[Amps] W8ZR QSK Circuit

[Jim Garland]

Hi All,

            I designed a QSK amplifier keying circuit last year for a
homebrew amplifier, and QST is publishing a  writeup on the design in this
month's (June') QST. If you're interested, you can read an expanded veersion
of the article, along with numerous photos, on my website at
www.w8zr.net/QSK   (The "QSK" has to be upper case.)  

            The design uses vacuum relay keying, properly sequences the
relays and amplfier bias switching, and has an RF detect circuit that
prevents hot-switching. I've used the basic design in a couple of homebrew
amplifiers (photos of the one I finished last year are on the webpage) and
found it to work quite well. The components mount on a 3x5 in PCB and can be
retrofitted easily into commercial amplifiers that lack QSK.

            As with my other projects, Harbach Electronics is selling bare
PCBs for builders and also making the other components available.  They'll
be for sale at Dayton at their usual flea market spaces next to the big ramp
from Hara Arena.

Tnx and 73,

Jim W8ZR.