RCA cabient from scratch and help needed on the next steps

Posted: 5/9/2007 5:50:53 PM

From: AZ

Joined: 11/25/2005

The replacement tube arrived!


here's a direct link to the video: video link (http://u.arizona.edu/~mbuffing/livejournal/thereminworking/thereminaudio.mp4)

PK: my solution for the 5 to 4 prong conversion was documented here: http://bedsidestory.livejournal.com/33504.html
Has your Radiola 60 arrived yet?

BA: Thanks! The wait wasn't so bad!

The tone is still weird. I'm assuming it's a bunch of things, mostly the transformer I'm using before my small guitar amp. Eventually I'll get my diamond speaker replica project finished, and get some great sound out of that.

Tuning is still weird. Still have a lot to learn about this machine. Things I have learned about the theremin:

If you tell someone you're building a theremin, there are two possible reactions:
"Huh, what's that?" and "Wow! No way! That is so awesome!"

The next time you see that person, there is only one enthusiastic question (varying slightly depending on the previous reaction) that comes up, usually at the beginning of the conversation:
"How's that... thing... the what's it called, coming along?/How's the theremin coming along?"

It is a miracle that this thing was ever invented. finicky tubes, coils, wire, all at just the right combination... Theremin was a total genius. Like Bob said, "You open up one of Theremin's machines and there's nothing inside. It's all smarts." There is great efficiency of design, both electronically and physically. The wood and the brass parts are just as well thought out and designed as the electronics. Theremin was a very good designer and artist.

I learned that I both hate and love the theremin simultaneously. Often times with varying amounts... almost like the fixed and viable oscillators... hmmm. I should draw this out. I'm onto something.
Posted: 5/10/2007 11:00:34 PM

Joined: 11/5/2006

Brilliant work you've done so far.

I am also building an RCA replica from a Radiola 60, and was hoping you could go back to the machine shop and create a few more sets of antennas. I know I could use two sets myself, and will pay fairly for them.

Also (much easier favor) could you post the image of the radiola 60 PSU that Mark McKeown provided earlier? The link in his post no longer works.

A general warning to others trying to create a theremin from a Radiola 60: Some Radiola 60s -- presumably later versions -- have a slightly different PSU. In the older ones, all the "boxes" are approximately the same height. On later ones, the "box" in front (beside the tube) is quite a bit shorter. I am assuming they either used smaller capacitors or figured out how to get the same capacitance in a smaller space.

Posted: 5/11/2007 12:08:05 AM

From: AZ

Joined: 11/25/2005

PK, the image you're looking for can be found here:

don't forget to short terminals 3&4 and 6&7. Also remember that the numbering of the terminals under the front cap is different, as Mark and I discussed earlier in this thread (though it doesn't change anything in the drawing, really).

Email me about the antenna. I'm still working on a few last things, but should be done soon. mike at mikebuffington dot net. The quality of my antenna sets match that of the only other known replica antenna maker.

I noticed on the pictures of the Radiola auction that you don't have the cover that goes over the terminal strip and voltage selector switch. I could probably make a replica and paint it the color-matched brown.
Posted: 5/11/2007 1:17:13 PM

From: AZ

Joined: 11/25/2005

PK: I redrew the image to include a wire that was missing in the original.

Posted: 6/5/2007 12:50:49 PM

Joined: 10/8/2005


You have done a great job! Your craftmanship is impressive! It is nice to see another RCA made. We could start a new series of serial numbers starting with 300. I have dibs on 300001.


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