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D. PA 1000/S Power Amplifier
The PA 1000 uses eight power bipolar transistors arranged in four pairs of push-pull class “C”
amplifiers. The input power from the driver is matched with a wideband transformer, T11 and
T13. The driver inputs are then split into two signals with T12 and T14 and fed into four push-
pull transformers T7-T8. Each of these four transformers drives the bases of two power
transistors. The transistors are operated common source with feedback.
The collector signals are coupled by a push-pull hybrid combiner T15, T18, T20, T23. The
outputs of these combiners are once again added together two two -way hybrid combiners.
There are no adjustments on the PA 1000/S.
Typical Specifications
(PA1000)
Gain
18 dB
Input power
15 watts (typical)
Output power
1100 watts (min)
Input impedance
50 ohms
Output load impedance
50 ohms
Collector voltage *
42 VDC
Current draw *
46 ADC
* At 1000 watt system output into 50 ohm resistive load
E. Directional Coupler (schem dwg# FA0105RC)
The directional coupler has two detectors that monitor forward and reflected power. The
directional coupler produces voltages, which are proportional to the square of both forward and
reflected power. The signals from the two detectors are produced from inductive (current) and
capacitive (voltage) taps off the output line. The forward power and reflected power signals
are fed into the OCB where they are linearized. They are then used to drive the front panel
meters and for remote output monitoring. The reflected power signal is only present when the
generator is driving a load that is not purely resistive, or not 50 ohms. This signal is also used
to drive the VSWR shutdown circuitry.
F. CPS Meter Board (schem dwg # FA0603RE)
The CPS meter board is the major connection and routing point in the CPS generators. It is
also the location for the +/- 15vdc and +12vdc power supplies, interlock transformer, over
voltage (OV) and over current (OC) foldback circuits, enable circuit and over temp circuit.
VIII. Adjustments and Calibration
The only adjustments required on the CPS-1001/S are made to the monitoring and transistor
protection circuitry. All of these adjustments have been performed at the factory and generally
will never have to be readjusted.
CAUTION:
Unauthorized resetting of any adjustments will
void the warranty
.
A. Over Voltage / Over Current Adjustment
The OV OC potentiometer adjustments are located on the CPS meter board (R22 and R21).
These adjustments should be altered only when the generator is operating into a 50 ohm real
load. The procedure for adjustment is as follows:
Summary of Contents for CPS-1001/S/13.56MHZ
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