Brought to you by PCS Electronics, www.pcs-electronics.com
Appendix E – Wiring the Amplifier Control Board v4.0
Temperature sensors
Control board supports two temperature sensors. Amplifier temperature sensor and second sensor, which can be used either
for monitoring power supply temperature or monitoring some other parameters.
Amplifier temperature sensor is connected via the DIGIAMP (J2) interface and the actual sensor is located on the PCS LPF
5000 or 6000 filter boards. If you do not want to use the PCS LPF 5000 or 6000 you can also connect amplifier temperature
sensor to the DIGIAMP header manually. What you need is the 10K NTC resistor. Connect one end of this resistor to the
TEMP pin and the other end to ground. The pinout of the DIGIAMP header is printed on the main board of the
CONTROL BOARD V4.0. , use the TEMP pin.
Second temperature sensor can be connected to K (J9). It is the same 10K NTC resistor. You can set alarms for both of the
temperatures.
DIGIAMP interface
The digiamp interface greatly simplifies assembling an amplifier or transmitter. It easily connects to the PCS LPF 5000 or
6000 filters. Exact pinout is printed on the board. This 14-pin header connects the following lines:
- Amplifier current
- Amplifier supply voltage
- Measured Power and SWR lines
- ALC (used only for exciters)
- +5V and GND
Standby switch (J8) and LED (J10).
You can connect a switch with built-in LED diode here. Whenever you activate standby mode the supply voltage drops and
bias disable is activated. Makes it possible to quickly disable RF output.
BIAS DISABLE output
Most pallets have bias control inputs, this input is designed to shut off the pallet by altering the work point of the amplifier.
Bias disable function in control board helps shut off power either in standby mode or in alarm conditions (excesive SWR,
temperature, excesive drive). Two voltages are provided here, positive and negative. Depending on the pallet type used you
can use one or the other to disable the pallet under control.
With many pallets just pulling the bias disable input may be sufficient. To do this pull the bias disable low with the help of a
small NPN transistor or N-Fet. To shut pallets off completely you may need to pull bias disable slightly to the negative. You
can do this with the negative bias disable output.
To get the exact voltage needed feel free to use resistors, diodes/zener diodes or a simple NPN transistor.
ON-BOARD attenuator
Using a small attenuator at the input of an amplifier is recommended and levels up the matching between the exciter and the
amplifier. The on-board attenuator can take about 5-7W of power and also supplies a small sample of the signal to the
Appendix
E