EFJohnson 988X SERIES Two-Way Radio User Manual


 
INSTALLATION
2-7
February 2001
Part No. 001-9800-001
Figure 2-6 Data Cable Installation (-001 Cable Shown)
Strain Relief
Accessory
J301
J701
Two User-Definable Wires
Pigtail Cable
Data Pigtail Cable
installed. Then install the mounting bracket using
the included self-tapping screws or other screws if
desired.
2. Install the control unit in the bracket using the
included knobs and vulcanized washers (the
washers are installed between the bracket and
control unit).
3. Install the included microphone hanger in a conve-
nient location using the included sheet metal screws
or other screws. For proper operation of functions
such as the monitor mode and scan, the hanger must
be connected to chassis ground. If required, ground
the hanger using the included ground wire.
2.6 USING AN EXTERNAL SPEAKER
Power output with the internal 8-ohm speaker in
the front panel or remote control unit is approximately
3 watts. For up to 5 watts of power, a 4.7-ohm external
speaker can be used. This speaker is plugged into the
external speaker jack on the back of the transceiver.
This is a standard 1/8”, two-conductor phone jack. The
internal speaker is automatically disabled when an
external speaker is used.
The impedance of the external speaker must not
be less than 4.0 ohms. Using a speaker with an imped-
ance less than 4.0 ohms could result in audio ampli-
fier U306 overheating and does not provide 5 watts of
power. Therefore, to allow for tolerances, a speaker
with a nominal impedance of 4.7 ohms is recom-
mended. The E.F. Johnson remote speaker listed in
Figure 2-1 or Table 1-3 meets this requirement. This
speaker has a 6-ft cable, and in some applications
(such as remote mounting) an extension cable may be
required to connect it to the transceiver.
2.7 DATA CABLE INSTALLATION
CAUTION
DO NOT apply power a transceiver that has one of the
data cables installed without first properly terminating
the wires of that cable. These wires carry differing
potentials and transceiver damage may result if they
inadvertently contact each other.