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active antennas may be used with the External receiver if it conforms with
the following requirements. Gain: Antenna should
provide between 10 dB to 30 dB net gain between the antenna feed point and
the connection to the Star Sync receiver. Consider all amplifier gains;.
filter losses, cable losses, etc. when calculating the gain.
Connection: MCX male connection. An antenna with a
different type of connector can also be used.
Antennas with BNC, N, SMA connectors
Other types of antennas can also be used if:
- a suitable adapter is used to connect to the MCX jack
- the active electrical nature of the connection is
observed
Other antennas terminated in a BNC, N or SMA connector may
also be used if a MCX Adapter is used
(available from Beagle Software). Place the MCX adapter
between the connector on the end of the antenna cable and the connector
on the Star Sync receiver.
The total noise on the external antenna must be <= 7dB
with a gain between 10 dB and 40 dB. Properly bias the antenna from receiver
source or an external source. The Star Sync receiver supplies 3.0 VDC to the
center conductor of the MCX female relative to the connector shell ground.
The source resistance of the DC supply to the center of the conductor is
approximately 10 ohms, which is included as a current limiting resistance.
This resistance allows the receiver to survive momentary shorting of the
antenna port. There is no provision to protect against a continuously
shorted antenna port.
If bias voltage is supplied from an external source than
the supply must be 4.0 to 8.0 VDC bias through the series combination of an
on-board ~10 ohm current limiting resistance and a Schottky diode.
In either case the antenna must not draw more than 60mA.
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