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LBI-31482
EXAMPLE 1 - Group Call Code 07 (also code 27 and
37):
The digit "0" in Table 5 shows that Tone B is in Tone
Group 2 along with 20 to 29 and 30 to 39. Tone number 7 in
Tone Group 2 is 832.5 Hz (See Table 4).
EXAMPLE 2 - Group Call Code 98 (also code 48 and
88):
The digit "9" in Table 5 shows that Tone B is in Tone
Group 4 along with 40 to 49 and 80 to 89. Tone number 8 in
Tone Group 4 is 496.8 Hz.
Table 5 - Group Call Tone Groups (TG)
GROUP CALL
TONE GROUP
CODE NUMBER
(Tone B)
00 - 09
TG2
10 - 19
TG1
20 - 29
TG2
30 - 39
TG2
40 - 49
G4
50 - 59
TG5
60 - 69
TG1
70 - 79
TG5
80 - 89
TG4
90 - 99
TG4
6
DISASSEMBLY
To gain access to the receiver board for servicing:
1.
Loosen the two screws in the back cover and while
applying pressure to the lower portion of the front
cover, lift off cover.
2.
With the speaker facing down, carefully loosen the
board in the front cover, starting with the bottom of
the printed board first.
3.
Carefully turn the Pager over in the palm of the
hand (speaker facing up) and lift off the front
cover.
When replacing the board in the case, hold the case with
the speaker grill facing down and insert the Mode Select
switch, Reset switch and the Power/Volume switch into their
appropriate positions in the top of the case first. Make sure
the speaker is properly located. Then gently press the board
up into the case. Snap the back cover back into place and
tighten the two securing screws.
ALIGNMENT PROCEDURE
ALIGNMENT PROCEDURES
(33-50 MHz)
EQUIPMENT REQUIRED:
1.
Multimeter.
2.
SINAD Meter or Distortion Analyzer (with floating instrument circuit ground).
3.
RF Signal Generator (two required).
4.
2-Tone Generator.
NOTE
Use short, direct cabling and wiring to keep RF interference to a minimum.
STEP
1.
Construct a 50 ohm coaxial cable (RG58-type) with a BNC connector on one end and clip leads on the other end.
2.
Remove printed hoard assembly from case and insert fully charged batteries.
3.
Connect the shield clip lead of the coaxial cable to the negative battery terminal. (This terminal connects directly
to chassis ground.)
4.
Place the center conductor lead of the coaxial cable beneath the pager and lay pager flat on work bench. (cable
lead should be insulated from radio circuitry.)
5.
Connect BNC end of cable to the RF Signal Generator.
6.
Turn of the Pager and adjust squelch control RV52 until the pager is fully un-squelched.
7.
Set unmodulated RF signal generator to desired pager operating frequency. Keeping the RF generator exactly on
frequency. Slowly turn up the RF output of the generator until the pager starts to quiet.
8.
Set another unmodulated RF generator to 10.7 MHz. Loosely couple this 10.7 MHz signal into coil form of L7.
9.
Adjust L5 for desired frequency by tuning until a zero beat between the two signals is heard in the speaker.
10.
Remove the 10.7 MHz signal. Connect an RF millivolt meter to TP1 and adjust L6 for maximum output on the
meter.
11.
Modulate the RF generator with 1 kHz tone at 3 kHz deviation. Set the generator's output so that an audible level
of approximately 12 dB SINAD is heard at the speaker.
12.
Adjust L2, L3 and CV1 for best quieting. Reduce the generator output while tuning to maintain an audible level
of approximately 12 dB SINAD.
13.
Adjust L7 to mid-range.
13.1
Connect the probe of the RF millivolt meter to TP1. Note thereading on the meter. Next, increase the radiated,
un-modulated RF input to the pager by turning up the generator output until a significant increase in meter
reading is obtained. Then adjust L4 for maximum reading on the meter. (If two peaks are observed, tune to the
one nearest the top of the coil form.)
LBI-31482
PROCEDURE
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