MPSA18 transistors work in every orientation, why?

[PRR]

The common base current gain (or α) of a point-contact transistor is around 2 to 3, whereas α of bipolar junction transistor (BJT) cannot exceed 1 and the common emitter current gain (or β) of a point-contact transistor cannot exceed 1, whereas β of a BJT is typically between 20 and 200.

[Rob Strand]

That was before your time, I see.

Nothing to do with "reverse".

FWIW,  I come from the Beta = emitter current gain, Alpha = common  base current gain planet.   IIRC the forward, reverse,  beta, alpha stuff appears all together in texts describing the Ebers-Moll Model.

[patrick398]

[mac]

mac