the size of the plate (the pitch antenna).

When I moved from the Theremax to the Etherwave, I noticed the latter had a much longer response range. Sometime it's troublesome though, especially on a crowded stage. Remember that the control zone extends in a circular fashion from the pitch antenna in all directions.
Posted: 10/5/2005 2:19:14 PM

Joined: 7/27/2005

Wow! 10 meters!

What kind of space do you have which is big enough to not have other things setting off the theremin? Got a 20 meter diameter empty sphere? Even the floor or the ceiling could have enough capacitance to affect the theremin at those ranges. Not to mention the wiring of the building or the plumbing or the wiring to and from the amp or the amp connections themselves. Perhaps if it was in orbit you could get that much electrically clean space around the theremin.

Since theremins react to whatever is closest to the antenna it may be able to be done if there is nothing closer than 10 meters in any direction...

3 meters is doable in a more normal environment. You may have problems with false triggering tho... And stability issues.

Inquiring minds want to know... Why do you want this?

HTH

Grasshopper
Posted: 11/4/2005 12:33:36 AM

From: Morrisville, PA

Joined: 10/19/2005

I have found that without any internal modifications to the Etherwave at all, I can set the pitch control knob to react to me from about 15 feet away (about four to five metres), sometimes a little more. It's a process of going back and forth by CRAWLING on all fours and coming at the theremin from BELOW so that it doesn't react to you at all, then adjusting the knob, then crawling back out and standing up. I do this about four to five times, getting it to react at increasing distances. Once it's set, it actually works. However, at that distance, your're in the low range, and you'll remain there for about four feet, then as you come closer there's noticeable rise in pitch. I do use this setting often as part of what I do when performing. Ten metres, though, is a tall order.
Posted: 11/4/2005 4:10:38 AM

From: England

Joined: 2/28/2005

My guess is that you'd have to increase the power consumption of the unit somehow.

The Etherwave Pro guzzles up more energy than the standard, and it also has a much larger 'range' around it. I have to get people to stand much farther away when I play my Pro than when I play a standard, and so I daresay that there's some difference in the size of the voltage/intensity being used to induce a field around the antennae.
Posted: 11/4/2005 6:21:47 PM

From: Los Angeles

Joined: 3/8/2005

The range has to do with the capacitance of the antenna and related circuitry. The easiest way to increase the size of the field is to simple put a longer antenna on your theremin. The other way is to add an inline air coil in series with the antenna.

Charlie - the reason the E-Pro has a much bigger range than the standard is because it has several coils in series to the antenna, as well as the pitch arm, which is kind of like a modified coil inside. This is also how the Etherwave achieves such good linearity.

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