Midland 91-1060-91-1110, Дополнение к руководству по обслуживанию

Страница: 14 / 62

Alignment Procedures
Low Current Base Tech 3.5
8) Maximum Analog Deviation Limiting Alignment (Base Station and Repeater)
a) Press the “#” key on the Front Panel until second line of the LCD displays “ANALOG DEVI.”
b) Apply a 1 kHz tone at the microphone input at a level required to obtain 60% system deviation. Use
pins 1 and 2 (pin 2 = ground).
c) Activate PTT by grounding pin 4 of the microphone jack. Note the audio generator level setting.
d) Increase the audio level by 20 dB (equivalent to 10x voltage increase).
e) Press the “A” key to increase or the “B” key to decrease the system deviation until it is just below
±4.5 kHz without CTCSS modulation or ±4.7 kHz with CTCSS modulation (25 / 30 kHz channel
spacing) or ±2.3 kHz without CTCSS modulation or ±2.5 kHz with CTCSS modulation (12.5 / 15
kHz channel spacing). The radio is in limiting at this point, so distortion will be higher according to
the service monitor. Deviation should be measured with at least a 50 Hz to 15 kHz filter enabled (no
higher than 20 kHz).
f) Deactivate the transmitter.
9) Analog Repeater Deviation Alignment (This should be checked AFTER Step 8 has been accomplished)
a) Press the “#” key on the Front Panel until second line of the LCD displays “REPEAT DEVI.”
b) Set the radio to a channel programmed for repeat mode (wide or narrow band).
c) Inject a -47 dBm ± 3 dB RF signal modulated with a 1 kHz tone into the receiver input at 60%
system deviation. Enable sub-audible signaling if the radio (repeater) is configured as so.
d) At this time, the radio (repeater) should be transmitting.
e) Measure the transmitter deviation level. Enable audio filtering of 300 Hz to 3 kHz if sub-audio
signaling is present. If sub-audio signaling can not be filtered, set the radio to a channel
programmed without sub-audio signaling enabled, and disable sub-audible signaling on the signal
source.
f) Press the “A” key to increase or the “B” key to decrease the repeater transmitter deviation until it is
60% ± 5% system deviation.
g) Remove the RF signal.
10) Analog CWID/DTMF Deviation Alignment
a) To best perform this alignment, it is preferred to program a radio channel to the desired operational
parameters intended for daily operation. It is typical that this channel is to also transmit the normal
CWID tone sequence. If no channel has been programmed as described, continue with the
remaining steps.
b) Press the “#” key on the Front Panel until second line of the LCD displays “TONE DEVI.”
c) Activate PTT.
d) Press the “A” key to increase or the “B” key to decrease the CWID transmitter deviation until it is
40% ± 5% system deviation.
e) Deactivate PTT.
© 2012 Midland Radio Corporation
10