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Heathkit SB220 Problems

Discussion in 'Amateur Radio Amplifiers' started by K9NRA, Jun 11, 2015.

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  1. AF6LJ

    AF6LJ Ham Member QRZ Page

    Yes that will work fine, just keep the connections short.
  2. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I'd use the .017" x 0.5" straps. And as indicated above, use one strap directly to ground at each grid pin.

    The parasitic suppressors you pictured above aren't anything remotely close to "stock." I'd go back to the stock design, it worked fine and the carbon comp resistors would drift high in value over time and with heat but that usually didn't matter much.
  3. AF6LJ

    AF6LJ Ham Member QRZ Page

    Agreed on all counts.
  4. W1BR

    W1BR Premium Subscriber QRZ Page

    Only problem is that is hard to find exact carbon comp resistors these days, unless they are very old stock. Modern carbon resistors may look the same, but they are often a bit more inductive, which is critical for VHF parasitic suppressor applications.

  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Ohmite OY series directly replace the carbon comps and are actually better (more stable, don't drift so much).
  6. KM5FL

    KM5FL Ham Member QRZ Page

    Can those "OY" resistors be mounted inside the suppressor coil, or should they be mounted outside the coil??

  7. AF6LJ

    AF6LJ Ham Member QRZ Page

    There shouldn't be any problem mounting them inside provided you make the coil the same dimensions as the stock coil.
  8. WA6MHZ

    WA6MHZ Premium Subscriber QRZ Page

    Wish I had an SB-220 to have problems with!!! I might crack a few pileups I cant now!
  9. K9STH

    K9STH Ham Member QRZ Page


    Sell a few of your duplicate, triplicate, quadruplicate, etc., hoard and you will have plenty of money to purchase an SB-220!

    Or, acquire a couple of the inexpensive Russian triodes and build an amplifier.

    Either way, you can acquire an at, or closely approaching, maximum legal power at very little out-of-pocket expense. I do realize that getting rid of even a single item from your "stash" would produce withdrawl symptoms worse than denying heroin from a drug addict. Unfortunately, "cold turkey" is the only way to really take care of such an extensive habit and to achieve certain goals in life.

    Glen, K9STH
  10. W1QJ

    W1QJ Ham Member QRZ Page

    I have them, make them and sell them. Clones of originals.

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