5 CIRCUIT DESCRIPTION AND SCHEMATIC DIAGRAMS RE21005.8 POWER UNIT (MODULE 8) PART NO. 625638REGULATORSThe power module receives three voltages +9V, +18V, and -18V from the power supply placed in thetransmitter T2130. Seven regulators are converting these voltages to the different working voltages usedin the RE2100.U01 and U02 deliver +15V and -15V only to the exciter module. If the transmitter has not been used fortwo minutes the microprocessor shuts down the regulators U01 and U02. This takes place via the shiftregister U07-4 in the exciter module and the transistors Q01 and Q02. This is done to save powerconsumption in the stand-by position. Regulator U06 is factory adjusted to deliver 5.25V output voltage.RF AMPLIFIER AND FILTERThe transistors Q03, Q04, and Q05 form an RF amplifier to boost the exciter output to a level requiredby the transmitter. The output level can be adjusted by means of R30. To reduce harmonics producedin the exciter module a low pass filter is placed between Q03 and Q04. The RF output is a ready to sendsignal.PAGE 5-419324
