while my electronics abilities are
adequate, i still have several limitations:
1) time
2) climbing impatience
3) inability to pay attention to stuff and remain interested in things for extended periods
4) inadequate parts suppliers in the cache valley area
5) the knowledge that theremins can be temperamental and difficult to design
So, for my first theremin, I decided to first follow the instructions and plans and advice presented by christpoher at:
http://www.oldtemecula.com/theremin
check out the site, it is very informative for those unfamiliar with this musical instrument.
I am building the RS theremin, and the "RS" stands for "Radio shack" That means, all components are available at the mentioned store, which I have access to. As i learn more about theremins, I will experiment with different modifications to the design. Right now, i am most interested in just getting a voice.
Progress so far:
check out the photos of my completed etched circuit board!!!
here are the completed coils, ready to mount.
here is a mostly completed circuit, complete with coils. I could not find any 100pf capacitors at my local radio shack, so I bought the variety pack, and still came up with no 100pf capacitors. I instead substituted 150pf capacitors, and it the theremin sings!!
first oscillator test audio file
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1) time
2) climbing impatience
3) inability to pay attention to stuff and remain interested in things for extended periods
4) inadequate parts suppliers in the cache valley area
5) the knowledge that theremins can be temperamental and difficult to design
So, for my first theremin, I decided to first follow the instructions and plans and advice presented by christpoher at:
http://www.oldtemecula.com/theremin
check out the site, it is very informative for those unfamiliar with this musical instrument.
I am building the RS theremin, and the "RS" stands for "Radio shack" That means, all components are available at the mentioned store, which I have access to. As i learn more about theremins, I will experiment with different modifications to the design. Right now, i am most interested in just getting a voice.
Progress so far:
check out the photos of my completed etched circuit board!!!
here are the completed coils, ready to mount.
here is a mostly completed circuit, complete with coils. I could not find any 100pf capacitors at my local radio shack, so I bought the variety pack, and still came up with no 100pf capacitors. I instead substituted 150pf capacitors, and it the theremin sings!!
first oscillator test audio file
right now, it will make a noise over an
AM radio, good enough to test
and tune the coils. Everything sounds like it is working suitably
at this stage. I still need to hook up an audio output, finish
installing components, and building an antenna. I am considering
different approaches for mounting the instrument. I have been
offered a rough end table from Anna and Mo's farm, but it may be a
little more bulky than I want. I'll keep checking dumpsters
and the DI for suitable tables or wooden boxes.
Update: 10/5/05 - it seems like
the old 555 IC I have had laying around for over 10 years is either
bad, or will not work with this circuit. I completed the circuit,
attached a makeshift antenna from an old television, plugged the unit
into an amp, and only got a weak signal. I swapped out the 555
for another 555 I had in my parts box, and the theremin performed
differently, but still not correctly. Now I notice I am using an
NE555 rather than the specified TLC555. Although they are similar
chip and do basically the same thing, the TLC555 is a CMOS chip and
uses about 1/120th the current... I'll get the correct part
tonight and have fun.
10/6/05 - I bought a TLC555 chip last night from radio shack for a buck ninety five. This new CMOS circuit should use much less power than the old NE555 that I was using. The results were not what I expected. I get a signal that I can modulate with my hand near the antenna, but the entire range of pitch is achieved by moving my hand only about 5 cm. The pitch also seems way too high, and the signal-to-noise ratio is very low. Recall i substituted 150pf capacitors for 100pf. I need to order some toggle witches for another project, and I'll order in some correct 100pf capacitors for the theremin at the same time. I also may have a problem with the antenna. Right now I am using an old teevee antenna taped to a wire. Some of the noise may come from that arrangement.
One very curious devilment I have noticed is that if I touch the antenna, I can hear a radio station. In other words, the theremin is acting as a radio - more on that in a bit. The radio station I receive is weird. I am thinking I am receiving a secret underground communist radio station. This may be related to the secret communist military base I discovered in granite wash, arizona, and again near big creek, utah, last weekend.
But why am I hearing a radio station? I am not yet an expert on theremin theory, or the circuit I am building, but considering the basic physics of a theremin, receiving a radio signal is not unexpected. Think of a theremin as a radio station and a radio receiver built into one package. It is broadcasting a weak electromagnetic field (radio signal) and then receiving that field through an antenna, and amplifying it as an audible sound. At least, that is how I think it works. The part of me that comes up with crazy theories like that is surely genetic. in other words, my physics may not actually match the true physics of the situation. When I touch the antenna, I change the frequency of the oscillator, and receive a different frequency, coincidentally corresponding to the frequency of the communist radio station.
Perhaps this theremin phenomena and my modulation of EMFs in my house is causing my weird dreams as of late. If you haven't heard the stories of my weird dreams, it is probably best you stay away from that subject. I've also lost most of the concept of time. This may also have to do with EMFs.
anyway, here are some update photos:
the theremin still in experimental stage, sitting on a cardboard box. I've replaced the output wire with a shielded wire. This cut the noise in half. I have also repositioned coil L1, without any change in results.
10/6/05 - I bought a TLC555 chip last night from radio shack for a buck ninety five. This new CMOS circuit should use much less power than the old NE555 that I was using. The results were not what I expected. I get a signal that I can modulate with my hand near the antenna, but the entire range of pitch is achieved by moving my hand only about 5 cm. The pitch also seems way too high, and the signal-to-noise ratio is very low. Recall i substituted 150pf capacitors for 100pf. I need to order some toggle witches for another project, and I'll order in some correct 100pf capacitors for the theremin at the same time. I also may have a problem with the antenna. Right now I am using an old teevee antenna taped to a wire. Some of the noise may come from that arrangement.
One very curious devilment I have noticed is that if I touch the antenna, I can hear a radio station. In other words, the theremin is acting as a radio - more on that in a bit. The radio station I receive is weird. I am thinking I am receiving a secret underground communist radio station. This may be related to the secret communist military base I discovered in granite wash, arizona, and again near big creek, utah, last weekend.
But why am I hearing a radio station? I am not yet an expert on theremin theory, or the circuit I am building, but considering the basic physics of a theremin, receiving a radio signal is not unexpected. Think of a theremin as a radio station and a radio receiver built into one package. It is broadcasting a weak electromagnetic field (radio signal) and then receiving that field through an antenna, and amplifying it as an audible sound. At least, that is how I think it works. The part of me that comes up with crazy theories like that is surely genetic. in other words, my physics may not actually match the true physics of the situation. When I touch the antenna, I change the frequency of the oscillator, and receive a different frequency, coincidentally corresponding to the frequency of the communist radio station.
Perhaps this theremin phenomena and my modulation of EMFs in my house is causing my weird dreams as of late. If you haven't heard the stories of my weird dreams, it is probably best you stay away from that subject. I've also lost most of the concept of time. This may also have to do with EMFs.
anyway, here are some update photos:
the theremin still in experimental stage, sitting on a cardboard box. I've replaced the output wire with a shielded wire. This cut the noise in half. I have also repositioned coil L1, without any change in results.
Here is an amplifier I built about 5 or
6 years ago, and never got working like I wanted. Again, I have a
noise problem, that I think I know how to solve. I installed a
second filtering capacitor on the power supply, and later I will add a
better ground to the transformer and replace some wires with shielded
speaker wire. This will be my primary amp for the theremin,
when I eventually get an acceptable sound.
10/19/05 - time to update some recent progress, eh? I found the perfect table to house my instrument, in my very own carhold! Turns out the table belonged to Debi, and she let me have it. It is in rough, VERY ROUGH, rickety shape, but a little wood glue, some screws, and some purple paint and it will look nice. I have mounted the circuit board and coils underneath, built and attached an antenna to the top and am slowly creating a piece of interest.
The problem - it still does not work well! I discovered my school has an "EE stores" where I can buy all sorts of electronic gizmos. I tried to get 100pf capacitors, but the closest I could find was 110. I installed the 110pf capacitors in place of the 150pf that I was using, and there was little improvement. I am not getting weird radio stations any more, but the sound is still way too quiet, and static and noise seems to overwhelm the signal. I have a few ideas what may be wrong - but without a multimeter, testing will be difficult. So, if anyone wants to get me a birthday gift :)
here a picture of what I have so far, taken in natural light in the morning. You can see the state of my "studio" in this photo - still with that old "beth" teevee and the cabinet I built.
10/19/05 - time to update some recent progress, eh? I found the perfect table to house my instrument, in my very own carhold! Turns out the table belonged to Debi, and she let me have it. It is in rough, VERY ROUGH, rickety shape, but a little wood glue, some screws, and some purple paint and it will look nice. I have mounted the circuit board and coils underneath, built and attached an antenna to the top and am slowly creating a piece of interest.
The problem - it still does not work well! I discovered my school has an "EE stores" where I can buy all sorts of electronic gizmos. I tried to get 100pf capacitors, but the closest I could find was 110. I installed the 110pf capacitors in place of the 150pf that I was using, and there was little improvement. I am not getting weird radio stations any more, but the sound is still way too quiet, and static and noise seems to overwhelm the signal. I have a few ideas what may be wrong - but without a multimeter, testing will be difficult. So, if anyone wants to get me a birthday gift :)
here a picture of what I have so far, taken in natural light in the morning. You can see the state of my "studio" in this photo - still with that old "beth" teevee and the cabinet I built.
10/22/05 - sometimes you get
lucky. After thinking for a few days why my theremin wasn’t
working, I decided I wasn’t going to learn much without a
multimeter. Smittys (freddies) sells an analog one for 12
bucks. Perfect. I soon tested the voltage across my
transistors and decided one was low. Then I read the number on
the side of the transistor. Damn. I was using two different
types. I had assumed the pack I had bought was all the same type,
but I was wrong. I quickly swapped out the proper transistor,
and… the damn thing still didn’t work right!!! I tried tuning the
oscillators again to the AM radio – worked awesome. I plugged
back in the ICs = no gold. In my haste, I fiddled with the wires
to one of the coils, and broke one off. Damn. I guess I
would have to re-wrap it.
after 30 minutes of smoking a pipe and drinking whiskey on the porch while re-wrapping my coil, I soldered it in place (anticipation now). HOLY SHIT THIS THING SOUNDS AWESOME!!! The antenna is sensing my movement from about 3 feet away! I am intriguing kitties, amusing housemates, and scaring missionaries. Perfect. i spent two hours playing this device on my porch – moving my hands and feet around, beer in one hand, leather furry coat on my back….
AWESOME!!! I’ll record some sounds for you, and post a photo of me on the porch playing...everyone who hears looks and smiles – including myself!
so what’s next (besides the 12 hours of sleep I got the night I got this working)? well, the controls are still all on the board. I’ll build a control panel to hang off the table for an on/off switch, volume and timbre controls. Then the table needs some paint and decoration. Then comes the different voices and volume control circuitry. I’ll be busy for quite a while.
after 30 minutes of smoking a pipe and drinking whiskey on the porch while re-wrapping my coil, I soldered it in place (anticipation now). HOLY SHIT THIS THING SOUNDS AWESOME!!! The antenna is sensing my movement from about 3 feet away! I am intriguing kitties, amusing housemates, and scaring missionaries. Perfect. i spent two hours playing this device on my porch – moving my hands and feet around, beer in one hand, leather furry coat on my back….
AWESOME!!! I’ll record some sounds for you, and post a photo of me on the porch playing...everyone who hears looks and smiles – including myself!
so what’s next (besides the 12 hours of sleep I got the night I got this working)? well, the controls are still all on the board. I’ll build a control panel to hang off the table for an on/off switch, volume and timbre controls. Then the table needs some paint and decoration. Then comes the different voices and volume control circuitry. I’ll be busy for quite a while.
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