here is a quote from someone who knows alot more about this than i do:
"I remember seeing that "minimum crossover distortion" nonsense back in the day. Pretty meaningless. One way is to listen to the radio on a second receiver. Turn the mike gain down so you only get a half a Watt or so on voice peaks. Now turn the bias pot to zero (in a radio that has one). Slowly advance it while modulating the radio at low power on SSB. It will sound horribly raspy until the trimpot reaches the threshold where you are getting some idle current. The audio quality will improve dramatically at this threshold point. Setting it just above that spot is not a bad way to do it. You run the risk of setting it too high and cooking a final. Less risky to set the driver bias this way, but still not as good as putting a current meter in line with the collector circuit.
Turning the mike gain down for a Watt or less peak output will let you 'hear' that crossover distortion, and also the bias-trimpot setting where it begins to go away. But only if you have a variable control to set it in the first place."
maybe give his method a shot if you aren't getting anywhere.
LC
