Around 1980 I worked for Bob Bollinger, the engineer from Hayden that designed their Sidewinder amps. He had left Hayden and opened a new company, Soltronics Inc in Anaheim Ca. I was the tech there.
The amp in your picture certainly has the name Hayden and Sidewinder on it but it has Palomar TX100 circuit boards and chassis. That is the only one I have seen like it. Who knows how that came about. The faceplate certainly looks to be professionally done.
Yes Hayden did use 568BLY transistors.
At Soltronics I rebuilt quite a few Sidewinder 350s and installed 100 watt transistors (MRF421). I was never fond of the board design/layout but they worked fairly well.
Bob/Soltronics made a few 4 transistor amps but not many, I still have a couple of them. I never liked the 568BLY transistors, very poor performers, prone to self oscillation and self destruction. IIRC they were spec'd as 80 watt devices. I always preferred Motorola and Toshiba and now HG. The Soltronics TX200CW did use those or CTC transistors but I changed them in mine. I'll post a couple pics since most people have never heard of this amp because of their limited production.
This Soltronics amp has been sitting on a shelf collecting dust in my warehouse for 40 years. It was used on an FM CB repeater (Pirate Radio Group) in So Cal for a while and battery acid somehow leaked on it. So it looks pretty crusty. The filter board in it is from a Palomar. I installed that on the input to clean the amp up for the repeater. It had a commercially made Low Pass filter on the output externally.
If you can see the circuit board under all the crud, it is very similar to the Sidewinder 350, just no driver transistor. These amps, TX200CW, had an oscillator and a crystal socket making them a "transmitter" which was the common ploy for amp builders at the time to avoid FCC raids.
After Soltronics closed down I built TX mobile amplifiers for a few years, until around 1986/87, TX200, 250, 300, 350, 400, 500, 600 and 800. Also some Silver Streak clones we called the DX180 and DX200, DX225.
I worked for Sundance Electronics as a tech prior to working for Bob at Soltronics. Sundance Electronics in Garden Grove Ca was the home of the Silver Streak amplifiers. Brian Godley did the engineering and board layout for the Silver Streak amps.
Sundance closed because of an FCC raid. Turned in by a dealer who refused to pay his bill...
Soltronics closed because of an Anaheim PD SWAT team raid, we were building pay TV - ON and Select TV decoders at night after the amp repair shop closed. The criminal charges were dropped later but the lawyers/legal problems put Bob (and his business partner Mark) out of business and me out of a great job with 2 great bosses.
