Beginning with the schematic - I used EI9GQ's specification. The transformers gave me pause and I had to really "noodle" over their construction. In addition to figuring out the windings and interconnections, if you read the article EI9GQ recommends torroids and shielded wired that do not seem to be available anymore. For transformer T3 he specifies HEM3011 torroids, I substituted two FT50-43s glued together for each side of the transformer, I also just used #26 AWG for the bifilar turns rather than the shielded audio cable that he recommended.
And here is a demo of the recreated smoke test. Much to my delight, after correcting the orientation of the voltage regulator that amp worked straight away. With the transistors biased at 500mA each I measured just over 13dB flat across the entire HF amateur radio spectrum,
The next step will be to replace the IRF-510 stage of my Furlough with this amp and see how it works on the air. As I mention at the end of the video I suspect I'll need to add another driver stage to get enough drive for the full 16 watts.
After close to two years of working on projects I'm starting to realize that Pete's adage - "if you know stuff, you can do stuff!" is really true. It has been a steep knowledge climb for me - but I'm starting to feel it.
73 from Great Falls