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120 20110-003  PRELIMINARY

Gemini/PD   Technical Manual

9

TRANSMITTER

UHF

Power output

10-40 watts

Duty cycle

20% @ full power, 30 seconds maximum transmit time

Conducted Spurious

-75 dBc (-38 dBm @10 W) typical

Frequency stability

1.5 ppm

FM hum and noise

-45 dB max (25 kHz)

Attack time

< 10 ms

MODEM OPERATION

Interface

EIA RS-232C

Operation

Simplex/half duplex

Data rates

4800 b/s

9600 b/s

19200 b/s

Modulation type

DRCMSK

DRCMSK

DRCMSK

Packet Error Rate

(for < 1% error)

better than –110 dBm at 9600 b/s half channel

better than –115 dBm at 9600 b/s full channel

better than –112 dBm at 16000 b/s full channel

better than –109 dBm at 19200 b/s full channel

Protocol

Dataradio Proprietary

DISPLAY and CONTROLS

2 status LEDs

RX/TX, PWR

FCC / IC
CERTIFICATIONS

FCC

IC (DOC)

UHF

EOTGPDA

773195525A

800 MHz

900 MHz

Summary of Contents for Gemini PD

Page 1: ...Service Manual version 0 03 PRELIMINARY The entire contents of this manual and the Radio Service Software described in this manual are copyright 1998 by DATARADIO Inc Copyright DATARADIO Inc November...

Page 2: ...RONT REAR PANELS 2 2 1 1 LED Indicators 3 2 2 DTE PORT INTERFACE 3 2 2 1 RS 232 Interface Signal Levels 3 3 ADJUSTMENTS AND MAINTENANCE 4 3 1 OVERVIEW 4 3 1 INTENDED AUDIENCE 4 3 2 EQUIPMENT REQUIRED...

Page 3: ...ii What s New in Version 0 02 GPS Diagnostics procedure History Version 0 1 First preliminary version Version 0 2 Unit specification revised Typo correction...

Page 4: ...arious RS 232C interface signals Most user equipment as well as PCs are wired as DTE See also DCE GCU Gemini Control Unit board Gemini PD High specs mobile radio modem PD Parallel decode HDX Half Dupl...

Page 5: ...tic Vehicle Location AVL Using a GPS receiver determines posi tion speed and direction of fleet mem bers The Gemini PD is made up of a main transceiver and a auxiliary receiver for Parallel Decode PD...

Page 6: ...Technical Support for service in formation before returning equipment A Technical Support representative may sug gest a solution eliminating the need to return equipment 1 6 1 Factory Repair When retu...

Page 7: ...om Gemini PD hand shaking 9 AUX auxiliary input to Gemini PD panic line input port 3 It may be activated by dry contact pull up to the port s DSR output It may also tolerate user pull up to external 1...

Page 8: ...ments 3 4 1 Preliminary Verification Before performing any adjustment verify the per formance of the unit as shown in the Table 1 Important note Before proceeding make sure that the service monitor ha...

Page 9: ...sing RSS adjust TX deviation 4 Set the service monitor to generate a 80 dBm signal on the selected receive frequency The signal should be modulated with a 1 0 kHz tone Open the top cover to access the...

Page 10: ...ps screw from the unit top cover 2 Remove the top cover by lifting it from the rear 3 Slide the cover out of the case 24 23 2 1 J400 13 6Vdc Power connector Main Antenna connector Aux Receiver Antenna...

Page 11: ...ken 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 DVM If the voltage i...

Page 12: ...urrent at 13 6 VDC 15 A TX RX separation 5 MHz typical Nominal Dimensions 7 050 D x 6 000 W x 2 0000 H Weight 3 5 lbs RF input output Impedance 50 ohms nominal RF connector Main TX RX mini UHF female...

Page 13: ...ION Interface EIA RS 232C Operation Simplex half duplex Data rates 4800 b s 9600 b s 19200 b s Modulation type DRCMSK DRCMSK DRCMSK Packet Error Rate for 1 error better than 110 dBm at 9600 b s half c...

Page 14: ...120 10503 201 ii T 96S Technical Manual...

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