Regarding “Little Joe”

Wes Hayward, September 9, 2015

raw board
An  article by Doug DeMaw, W1FB, (SK) in the September 1981 issue of QST featured a simple CW transmitter.   The article was titled “Experimenting for the Beginner” and talked about some of the things that one might do if he or she had never built a circuit of any kind.    The transmitter was a variation of one that Doug and I had included in our 1977 book, Solid State Design for the Radio Amateur.    We named the little rig from SSD (p26) a “Universal QRP Transmitter.”  Nowhere in the QST article text, the related figure captions, or even the references does the term “Little Joe” appear.   Yet this is the popular name that has been attached to that design.    I finally discovered the reason.   The circuit board photo (p45 of the QST, above figure) reveals the “Little Joe” name, etched into the foil.   

This design is very old and suffers from numerous problems.    Yet I continue to receive questions about it.   Folks continue to build it.    Pre-etched circuit boards are rumored to still be available from a bargain basement source that does not bother to include any road maps (layout diagrams showing parts placement) with any of the boards that they sell.  Many current builders are using the on-line copy of the QST article that is available (members only) at the ARRL web site, but the figure resolution from that copy is poor.   I got permission from the League to put slightly higher resolution diagrams on my website.   

The “road map” and a board photo are shown below.   These were scanned from the original paper QST.

road map
board photo

I do NOT recommend this design which is, by now, well over a third of a century old.    Rather, a design that meets FCC specifications and has numerous operating features was presented in a recent QST.    See “An Updated Universal QRP Transmitter,” QST, April 2006, pp28-32.    A related note appeared in Technical Correspondence, QST, July 2006, pp65-66.    Errata for the article appear on this web page at http://w7zoi.net/mark2.html which includes comments about up to date, available, cheap transistor types.    The updated design appeared in some recent issues of the ARRL Handbook.    The new design does not have a printed board layout.