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  1. CDRIVE

    Does Your Wiring-Soldering Look Like This?

    While searching designs of LC oscillators for another thread here I stumbled upon this example of point to point wiring. http://www.classeradio.com/vfo.htm I would highly recommend that anyone that is wiring at this level of expertise (or lack of it) spend a whole lot time practicing. I...
  2. CDRIVE

    LC tank circuit for measuring inductance with LM319

    The Colpitts Osc. lends itself well to Crystal Osc. design as stated in the link I posted. That doesn't translate to a being the best design for VFO or broadband oscillator design. Are you under the impression that your going to be able to measure uH to mH or even Henries without providing a...
  3. CDRIVE

    Arduino used as a PIC programmer

    Yeah, that works for me. 'Vague' is never a good spec in any field of study except politics, where vague & blatant BS is prized above all things. :p Chris
  4. CDRIVE

    LC tank circuit for measuring inductance with LM319

    Ah! OK mates I understand now. What is the input Z of your scope? If it's an Arduino/PC based scope I would think that negative signals to the input would be verboten. I would also guess (I have no experience with Arduinos) that it would employ protection diodes to prevent this. If that's the...
  5. CDRIVE

    LC tank circuit for measuring inductance with LM319

    Actually just the opposite. You're Spice scope most probably has an input Z = infinity. Spice doesn't like caps with no DC return to GND. It makes it difficult to resolve the hanging node. A 1Meg will help spice resolve the node even better. The smaller the coupling cap is the higher R can be...
  6. CDRIVE

    LC tank circuit for measuring inductance with LM319

    Hi Harold, I forgot to reply to this. Here's another and more common version of a colpitts... http://en.wikipedia.org/wiki/Colpitts_oscillator If you juggle the elements of snake0's circuit you will see that it's a common base version; similar to the wiki link. ;) Chris
  7. CDRIVE

    LC tank circuit for measuring inductance with LM319

    Place a 10 Meg resistor across the scope input. Chris
  8. CDRIVE

    LC tank circuit for measuring inductance with LM319

    I have to jump in the shower. I'll ponder that while in there. No guarantee that I'll agree when I'm drying off though. :) Chris
  9. CDRIVE

    Arduino used as a PIC programmer

    I get that but my issue is with the "R value" statement. "Anything over 200R will be fine" implies near infinity is OK. Chris
  10. CDRIVE

    C vs C++ with uControllers

    November!! Actually that's not surprising for me. My wife says I don't notice a damn thing unless it pisses me off. :D That aside I'm enjoying the discussion. ;) Chris
  11. CDRIVE

    LC tank circuit for measuring inductance with LM319

    Steve, I don't understand this. I would think that shorted windings would reduce the inductance and increase Q. My logic is ... Shorted windings equate to less coil resistance. The lower the coil resistance the higher the Q. Chris
  12. CDRIVE

    Arduino used as a PIC programmer

    The notes included with that schematic states this: Huh??o_O Chris
  13. CDRIVE

    C vs C++ with uControllers

    I think I love this discussion. It's more like cerebral combat though. Since I've not advanced passed the level of Basic languages I have only comprehended the information commensurate with a Chimpanzee! :confused: Kris, congratulations on your elevation to Moderator. I'm surprised that the...
  14. CDRIVE

    help in speed changing

    Ha, that made me laugh but you're right! I did. Chris
  15. CDRIVE

    help in speed changing

    I think your misinterpreting my post or perhaps you don't get my point. Come to think of it that may be the same thing. :p Chris
  16. CDRIVE

    help in speed changing

    Kris, wouldn't average current or even power be a better expression of what PWM does? ..... Or am I being picky?:) Chris
  17. CDRIVE

    Help with speed control

    Before you put this on the back burner I want to clarify a few thing said in this thread. First on the list is the term "Pot", which is an abbreviation of Potentiometer. A Pot is a three terminal device and all three terminals must be connected correctly to satisfy the definition. A Pot can be...
  18. CDRIVE

    Building a Dummy Load Box

    Ha, didn't catch this in his first post. I guess wireline resistance means total measured DC resistance of a shorted loop. Chris
  19. CDRIVE

    Help with speed control

    I clicked the link and read the specs, if they can be called that. Anyway, would it have killed them to list the current draw @ 1.5V? Developing a 1.5V PWM circuit intrigued me so I played with a few ideas and spiced them. Even if I or another member supplies a schematic that will work it may...
  20. CDRIVE

    Help with speed control

    Uh, you may want to refine these statements. o_O Chris
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