Registered in England No. 08405712
VAT Registration No. GB163 04 0349
Siretta Ltd
Basingstoke Road
Spencers Wood
Reading
Berkshire RG7 1PW
sales
email
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+44(0)118 976 9000
www.siretta.com
41
QUARTZ-ONYX
Hardware Manual
The maximum allowed load current of the antenna allowed is 25 mA. With 25 mA load,
the supply voltage to the active antenna is 3.0 V and with no load 3.3 V. The output
voltage scales linearly with the load.
The GPS antenna should be placed where it has the best possible view of the sky. The
greater the view of the sky, the greater the number of satellites that the GPS receiver
will be able to see. More satellites in view means faster time faster time to first fix and
greater position accuracy.
With unobstructed line of sight to the sky in all directions, 8-10 satellites should be
visible. If placed against a building such that half of the visibility to the sky is obstructed,
then 4-5 satellites would typically be seen. Four satellites are required to establish
the position. Having established the position, it is possible to maintain the position
measurement with only 3 satellites.
Figure 24.
GPS Antenna Connectors (GPS Version)
