Editing Peak envelope power (section)

==PEP level control==
Most modern amateur transceivers sample PEP to adjust power, using an ALC (automatic level control) system. Time delay in the ALC system and finite time of RF signals passing through multiple stages, in particular narrow filters, often gives rise to unusual envelope distortion. This distortion commonly appears as envelope power overshoot on leading edges, and sometimes causes negative carrier shift on AM. Some more poorly designed transceivers have a short term envelope power overshoot several times the steady-state PEP setting. This envelope overshoot further complicates definitions of PEP and average power.                     

PEP was often used in non-[[Broadcasting|broadcast]] AM applications because it most accurately described the potential of mobile transmitters to interfere with each other.  Its use is now somewhat [[deprecated]], with the ''average'' [[transmitter power output]] (or sometimes ''average'' [[effective radiated power]]) now typically being preferred.