Apco p-25 sound quality fine tuning – Uniden BC250D User Manual

Page 82

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APCO P-25 Sound Quality Fine Tuning

With each APCO Project 25 system, particularly at 800MHz,
the sound quality (C4FM Demodulation Threshold) may need
to be fine tuned specifically for that system. If the scanner is
not adjusted correctly, the P-25 voice transmissions will sound
robotic or unintelligible.

To adjust the sound quality to match the P-25 system you
want to monitor follow these four steps:

1. While monitoring a specific APCO P-25 frequency,

press the HOLD/MAN key.

Note: In the Trunking mode, press the TRUNK key
instead of the HOLD/MAN key.

2. Press and hold the number 9 key.

3. On Line 1 of the screen you will see SOUND

QULTY: 0050 (for example).

This shows the Sound Quality. The lower the level the
better the Sound Quality. For better Sound Quality
rotate the VFO up or down. As the threshold adjusts in
increments of 50 at the bottom of the screen watch the
Sound Quality level increase or decrease and continue
to rotate the VFO until you have achieved the lowest
Sound Quality level.

Note: • When APCO P-25 signal is not received,

SOUND QULTY: **** appears on the
display.

• You must have the BCi25D card installed and

have an APCO P-25 signal during this
adjustment.

- A chart showing the Threshold Adjustment

Range is listed below.

Threshold Adjustment Range

Note: • The above Min and Max values are

the calculated values that can be

78

SOUND QULTY:0050

867.8375 P25

Low Mid Upp

0533 1985 3342

Lower

Mid

Upper

Band

Min

Default

Max

Default

Min

Default

Max

800MHz

33

533

1883

1985

1992

3342

3842

UHF

33

633

1883

1985

1992

3342

3842

VHF

330

930

2130

2147

2264

3464

4064

BC250D 11/6/2 11:37 AM Page 78

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