You've seen the envelope edges.
A transistor at its maximum current is not normally dropping the entire Vcc across it. There will be a load. A 2N2222 is rated as a switching transistor. At full saturation, the CE junction may have only 100 to 200mV dropped across it. The BE junction will, seemingly paradoxically, have 600 to 700mV dropped across it.
But times also must be taken into account. If I run 800mA at 0.2V, that's 1.6W. So clearly as an on-off switch, I must obey the most limiting limit.
However, if I'm using it to PWM, then as long as the switching frequency is fast, I can look at average power. So maybe 800mA at 40% duty cycle max.
Of course, you should never run parts at their limits. I like 2x. So for a transistor rated at 625mW, I'd avoid running it at more than about 300mW dissipation.
A class C amplifier, designed properly, is running at considerably less than 50% duty cycle. The transistor is on for only a short time during the positive incoming peak.
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Steven Greenfield AE7HD
Steven AE7HD