ATLAS 4500 Multimode Station Technical Manual
A-9
135-175 MHz Power Amplifier
Appendix A - VHF Circuit Descriptions
IC4 is configured as a boost DC-DC converter and pr25 V DC output.
IC3 reg5.2 V supply down to +5 VDC.
IC48 reg5 V supply down to +3.3 VDC.
A.3 135-175 MHz Power Amplifier
This section contains information on the following Power Amplifier components:
• Attenuator
• Driver Module
• Output Power Amp
• Power Coupler
• Power Detector
• Harmonic Filter
• PTT Power Control
• Auxiliary Circuits
A.3.1 General Description
The PA contains the following components
• Variable attenuator
• Driver module
• Main power amp
• Cooling system and heat sensor
• Coupler for DPD system.
• Power detector
• Low pass filter
• PTT switch
• Serial flash memory and regulator