Re: QSX 10W HF Linear PA kit
am not sure which three transistor W7ZOI amp you are referring to, but suggest you look at
which uses a Hayward hyb Cascode amp and subs amplifier to drive a PA - all the early bits are class A. Enhancements include using two J310 Fets in parallel (Q90 should be a current hog compared to a J310 JFET, and changing out the final transistor. All done without magic MMIC . 250 mW Linear should be possible ie about 3dB greater than as found.
That 250 mW will give you 8 W out from 3.5 to 30 Mhz if used with topology in Kee's (Talen) 16 W linear amp.