>
>At 2:12 PM -0500 2001/1/28, measures wrote:
>>...All one has to do to run class A is reduce the mic.
>>gain until anode current does not increase during modulation.
>
>
>True but incomplete, therefore confusing or misleading. If you want to get
>much power out of your amp you must reduce the negative grid bias (or
>perhaps with some tubes bias the grid slightly positive) to increase the
>quiescent anode current so that decreasing-current peaks are not clipped at
>all. You must limit dissipation to a safe level, of course. Most "linear"
>high-power amps are normally biased for Class AB operation, in which plate
>current cuts off during decreasing-current peaks.
>
... not with the Class AB1 amplifiers I constructed. In Class A,
anode-I never cuts off during during transmit. In AB1, anode-I cuts off
on each cycle as the grid is driven negative.
cheers, Chuck
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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