[Elecraft] SSB Power

[Matt Osborn]

I'm a little confused about measured transmitted power when in SSB vs
CW.

As an example, I have an XV50 Transverter that is adjusted to produce
20 watts RF out when using the K2 'tune' control.  This output is
adjusted by reading 20 watts on an external power meter. The power
indicator LEDs are then adjusted to read 20 watts as well.

When using SSB, however, the RF out is much, much lower, maxing out at
7-8 watts PEP on the external power meter.  The  indicator LEDs,
however, indicate 10 - 20 watts of power.

I'm not certain I know how to understand what it is I'm measuring.  In
my mind, I think much the 20 watts RF out of a CW signal is actually
carrier and of not much  use.  When in SSB, I want to think that I can
still put out the 20 watts, only now all concentrated in one sideband.

Why does the power meter fail to show the 20 watts?