About Jaycar's Theremin

Posted: 2/1/2006 2:02:55 PM
flacus

From: Buenos Aires

Joined: 1/30/2006


Can anyone out there take a look at the RF Coils in this kit and tell me what they look like? Values/ manufacturer/partnumber/anything/a picture? (for all four of them)

I need to buy only those, but I could not get any specs about them.

Thanks a Lot. Oscar.
Posted: 2/3/2006 1:27:00 PM
flacus

From: Buenos Aires

Joined: 1/30/2006


OK.
"someone" gave me the answer.
Thank you, A.
Just in case anyone has the same query:

T1, T2, T3 = 2nd IF coil (DSE L0260 white)
T4 = 3rd IF coil (DSE L0260 black)

Mouser Stock Number 42IF202,
2nd Intermediate Frequency Transformer
for 455kHz applications

Mouser Stock Number 42IF203,
3rd Intermediate Frequency Transformer
for 455kHz applications

From www.mouser.com

Posted: 2/9/2006 7:07:13 PM
mathflan

From: FRANCE

Joined: 3/25/2005

Hi,

If You have a distortion on the sound when you increase the volume just put a 1 k resistor between pin 6 of LM358 and Ground, that remove completly the buzz.

Posted: 2/9/2006 7:07:20 PM
mathflan

From: FRANCE

Joined: 3/25/2005

Hi,

If You have a distortion on the sound when you increase the volume just put a 1 k resistor between pin 6 of LM358 and Ground, that remove completly the buzz.

Posted: 3/14/2006 9:01:47 AM
Scratch

From: Bristol UK

Joined: 3/2/2006

Hi everyone, nice forum. I've just finished building my Jaycar theremin. The volume control works OK and I'm getting a tone but I'm getting nothing from the antenna. This of course means I have no pitch control. I've done all the usual solder checks etc and it all looks good. Could I have a faulty IC? Any advice gratefully received.
Posted: 3/14/2006 11:49:26 PM
flacus

From: Buenos Aires

Joined: 1/30/2006


Bad IC is very unlikely. (unless destroyed during assembly, also very unlikely).

With the very few symptoms described, I would say you need to spend some time tuning T1 and T2. If they are too far appart, no matter what you do with the antenna you will always hear the same high pitch tone. Be delicate and patient.

If you have an oscilloscope, write back and I'll describe what you should see.
Posted: 3/29/2006 3:33:39 AM
khbs

Joined: 3/29/2006

Hi everyone, I'm very new to all this - I just assembled my Jaycar kit theremin and am amazed I actually get a sound, considering the most I've ever done before electrically is wiring plugs. But I'm finding tuning very difficult, I can't get much range in either pitch or volume - does anyone have any tips? I don't understand anything about how to check voltages either, do I need to get some special equipment? Also the tuning changes a lot if I put the lid on, but there's no way to alter things without taking it off again - they said there was a hole to adjust VR2 but there isn't , should I drill one?
Posted: 4/6/2006 11:32:25 PM
Jason

From: Sammamish, Washington

Joined: 2/13/2005

There are some tips for improving the Jaycar theremin on our schematics page (http://www.thereminworld.com/schematics.asp). Hope this helps!

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