On 23-May-10 4:06 PM, Joe Subich, W4TV wrote:
> > The beauty of 1 dB compression power is that unlike two tone testing,
> > absolute accuracy is not required to achieve proper operation of the
> > amp.
> Sure, if you end up reducing the drive by 3 dB because the user
> can't tell the difference between 1 dB compression in the amplifier
> and 1 dB of foldback in the drive due increased input SWR.
What are you talking about? How does measured power applied to the input
jack have anything at all to do with what's going on in the exciter? I
don't understand your point. 100 Watt carrier doesn't care if the
exciter is in compression or folded back or standing on it's head. 100
watt carrier is 100 watt carrier period.
> > You DO NOT need to know what the actual power output is, you
> > only need to know at what point you should be adjusting the
> > drive to when running a linear mode.
> You do need to know both the drive and output accurately. That
> is the only possible way to accurately determine the gain of the
> amplifier and thus determine when the gain has dropped by 1 dB.
NO NO NO NO. You only need to know the RATIO between the output and
input power. That's what a dB is... A RATIO .. That's what GAIN is....
A RATIO.... Even an uncalibrated watt meter will give you that
information as long as it is linear. Why do want to make this harder
than it really is?
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