Ham Radio KITS - TOP PAGE - Washington Island BOOKS

May 21, 2014 - Bug Descratcher III kit

December 30, 2021: prices increased due to higher parts prices

October 2021: NEW enclosure parts kit

January 2019: kit now includes a solder masked, silk screened circuit board

The Bug Descratcher III kit is the third version of a circuit from the September 1992 issue of QST by WX7G, Dave Cuthbert. The Bug Descratcher III removes the "scratchiness" encountered with semi-automatic keys (bugs) due to contact bounce. It can also be used with straight keys. It features:

[Bug Descratcher III circuit board picture - 
click for larger version]
  • a debounced output to eliminate scratchy sounding keying
  • optional solid state relay (SSR) output to key nearly any rig (solid state, tube positive or tube negative keying voltage)
  • available as a board only kit
  • board size: 1.25 x 1.5 inches
  • operates from 9 to 13.8 volt battery or power supply
  • minimizes the input to output delay (previous versions had about 6 mS of delay)
  • price is $14.00, with SSR option $19, with enclosure $25, with enclosure & SSR $30 + shipping/handling
  • note that enclosure box is New Old Stock and may require cleaning and/or filing (sanding) before use
  • printed documents are NOT included, please print/view your own from the pdf files provided


  • For pricing, availability or any other questions, please send an email to me, Chuck Olson, WB9KZY at:



    with your question.

    Kit Documentation: download (Right click/save target as) and print the Bug Descratcher III kit manual , schematic diagram and hookup diagram
    enclosure manual
    all in Adobe Acrobat (.pdf) format.
    Here is a simple diagnostic test file in case of trouble.

    To purchase the Bug Descratcher III kit, print out a Kit order form to figure your order manually
    or try our: javascript order form to let your browser do the math!

    Ham Radio KITS - TOP PAGE - Washington Island BOOKS