ADS
© 2018 – DL4ZAO – Status: Preliminary v010
Seite 3
FUNCTIONAL DESCRIPTION AND OPERATING GUIDELINES
With Power turned OFF the ADS is in protection mode, the antenna’s coax signal and shield are shorted
together and the antenna is connected to ground. The antenna line is completely disconnected from the
radio equipment. With Power turned ON, the “TO ANTENNA” connector is connected to the “TO RADIO”
jack and ready for operation.
Power for the ADS antenna switch comes either from the transceiver’s external accessory output or
directly from a power supply. In case the ADS is powered via the transceiver accessory output, the ADS
disconnects, when the transceiver is switched OFF. When the transceiver is powered ON, the ADS re-
connects the antenna’s coax for normal operating.
The ADS needs a supply voltage in the range between 10V und 18V. A green LED indicates when the ADS
is activated and the antenna is connected to the radio.
The “Remote OFF” Input is an additional feature of the ADS that allows to disconnect the antenna
remotely despite power is applied. With a manual switch or an open collector connected to the “Remote
OFF” RCA/Cinch jack an “active low” level deactivates the ADS and the antenna becomes disconnected
from the radio.
Operating conditions:
ON – Connected
Antenna is connected to the radio equipment, green LED is illuminated.
OFF – Protection
ADS is in protection mode. Coaxial Line to Radio equipment is disconnected.
Feedline from Antenna is connected to the grounded metal case. Green LED
display ist off.
Learn more about the various operating conditions in Chapter „Activation Methods“.
Transmit operation: Under specific conditions with highly mismatched antennas and high VSWR,
standing wave voltage maxima could be high enough to trigger the Gas-Discharge-Tube. This may occur
only when using high power and non-resonant antennas with extreme VSWR.
Power Supply
The Relays in the ADS are operated with a smoothed or stabilized DC supply voltage in the range of 10 to
18V. The relays need a current of 60 mA for safe switching. At 12V, the typical operating current is 70
mA, at 13.8 V the current is 85 mA. The operating power can be taken out of a DC-Power Supply or from
the external accessories output of the radio. When the radio is turned ON, 12 volts appears on this
output and the actuator is switched ON. Most radios use an RCA/Cinch plug. Wire the red wire of the
twin core flat litz to plus and the black wire to minus. A Plus and Minus sign is printed on the pcb at the
screw-terminal inside the ADS box.
“REMOTE OFF“ Input
The “Remote OFF” Input is intended to remotely disconnect the antenna despite power is applied to the
ADS. With zero voltage contacts or an open collector Transistor switch connected to the “Remote OFF”
RCA/Cinch jack, a “low” level deactivates the ADS and the antenna becomes disconnected from the
radio. The “Remote Off” Input ist a RCA/Cinch Socket internally wired to a 2-pole Pin Header (K4) on the
PCB. If you shortcut the inner conductor of the RCA socket with the outer conductor, a MOSFET brakes
the supply of the relays and the ADS disconnects. The Voltage at the inner conductor of the jack is
