This subject keeps getting repeated over and over because those who don't know, will not or cannot understand the reasons for amplifier operation in class A, B and C.
Those who know are not listened to by those who do not know so the foolishness keeps rolling on and on.
FOR SSB;
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Class C operation has the bias set to A POINT BELOW the 'CUT OFF' of Plate/Collector current.
When drive is applied the device is driven up out of cutoff by varying voice rates.
THIS IS WHERE MOST OF THE DISTORTION and SPLTTER PRODUCTS COMES FROM.
Part of the drive never get through the amplifier, especially the low amplitude part of the driving signal. The parts the do break the device in to conduction is so abrupt that the distortion and splatter is produced.
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.CLASS B operation is a little better but can still produce some of the same undesirable products in a single 'ended amplifier' this means (not push-pull).
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Class A operation has the plate/collector current flowing at about 20%+/- of total current. This makes the amplifier about as Linear in operation as the devices will give and generate the least undesireable products.
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. WHAT does Linear mean? A near faithfull reproduction of the driving signal.
Class C cannot do that being biased below device cutoff and losing part of the drive signal plus causing products that are not normally in the original driving signal.
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Some other supporting comments are you would never run an audio amplifier class C and put up with the distortion on your favorate music so why do it with an RF amplifier that would not be running in true Linear mode?
The other side of this is most of you do not know when enough drive is enough. How would you know unless you understood the principles behind bias levels vs the specific devices in the amplifier?
Take a look at all the amplifiers that have been roasted because the user did not know better..
Lastly, it's aways a joke when you tell an op he is splattering and a mile wide and he comes back with "it must be your receiver" when 'he' is generating the trash 'he' cannot hear. Under what basis would he know your receiver has a problem; he dosn't!
Hope this helps to settle some of the on going unwillingness to accept the technical facts.
Even if you don't understand them, just believe it.
Good luck.
