Receive 12.5 Khz-Band Normal Squelch Tuning - Motorola EP350 Basic Service Manual

Radio Programming and Tuning: Receiver Tuning
x. Filter 2: 15 kHz LPF
xi. Ext Load R: 24 Ω
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 "VERT/SINAD DIST/DVM COUNTER IN" on R2600 series to
the single input on audio transformer using one 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: SINAD
ii. Mode: STANDARD
c. On R2600, select "RF" under "CURSOR ZONE":
i. RF Control: GENERATE
ii. Preset: --
iii. B/W: NB
iv. Freq: Frequency Point (F1–F5) on Tuner
v. Output Lvl: -128dBm (refer to step 2 in Section 5.6.2) and increase slowly (-127dBm,
-126dBm...) (refer to step 3 in Section 5.6.2)
vi. Gen RF Out: RF I/O
vii. Modulation Type: FM
d. On R2600, select "AUD" under "CURSOR ZONE":
i. Fixed 1kHz: 1.50 kHz for 12.5kHz channel spacing and 3.0 kHz for 25kHz channel
spacing. Enable (~)
ii. Synth: Disable (x)
iii. DTMF: Disable (x)
iv. External: Disable (x)
5.6.2 Receive 12.5 kHz
1. Under the Alignment menu, select Rx Squelch, then select Squelch 12.5 kHz-band Normal.
(Figure 5-11. Rx 12.5 kHz-band Normal Squelch Tuning Window).
2. Apply a RF signal (with 1 kHz tone at 1.5 kHz deviation) for current frequency point with minimum
amplitude, -128 dBm (F1 being the first).
3. Set softpot to minimum (0) and adjust the amplitude of RF signal to the range of normal squelch
tuning (as shown in Table 5-8.) on the test equipment.
4. Adjust the softpot value by using either the Left/Right arrows on the slider or Up/Down arrows on
the Working Softpot box until the radio is totally muted.
5. Repeat steps 2–4 for F2–F5.
6. Press Program to commit the softpot values into the codeplug.
Band Normal Squelch Tuning
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5-9