Prototyping RF

Discussion in 'Wireless & RF Design' started by PRS, Jan 15, 2010.

  1. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
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    Recent experience makes me think that breadboarding is not a good method for any rf circuit. I built an IF stage on a breadboard which I had designed and built in 1991. Back then it worked fine. This time it got a gain of only 6 volts per volt on the breadboard. I built it on etched copper clad and got a gain of 72! Which is what it should have been in the first place.

    This makes me think that for rf, anyway, a design on paper should be at least dead-bugged on copper clad board before making any conclusions about its merits or demerits. Breadboards are unreliable. Any thoughts?
     
  2. bertus

    Administrator

    Apr 5, 2008
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  3. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
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    Hey, thanks, Bertus, this is great! Making copper strips and pads that can be glued to a board leaves much to the imagination. Thanks!

    Here's a confession. When I first started prototyping, I was afraid of using etching techniques because of my own ignorance. So I created my own way of using copper clad boards. This involved cutting the copper with a knife into 'pads' then soldering the components to those pads. But both this and the etched board methods mean you already have to have designed the circuit right. The dead bug and Manhattan methods make for ease of redesign.

    And, along this line of thought, I recently read from the ARRL Handbook of a design that was first dead bugged and then turned into an etched board. It seems from this that ugly construction is best for rf prototyping.
     
  4. k7elp60

    Senior Member

    Nov 4, 2008
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    If you have want to make isolated pads on a piece copper clad board, I use this technique. I use a pen knife to cut the area I want to remove. Sometimes you can peel the area off once you have loosened part of the foil. On tough boards I heat the area to be removed with a soldering iron. This helps to peel of the area.
     
  5. radiohead

    Active Member

    May 28, 2009
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    won't clad pads glued to a copper plane act as a (low value) capacitor? (probably minimal as compared to a breadboard, though).
     
  6. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
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    This sounds pretty much like what I used to do, but without the heat. I'll experiment with heat. Thanks! :)
     
  7. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
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    What you say here makes, sense, radiohead. I should think the method is limited to rf below UHF, maybe even lower.
     
  8. Wendy

    Moderator

    Mar 24, 2008
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    If it is for power supply taps this can be a good thing, otherwise use point to point wiring. I've many a fine oscillator that was meant to be an amplifier.
     
  9. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
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    Thanks, Bill. LOL! (nt)
     
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