Complementary amplifier Differential Measurements for duty cycle

Using an O-scope to measure Differential Measurements on Two channels for Complementary amplifiers.

O-scope channel#1 is on the Positive cycle of the complementary amplifiers output
O-scope Channel#2 is on the Negative cycle of the complementary amplifier output

The input signal is not a sinewave, it's a square waveform

When measuring the On time and off time of the complementary pairs amplifiers output using square waveform, the Oscope is Ch1 - Ch2 differential measurement.

This will give the Duty Cycle?

 

The Transistors used for the amplifier is 2N6295 and 2N6297

On the datasheets there is a parallel Diode

what is this diode for? the diode is reversed compared to the Emitter to base diode in the transistor , why is that

To balance the swing?
To Clamp the voltage and limit the current?
To Stabilize the output?
To Protect from reverse polarity or a short circuit?

 

Here is the power transistors diode schematic