Note
QST, Dec 1972, P. 113.
QST, Mar 1973, p. 176. (good photo)
QST, Sep 1973, pp. 116–117. (specs and info on autotune)
QST, Jan 1974, p. 133.
QST, Oct 1974, p. 129. (SS-200A - good photo)
QST, Feb 1975, p. 109.
Three versions differ only in output power.
SS-15 – 15 watts PEP. $579.00
SS-100 – 100 watts PEP. $699.00
SS-200 – 200 watts PEP. $779.00
The SS-100 appears to have been dropped by Sep 1973, as it is not listed on Swan's ad in that issue of QST.