Transmit 12.5 Khz Modulation Tuning - Motorola EP350 Basic Service Manual

5-6
vi. AF An1 In: FM Demod
vii. Filter 1: 50 Hz HPF
viii. Filter 2: 15 kHz LPF
ix. De-Emphasis: 750us
x. Detector: Pk+-Max
xi. AFGen1 Freq: 1.0000 kHz
xii. AFGen1 Lvl: 100mV
2. Initial setup using the R2600 series RF Communications Test Set
a. Connect "RF IN/OUT" port on R2600 series to RF adaptor on radio's antenna port using a N-
Type to BNC cable. Connect "MOT OUT" on R2600 series to "Tx MOD" on test box using a
BNC to BNC cable. Connect the rest according to Figure 5-6. Radio Tuning Setup.
b. On R2600, select "DISP" under "CURSOR ZONE":
i. Meter: RF DISPLAY
ii. Mode: STANDARD
iii. Dev: (Reading for Transmit Modulation)
c. On R2600, select "RF" under "CURSOR ZONE":
i. RF Control: MONITOR
ii. Preset: --
iii. B/W: NB
iv. Freq: Frequency Point (F1–F5) on Tuner
v. Output Lvl: 20dBm
vi. Gen RF Out: RF I/O
vii. Modulation Type: FM
d. On R2600, select "AUD" under "CURSOR ZONE":
i. Fixed 1kHz: 0.100V. Enable (~)
ii. Synth: Disable (x)
iii. DTMF: Disable (x)
iv. External: Disable (x)

5.5.3.2 Transmit 12.5 kHz Modulation Tuning

1. Under the Alignment menu, select Tx Modulation, then select Mod. 12.5 kHz (Figure 5-9. Tx
Modulation 12.5 kHz Window).
2. Press PTT Toggle and switch to PTT on the test box. This will key up the radio at the F1.
3. Read the Modulation from the Service Monitor.
4. Change the modulation setting until the Tx deviation value (in Service Monitor) lies in the range of
the 12.5 kHz channel (as shown in Table 5-7.) by using either the Left/Right arrows on the slider
or Up/Down arrows on the Working Softpot box.
5. Press PTT Toggle to dekey the radio.
Radio Programming and Tuning: Transmitter Alignment Options