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  1. CDRIVE

    Is it normal for an opamp to "rectify" a signal?

    He said he built a noise gen that I thought was not shown on the print. I thought the transistor was a mis-wired buffer amp... Duh!! It's been a while but I remember Tunnel Diodes being a favorite for noise gens. Chris
  2. CDRIVE

    idea for creating Touch sensitive wire strip like variable resistor

    Steve, brain fart on this end! Yes, you're absolutely correct and so was Toy. My last post I was still stuck on SWR, which is better described and stated as Reflected Power. It has little to do with Toy's theory. Yes, that's how antennas work! ;) Chris
  3. CDRIVE

    idea for creating Touch sensitive wire strip like variable resistor

    Yes, but this does not hold true for transmission lines properly terminated in it's characteristic impedance at both ends. In this case the only differences from input to output should be dielectric and radiation loss. Usually,the more expensive the transmission line the less one should see in...
  4. CDRIVE

    LC meter accuracy

    Yeah, like that! By the way, that was dirty pool! I spent over 20 min searching it and the instument that uses it, Then I spent another 20 or so min reading through this .pdf...
  5. CDRIVE

    USB Input switch

    Hopefully I'll find time to draw it for you tomorrow. Chris
  6. CDRIVE

    Is it normal for an opamp to "rectify" a signal?

    Steve, I really am loosing short term memory. It took me nearly 3 minutes to understand that. Yes, the bar napkin! :D Chris Edit: Steve, where is the noise gen being injected? :confused:
  7. CDRIVE

    idea for creating Touch sensitive wire strip like variable resistor

    Are you referring to SWR? Chris
  8. CDRIVE

    USB Input switch

    Does this help? Chris
  9. CDRIVE

    USB Input switch

    We doubled on that last exchange. Dick Cappel is well respected. He's a well known electronics/computer author. His design should work fine. Pigtails: I don't like them much either but it does prevent making a mistake by plugging an input to a PC and the output into another PC. This...
  10. CDRIVE

    DIY 5X low wattage amplifier for Biotech research

    Thank you for the explanation. I was concerned that something like this could be used for malicious RF transmission. Chris
  11. CDRIVE

    USB Input switch

    I missed this schematic and it's a different ball of wax. If we're talking switching between two USB devices then what I've said in my second post (3PDT) would be valid. The device in your link switches your single USB device between two PC's. Is this what you want? If so my second post would...
  12. CDRIVE

    USB Input switch

    I would make all three USB ports Female. This way you can use standard USB Male to Male cables to plug into all three ports. By the way, I've reconsidered hard wiring the +5V power line. The reason being is simply power waste. If GND and Power are always connected you would be powering the...
  13. CDRIVE

    USB Input switch

    Woops! I forgot to post this link. http://pinouts.ru/Slots/USB_pinout.shtml Chris
  14. CDRIVE

    USB Input switch

    Nerdtastic, welcome to EP. Yes, Instructables is not my favorite tech site. Two of the pins on a USB port are GND (-) and Power (+5V). I don't see that you need to switch these lines. At most you will only have to switch Power (+5V), Data(+) and Data(-). This will require only a 3PDT switch. On...
  15. CDRIVE

    DIY 5X low wattage amplifier for Biotech research

    Hi gandalf, are you going to answer my question? Chris
  16. CDRIVE

    Is it normal for an opamp to "rectify" a signal?

    Besides the other odd stuff on the schematic check out the NPN connections.???? :confused: BTW., Agreed that the 741 is neither low noise nor modern but we need a low noise amp for a white noise amplifier ..why? :rolleyes: Chris Edit: I would think that the prime requirement would...
  17. CDRIVE

    Help with Tiny Monitor Cube Thingy

    I was fully expecting CC to reply because he takes on contracts but it hit be that I haven't seen a post from him in quite some time. I certainly hope everthing is OK. Chris
  18. CDRIVE

    DIY 5X low wattage amplifier for Biotech research

    Why do you need power output levels this high? Chris
  19. CDRIVE

    idea for creating Touch sensitive wire strip like variable resistor

    If you're looking for a simple finger bridging circuit that demonstrates where along a resistive divider your finger has bridged the circuit you can put this together. I show a 9V battery and an Ammeter but a basic Ohmmeter will work just as well. Placing your finger across any of the 4 touch...
  20. CDRIVE

    LC meter accuracy

    Steve, thanks for taking the time to run those test. Believe it or not I still don't own a digital C or L meter. I think I once purchased a small kit intended to be used with a DMM or AMM but I was sidetracked by something (it's always something) so it's buried somewhere in my storage bay. I...
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