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GeminiG3 – 700MHz User Manual
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5.3 Additional test details
5.3.1 GPS
Test
About three minutes after ignition is turned-on, the PWR LED on the GeminiG3 unit front panel should
flash in amber color at the rate of one pulse per second. This indicates that the GPS has acquired the sky
position of a sufficient number of satellites to arrive at a ground position solution.
If the GPS has a good view of the sky and still has not generated any position solution within three min-
utes (it may take up to 10 minutes or more if the sky view is partially blocked.), the following trouble-
shooting procedures should be undertaken to isolate the fault:
1) Disconnect the GPS antenna cable connector from the Gemini radio and check for + 5 VDC on the
center pin of the GPS antenna connector on the radio using a Digital voltmeter (DVM). If the voltage
is present, do not reconnect the cable and proceed to step 2.
2) With the DVM, measure resistance between the shell and the center conductor of the GPS antenna ca-
ble. If it measures short circuit, the GPS antenna is defective. Replace it with a known good active an-
tenna.
3) Connect the new antenna to Gemini and wait about three minutes for the POSITION ACQUIRED in-
dicator to start flashing on G3, if not, the Gemini radio or its GPS receiver is defective.
