Glasgow Theremin (analogue)

Posted: 3/10/2012 11:10:33 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

I'm sorry, but "Oh Lord, forgive them for they know not what they do" is not part of my religious heritage... :-)))

Posted: 3/11/2012 1:21:20 AM
FredM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

"I'm sorry, but "Oh Lord, forgive them for they know not what they do" is not part of my religious heritage... :-)))"

LOL! ;-)

Hi Thierry.. You could always resort to the fact of determinism (as in, no one is actually responsible for what they do, whether they "know" or not.. and therefore no "forgiveness" is required) and just be grateful that the forces acting on you (in effect, the universe) have made you what you are..

IMO, there is luck - only luck - and we do not make our own luck! ;-)

Oh - one day I may be back to talk about theremins again.. but not yet! ;-)

Posted: 3/11/2012 11:05:36 AM
Thierry

From: Colmar, France

Joined: 12/31/2007

Hi Fred, good to read this "LOL! ;-)" from you, though! :-)

Posted: 3/11/2012 12:47:41 PM
coalport

From: Canada

Joined: 8/1/2008

Freddy! You're back!

We have missed you. Now that you have returned to the theremin fold you must never go away again. 

Posted: 3/11/2012 3:55:59 PM
Flub

Joined: 6/12/2011

okay,

That is really bad that it isnt a working circuit.

glasgow circuit

Posted: 3/11/2012 4:44:52 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Flub,

I do see you’re developing construction skill and focus with lots of determination. Every theremin builder/designer knows the next version is always waiting to be built. Theremins are one of those never ending projects. If designers seem like asshole Drill Sergeants at times, it is because they know the journey is very tough! Most people quit the theremin before they give it a chance, this is what separates the Master Builder or Thereminist from just the ordinary.   I think this is where inspiration selects the few FredM.

My first attempt and for many years sounded mousey, what creates "the big voice" and not that saxophone sound? Today I ask visitors that come to my home what they think of my sound after I play them a recording of Clara Rockmore, they think my sound is awesome or are they tired of me asking? lol

Below is a photo of my first theremin. This crude construction verified the Lev Antenna, could that have been luck?

Anyone that built my earlier work will get a free enigma pcb once they are manufactured. I have emails to verify you so don't cheat... dominik? ( '

First Attempt at Theremins

Posted: 3/11/2012 7:24:27 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

Flub,

when I look at your PCB, I get the impression that you are not too experienced in building RF circuits... This rats nest wiring may be responsible for parasitic capacitances and thus bad working of your circuit.

I allow to suggest that you do as I do: Even for prototyping on raster PCBs I draw the schematic in Eagle, a free layout software and then I optimize by hand the position of the components (with the appropriate 0.1" setting) as if I would create a "true" PCB in order to avoid unnecessary long signal paths or crossings, and in order to separate on the other hand the circuit parts which should not interfere. Thus it is always a good idea to have the voltage regulation and the mixer stage in the center, surrounded by the RF buffer stages on opposite sides, and the oscillators still beyond the buffers to keep them at maximum distance. The individual supply decoupling (100R/47uF) for each may help routing the supply voltage to each side.

Posted: 3/11/2012 7:45:35 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

"IMO, there is luck - only luck - and we do not make our own luck! ;-)"

This reminds me of the Larry Niven SF novel Ringworld where the Puppeteers bred humans for luck.

Posted: 3/11/2012 8:02:36 PM
dewster

From: Northern NJ, USA

Joined: 2/17/2012

My recommendation is to breadboard the oscillator hooked to the pitch antenna and thoroughly examine it with test equipment.  If you can get that working then move on to the rest of the circuit, one thing at a time.  Layout can be critical, though this is quite low frequency RF.

All it takes is on stupid thing to keep your theremin from working.  For example, it took me a long time to figure out how to properly tune my Etherwave Standard - before I got it right it was pretty horrible to play.  Now it's more linear than I ever thought it could be.  Today I hacked in a new mixer - the bass range is extended and smoother sounding!

Posted: 3/11/2012 8:12:25 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

Citation from dewster: "For example, it took me a long time to figure out how to properly tune my Etherwave Standard - before I got it right it was pretty horrible to play.  Now it's more linear than I ever thought it could be.  Today I hacked in a new mixer - the bass range is extended and smoother sounding!"

All that existed already, even without replacing the mixer, just read the first post by GordonC in this thread ...

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