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  1. SparkyCal

    The Theremin Stretch

    Thanks. Will try this latter tonight and report back
  2. SparkyCal

    The Theremin Stretch

    Hi...I bought the J110's and popped them in, as well as the 8-40pF capacitor. I am still not getting any sound. However, the new capacitor has three pins and i am not sure I hooked it up correctly. I hooked one of the pins to one side of the 1mH inductor , and the other to ground. I'm not sure...
  3. SparkyCal

    The Theremin Stretch

    Hi Bertus- I am following the breadboarded version on the video, as I already built it. It calls for a 4-50pf I believe.
  4. SparkyCal

    The Theremin Stretch

    Thank-you. I also need a 4-50pF variable capacitor. I'll look for one of those. Does you see one here:? details.php
  5. SparkyCal

    The Theremin Stretch

    Hard to find the J113s locally. I called another store and they said it has been replaced by the NTE469, but they don't have those either. Hmmmm If I can find something at that link above (Sayle Elecrtronics), that would be my best bet as I can simply go there and buy it
  6. SparkyCal

    The Theremin Stretch

    Here is the local store I use: https://secure.sayal.com/STORE2/shop.php
  7. SparkyCal

    The Theremin Stretch

    Thanks guys. Bertus- I can buy 20 J113's at Mouser for $8.23. Problem is, there is a $20 delivery charge tacked on. I need to find a cheaper option. I'll look around. I'll also see if the local electronics shop has them. In terms of the article, I looked at it, but plan to read it when I have...
  8. SparkyCal

    The Theremin Stretch

    Bertus asked: What voltage do you measure across R12 and R42? I would expect a voltage of about 1.5 Volts. I placed my negative and positive multimeter leads, one on each side of each resistor. In both cases, I got 0 volts. My variable power supply was supplying 6 volts to the circuit. So...
  9. SparkyCal

    The Theremin Stretch

    Bertus- sorry, I did not see your question about voltages, until now. I will measure and report back.
  10. SparkyCal

    The Theremin Stretch

    Are the oscillators a function of the JFETS? In other words, what is causing them not to work?
  11. SparkyCal

    The Theremin Stretch

    Here's where I am at. I read through all the posts on the original web pages and the JFETs I am using are said to be an updated version of one that is listed as working. So, it also holds that thre JFETs I am using will also work. I turn the circuit on, and plug it into a guitar amplifier, and...
  12. SparkyCal

    The Theremin Stretch

    Thanks. I think I have concluded that the breadboard is posing a problem in of-itself. In the original schematic and write up, the design calls for a V31 7BL06 Voltage regulator, but I don't see that being talked about in the video.
  13. SparkyCal

    The Theremin Stretch

    Thanks Harald and Bertus. I should have read the webpage that Bertus cited in detail. The designer of this circuit goes to great lengths to answer a slew of questions on those pages. From reading it, it looks like my parts need changing. The JFET i chose, for example has a parameter of 0 to -8...
  14. SparkyCal

    The Theremin Stretch

    I decided to try to build this and have it all breadboarded up. https://www.youtube.com/watch?time_continue=819&v=oRhO0MJIl58&feature=emb_logo . The schematic for it is at 6:50 of the video. It is a Theramin- which is a musical gadget of sorts. It makes zany noises when your hand moves toward...
  15. SparkyCal

    Part Replacement in Circuit

    I need to swap the pin mapping
  16. SparkyCal

    Part Replacement in Circuit

    Bought these. Leyal 10PCS MPF102 JFET AMP N-CH RF SS TO92 New
  17. SparkyCal

    Part Replacement in Circuit

    I researched it and learned that they are not interchangeable because one uses voltage and other, current. So I ordered soMe jfets. I hope I don’t already have some in that smattering of transistors that I posted.
  18. SparkyCal

    Part Replacement in Circuit

    Another question. In this video, he uses a particular transistor and references it’s drain and source. I am going to use BC537 transistors, but those commonly are referred to by collector, base and emitter. Why is the terminology different and do you think I can use the Bc537
  19. SparkyCal

    Why is it so hard to find ceramic capacitor kits that have a 3.3pF in it?

    Thanks guys. i was able to order an inexpensive assortment of capacitors (less that $20), that includes 3pF capacitors. so hopefully that will work. I also read what you wrote in an old Radio Shack booklet on electronics, in which it talks about tolerances allowing for substitutions to an extent.
  20. SparkyCal

    Part Replacement in Circuit

    What do you think should be the appropriate antenna length? As I explained to Bertus, I am leaning towards this circuit because it has a detailed video explaining the breadboarding, but also explaining the math. I thought it would be a good first attempt, with a view toward learning and then...
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