ADS
© 2018 – DL4ZAO – Status: Preliminary v010
Seite 4
positive and the same as the supply voltage. The internal pullup resistor is 47kΩ. The “Remote OFF”
socket is isolated from the aluminum case.
„Remote OFF“ can be used to activate/deactivate the ADS for example by CAT Interfaces (e.g.
Stationmaster or similar)
Installation
The ADS is placed at the output of the receiver, transceiver, amplifier, or the antenna tuner. The device
may be placed close to the radio or outside the shack. Best protection is achieved when installed and
properly earthed before the feedline from the Antenna enters the building. Note that the ADS box is not
waterproof and need to get housed in a waterproof enclosure.
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Note: If a remote power supply over the coaxial cable is used to supply e.g. an active antenna or masthead
amplifiers, make sure that the ADS ist installed in the DC-free leg between Radio and Bias-Tee and not
between Antenna and Bias-Tee, else the remote supply voltage will be short circuited to ground.
Earth ground connection
To provide effective protection the ADS requires a direct conduction path with sufficient diameter to an
suitable earth ground point. Earth ground is tied either to the ground-stud of the ADS or via the flange
cover of the box mounted on a thick metal plate, which needs to wired to the ground earth system. An
effective station ground bonds the chassis of all equipment together with low impedance conductors
und ties into a good earth ground. Use a heavy conductor (copper, diameter 4mm, AWG #6) and
connect as short and as direct as possible.
The coaxial braid of the feedline, metal-water pipes or the protection earth of the domestic power
distribution are not adequate as earth ground connection for an antenna. Minimum requirement for an
earth ground point is one or more ground rods at least 1,5m (8 inch) long driven into the earth. The ground
rod should be solid copper or clad steel with 20mm (3/8 inch) in diameter. Earth Ground must be in
accordance to the national electrical codes and standards for antennas applicable in your country.
Circuit Diagram
