Communication Concepts AN762 Construction Hints - Manual (Page 7)

4. With a DC current meter connected in the power lead and without any RF applied
to the amplifier input, turn on the DC power supply and adjust the potentiometer
to the recommended idling current noted in the Application Note. The minimum
recommended collector idling current is 100mA per device or 200mA total.
5. Slowly bring up the input RF power until the RF output power equals the
maximum power recommended in the Application Note.
6. The output of the amplifier will contain harmonics of the input signal. Low pass
filters must be used on the output of the amplifier to reduce the harmonics to
meet FCC regulations for spectral purity. The filters shown in Figure 6 will
provide more than sufficient harmonic attenuation with less than 1 dB insertion
loss at the operating frequency.
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