120 20110-100
Gemini/PD Installation Guide
8
The auxiliary receiver antenna must be in-
stalled at least 5/8
λ
distant from the trans-
ceiver antenna.
The GPS antenna placement requires a
fairly unobstructed view of the sky. It must
also be at least two feet distant from the
transceiver antenna but it may be close to
the auxiliary RX antenna.
For the optimum antenna spacing at the fre-
quency you are using, consult system engi-
neering.
2.5.3 Antenna
Installation
1.
Route good quality 50-ohm coaxial ca-
bles (e.g. RG-223) from each of the se-
lected antenna positions to the position
where the Gemini
PD
unit is mounted.
2.
Terminate the end at each of the antenna
positions with the appropriate connector
for the antenna used and make the con-
nection.
3.
At the Gemini
PD
position, cut the three
cables to length and terminate with the
appropriate plug. For the transceiver
and the auxiliary cables, use a Mini-
UHF crimp plug using an appropriate
crimping tool. For the GPS, use a SMA
connector.
4.
Positively identify the transceiver mini-
UHF plug and connect to the left rear of
Gemini
PD
.
5.
Positively identify the auxiliary receiver
mini-UHF plug and connect to the front
left of Gemini
PD
to the RX position.
6.
Connect the SMA connector to the GPS
position below the auxiliary connector
position.
7.
Do not skip this last step, trust us; it is
an important one. To complete the in-
stallation, tie-wrap together the auxil-
iary and the GPS antenna cables at a
point about two inches in front of the
unit. It will be much easier hereafter to
correctly identify which mini-UHF plug
goes where. You DO NOT want to cross
the auxiliary plug with the transceiver
plug.
2.6 Completing the physical
Installation.
To complete the physical installation and
prior to testing Gemini
PD
:
•
Connect DC Power cable’s connector to
Gemini
PD
’s until you hear a click as the
two parts snap together.
•
Re-check that all other connections are
secure (antennas, PC, etc.)
•
Switch vehicle ignition ON.
You are now ready to check for normal op-
eration and to run the Radio Installation
Software (RIS) program for testing or trou-
ble-shooting.
2.7 Checking out Normal
operation
Check that the vehicle ignition is ON.
1-
Check for proper operation of the
Gemini
PD
’s LEDs as per Table 1 in sec-
tion 3.1.
2-
Using the RIS program (described in
section 4), and an in-line wattmeter,
check forward & reverse power to con-
firm main antenna installation.
3-
Using the RIS, check the RF link with a
base station that can be heard by using
the RIS “Ping” feature.
See paragraph 4.4.4.4
or
If user application and its base station
are available, test the installation by
going through a normal sequence of
transmitting and receiving messages.
