Goals for a TW Theremin

Posted: 10/29/2014 3:39:26 PM

From: Northern NJ, USA

Joined: 2/17/2012

"...are essential on that Clapp?"  - FredM

Yes, on the bench anyway, and with the inductors I'm using.

Just tried it with a smaller air core and am not seeing oscillation.  Wonder if it is the large resistances magnifying stray capacitance?

[EDIT] In light of this I think I'll stick with FETs.  I also tried a Colpitts version of this ala livio's Theremino and it oscillates with a single large coil but it stalls when the antenna is grasped and the antenna voltage swing is lower.  To save money on coils, and space on the PWB, one could I suppose use a Clapp for the variable oscillator and a Colpitts for the fixed oscillator.

Posted: 10/29/2014 5:34:51 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Dewster said: “ do you have an explanation of how the fine tuning control circuit works on the EWS? I'm looking at the schematic but it's eluding me. . .”

Fred said: “But as I say, I don’t know why there seems to be improvement for linearity (but never good linearity) for simpler designs when the frequency is higher”

Gentlemen welcome to my latest design called returning to “Tube Warmth.”

* These are my answers below to the above questions, why do you say TROLL. . . punk?

A girl with a discouraging attitude would be a punk'en, this time of year maybe a witch?

I operate at 922khz which for ten years has shown the best Pitch linearity.

Varying the voltage across the Osc circuit does the tuning on a solid-state oscillator, the transistor behaves like a varactor naturally. The circuit needs less than a 2-volt change with a circuit current of about 2 ma.  This always amazed me that the Pitch antenna had sensitivity out greater than 2-meters.

A little hint: The more sensitive a transistor is to this affect the more sensitive it is to thermal drift. (-‘

Warning, my journey is about learning electronics. I do not need a long colorful rant about my poor use of electronic terms from a self-absorbed mindless punk!  Step forward if the compulsion overwhelms you.

The Tube Warmth Altermen or TWA is about rising above the clouds. Her flight arrives in 2015.

Edit: That is a harsh word, I apologize and changed it. So you moved earlier this year, to East Orange? By the way you still owe me $50.  0-:


Posted: 10/29/2014 5:42:49 PM

From: Northern NJ, USA

Joined: 2/17/2012

"I do not need a long colorful rant about my poor use of electronic terms from a self-absorbed mindless prick!  Step forward if the compulsion overwhelms you."  - RS Theremin

TW needs a "troll" button.

Posted: 10/30/2014 4:59:51 AM

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

"TW needs a "troll" button." - Dewster.

TW needs to eject the troll .. Its as simple as that.  The TW theremin project was smashed up by this same troll last time.. and he announced his "TW theremin" (branding it "Thereminist Warrior") - Now, a day into this thread re-starting, theres his announcement of the "TWA" theremin from him and a bucket of abuse. This troll flagrantly uses TW and its 'logo' to (attempt to) give himself credibility, and posts out-of-context snippets of peoples posts on TW on his web site.

But I am now too tired and fed up to bother drawing attention to his derisive activities - If TW doesn't want to  do anything about the disruption he creates, so be it..

I feared getting onto this thread for exactly the reason that if I was participating I expected a repeat performance of last time - but actually, its not just me he's after - he doesn't want anyone who isn't in his secret club and subservient to his "greater insights", to develop anything.

Him and his sock puppets are the scourge of TW, and they attempt to recruit newcomers in particular, or target technical threads they are likely to be most interested in.

TW does have a "report post" button. Use it!

I took on the matter last time and fought the troll, but got the opposite of any thanks for doing so .. I dont give a shit this time, let the troll rampage for all I care.. While he is a member of TW I  wont be contributing anything to this thread, and I cant even be bothered to click 'report'.

I am also removing the posts I made here this week. Yes - an act of protest if you like.. And what with the theremini saga and this, I have just about had it - taking an indefinite break.


changed my mind about removing the posts - if I do that, folks may think I did something to provoke the troll..

Posted: 10/30/2014 4:07:45 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Gentlemen let me first say “I do feel the love”.

On November 3, I will surrender the avatar RS Theremin. That mystical journey accomplished what was necessary and now it's success is up to certain individuals if it is to reach full realization. If time allows I will reintroduce myself as oldtemecula as the rest of the Internet identifies me.

I have designed a single tube/valve theremin-like DIY design that people of the World have been waiting for. The tube creates a fatter sound as heard in my many sound demonstrations. The solid-state section allows for the use of easily obtained modern day components. Nothing fancy, just what you expect from an authentic theremin.

I call it the Altermen (Alternative Theremin) but could it be All-Termen? He did live until his passing in 1993.

Like the Theremini there will be some who are unable to accept the fact that one of the 20 active theremin enthusiast might find this interesting. There are still some kinks to work out and it is disappointing to me we no longer have designers with the practical hands on knowledge I need or can count on at TW.

Please no comments from other Clowns.


Posted: 10/30/2014 5:20:22 PM

From: In between the Pitch and Volume hand ~ New England

Joined: 12/17/2010

I am not a clown, but a witch, so I guess I can comment!

Seriously though, with all the "warm and fuzzies" I feel when I come here and read this thread on occasion only confrim why I don't really comment much on this thread...


Posted: 10/30/2014 8:33:31 PM

From: Northern NJ, USA

Joined: 2/17/2012

In general I think large resistances in an oscillator are a bad thing as the larger are the more Johnson noise they generate, and the more they contribute to stray RC and other delays.

Posted: 10/30/2014 10:42:02 PM

From: germany, kiel

Joined: 5/10/2007

Well, i just can double Ameys posting. And further on i can say, that nothing really comes to an end on TW (concerning the technical stuff). Mostly it´s subjunctively: this and that could do this and that, will incorporate this and that in my new design and so on. But: nothing for years. What i´d like to read about if i were about to build something would be real experiences with really build up and documented circuits, not simulations and stuff. For sure that´s not interesting for people peeking here, nor it´s interesting becoming involved with the embarrassing and reiterative fights between certain members knowing how to trigger each other. Yes Christopher, a riddle what you are after. You posted the worst sounding sound examples – be it musically be it technically, not being able to hear bad signal modulations and proclaim yours to be kind of best. Dewster once called me a "wannabe designer". Never proclaimed to be a "designer". And with Fred it´s all theoretically. Every single day new ideas with no follow-up. I wanted to encourage you to come out with something cause there are definitively bad theremins which unfortunately sell well.. and cause you were always talking about something going to market. After that you once more declared to leave TW and got back in about a few days like you use to do. Oh man, sorry guys, i seem to be in a bad mood, though i think i am right. Not THE contributor but a reader and loving the experiment it´s me now saying to invest no more time here.

Posted: 10/30/2014 11:20:47 PM

From: Northern NJ, USA

Joined: 2/17/2012

"Dewster once called me a "wannabe designer""  - DOMINIK

Gosh Dominik, "this wannabe designer" was a reference to myself, not to you.  I'm sorry you misunderstood, I have no possible reason to dis you.

You have a good point in that it must get tedious for people reading the technical ideas threads to never see real fruit in the marketplace.  Personally it's taken me years of thinking about this stuff, simulating, and benching physical circuits, to really grasp what is going on and how to best implement things.  I have a feeling that's how other developers are functioning as well, where the better is the enemy of the good, and actually going to market is a huge hurdle.  I'm enjoying being on what feels like on the other side of things, but there are fundamentals that still elude me and make me uncomfortable.

I started out on element14 and I was cautioned against taking the technical discussion to TW, but here I am driving everyone crazy with too many posts.  What to do?  I just hope people who are turned off by me avoid  reading my posts.  I do feel that in my own small way I've helped push the theoretical and practical digital aspects of Theremin design forward somewhat.  But without Fred's voluminous knowledge I'd be at square one.  TW is really lucky to have him here, and I wish people wouldn't try to push his buttons.  He took one for the team and should be given more respect.  IMO, the best designs will be modern, well engineered ones, firmly grounded in reality, yet taking all esthetical and player oriented elements into account.  The best of all worlds really.

Posted: 10/30/2014 11:59:29 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

Dominik we go way back and you were always one of my favorites in my early designs on my learning curve. I am happy I got to meet you and dewster early on. I am just a hobbyist and never claimed to be more. If my sound bytes were offensive it is because I am deaf, which a few here are aware of. It forced me to rely on TW members for feedback. As you know what is beautiful in sound cannot be recognized on an oscilloscope screen, but I have learned what looks most appropriate. I admire your work and what you have accomplished.

Visit early Dominik


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