__________________________________________________________________
RF Technology PA70 Page 4
2 CIRCUIT DESCRIPTION
regulate the power. The output power can be set to any level between 25 and
70 watts.
RF Level Detector
The RF Detector threshold for the RFO LED on the amplifier front panel is set
by RV1. This is normally set at half the rated output power.
Warning
Ensure that the output power setting complies with the equipment’s license
requirements. Failure to do so may result in penalties being imposed by the
licensing authority.
PA70 Amplifier I/O Connections
25 Pin Connector
Function Signal
Pins
Specification
DC Power +12 Vdc
0 Vdc
1,2,14,15
12,13,24,25
+11.4 to 16 Vdc
ALC Output
8
Approx 7 Vdc decreasing with
increasing power or temperature
RF Input
BNC Connector
25 Watts Max.
RF Output
N Connector
70 Watts Max.
2.
Circuit Description
The following descriptions should be read as an aid to understanding the block
and schematic diagrams at the rear of this manual.
2.1
Amplifier
The RF power amplification is provided by a single transistor, Q4. The
transistor provides at least 10dB gain in the 66-88 MHz frequency range.
The input and output impedance of the transistor is matched to 50 O by
networks which use printed micro-strips and lumped elements. Variable
