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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Dec 26, 2016 5:06 pm Post subject:
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Looking good Les. I have started doing some VCA tests on the single transistor VCA.
It would be a very easy module build. But it is pretty noisy. May try to send you a sample audio of it tomorrow after work.
Am about exhausted after work today.
I have been toying with etching for a while. This would be a good first project to try it out on.
If we had solder board versions mapped out and available for each module, that could be nice. What do you think?
I really need to learn to use the computer to map boards anyway. |
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Inventor
Stream Operator

Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Mon Dec 26, 2016 10:51 pm Post subject:
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AlanP wrote: | Ahhhh, now I see what you are driving at
This is a very, very clever way of working around the problem of not being able to solder in your living situation, Les  |
Thank you for chiming in on this thread - yes, I am nothing if not clever! I have since figured (well, re-figured) out that I can get a "cold" soldering iron for this purpose. It is very safe. Still, this is worth doing if only for the exercise of doing it! I figure some customers will want this, and we can offer our flagship model, the VCO, in solder and non-solder versions.
Les _________________ "Let's make noise for peace." - Kijjaz |
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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Tue Dec 27, 2016 6:22 am Post subject:
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I should be ready to try my hand at etching VCO boards this weekend.
Will document the method I came up with in a video.
Really didn't want to buy anything new just to try it. So we will see |
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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Wed Dec 28, 2016 5:53 am Post subject:
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Could switch to a TL074
Ad a comparator and get PWM with the extra 2 opamps.
Never tried PWM from a saw wave.
I can't think of a reason that it wouldn't work ok. Shifting the comparator reference voltage would change the puls width.
???????? Any thoughts anyone??????
I like the simple EFM version, but it has a lot of limitations
I have never seen anyone use a UJT core on a VCO of any quality.
May be a good reason for that. May not. |
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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Wed Dec 28, 2016 6:12 am Post subject:
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Just came to the realization that the little UJTs I like and the woman I loved both have a little saw shaped heartbeat.
Coincidence??? Probably not 😜 |
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Inventor
Stream Operator

Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Wed Dec 28, 2016 7:38 pm Post subject:
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Funny, funny... _________________ "Let's make noise for peace." - Kijjaz |
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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Wed Dec 28, 2016 8:49 pm Post subject:
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So I commented earlier about not seeing a vco schematic with good temperature compensation using a UJT core.
Turns out there is a guy over on muffs working on one too.
LOL what's the odds of 2 guys trying to perfect a vco using outdated UJT transistors at the same time?
I don't feel so alone in the world. |
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Inventor
Stream Operator

Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Thu Dec 29, 2016 12:53 am Post subject:
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Are you comparing notes with him?
Les _________________ "Let's make noise for peace." - Kijjaz |
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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Thu Dec 29, 2016 5:41 am Post subject:
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No Les, I actually made a conscious decision not to read beyond the beginning of his poste.
I would like to see where that section of working with the VCO design goes for me.
Then compare end results with his end results.
Will be interesting to see how similar the end results are.
As they say, there is more than one way to skin a cat.
I'm not a cat lover, so I prefer the straight forward get it done and ccck it method. LOL. |
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Cfish

Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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