Difference between high level modulation and low level modulation.

HIGH LEVEL MODULATION:
parameter:
1. power level: modulation takes place at high modulation level.
2. types of amplifier: highly efficient class c amplifiers are used.
3. efficiency: very high.
4.devices used: vacuum tubes or transistor for medium power applications.
5. design of AF power amplifier: complex due to very high power involved.
6.applications: high power broadcast transmitters.

LOW LEVEL MODULATION:
parameter:
1. power level: modulation takes place at low power level.
2. types of amplifier: linear amplifiers are used after modulation
3. efficiency: lower than high level modulators.
4. devices used: transistors, JFET,OP-AMPs.
5. design of AF amplifier: easy as it is to be done at low power.
6.applications: sometimes used in tv transmitters(IF modulation).