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Jotron AS| TR7750C: Operators Manual
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Installation Page 4-2
P/N: 84748 (G)
4.3 Installation into equipment cabinet
The units may be installed into a standard 19” subrack with a height of 3U.
The total subrack is divided into 84 TE units. The transmitter occupies 28 TE, the PSU occupies 14TE
and the receiver unit occupies 14TE.
For a transceiver this leaves a free space of 28TE available for other equipment.
Figure 4.3-1 shows some examples for installation into 19” subrack. From top to bottom the figure
shows: 6 receivers in one subrack, 2 transmitters with PSU in one subrack and 3 transmitters without
PSU (operated on DC) in one subrack.
Figure 4.3-1, Examples of various configurations
4.4 Antenna connectors
The antenna should be of good quality with regards to gain and VSWR to obtain maximum
performance. Recommended antennas can be Procom CXL-2-1LW/H (0dBd), Procom CXL-2-3C/M
(3dBd) or similar. Make sure that the VSWR on the antenna is low, and that the cable from the
transmitter to the antenna is of good quality to avoid mismatch and unnecessary losses. The antenna
used with this radio should be installed at least 260cm away from any area where people are likely to
be.
A cable loss of 1 dB is the same as reducing the power output of a 50W transmitter to less than 40W.
Similarly, a cable loss of 2 dB is the same as reducing the output power to less than 32W.
In areas were thunderstorms and lightning is a problem, surge arrestors should be mounted between
the antenna connector and the antenna cable. The arrestors should be of good quality and be
capable of handling the output power of the transmitter.
The antenna output of the transmitter is an N-type antenna connector on the back of the
transmitter. The second connector (BNC-type) is the output of the antenna switch and can be used to
connect the input of a receiver.
4.5 AC and DC connectors
Refer to section 3.4.2, 3.6.1 and 3.6.3 for voltages and connectors.
4.6 Remote signals
Several remote signals are available on the rear interfaces of the radio units.
These signals can be grouped into: Audio signals, Key signals, Data interface signals and other signals.
Note, for all interface signals, RJ45 connectors are used. As far as practically possible, the pairs used
on a standard ethernet connection are used when a signal is input/output as a pair to the radio (e.g.
audio lines). For interconnections between the transmitter and receiver, and for interconnection to a