The driver stages 1+2 get their input from the 13560 kHz oscillator.
The output voltage of the oscillator is approx. 400 mV peak-to-peak
(280 mV eff) if left open. The source resistance of the oscillator is
approx. 300 Ohms. The signal at the input of the driver stage 1 is 
approx. 210 mV peak-to-peak (150 mV eff) if connected. At the output
of the driver stage 1 you may measure approx. 2.4 Volts peak to peak
if left open. With a load resistor of more than 100 Ohms, the source
resistance of the driver stages 1+2 at its output is about 15 Ohms.
With a load resistor of 150 Ohm at the output you get approx. 2.2 Volts
peak-to-peak (1.55 V eff). Maximum power output of the driver stages
1+2 is less than 44 Milliwatts/100 Ohm or 16 Milliwatts/150 Ohm.
You may not use a load resistor below approx. 100...150 Ohms because
distortion appears and increasing harmonics are produced. Without a
load resistor, the second harmonic (27120 kHz) is about 60 dB weaker
than the fundamental (13560 kHz), according to approximation using
my Grundig satellite 3400 prof.