Apco p-25 sound quality fine tuning – Uniden BC250D User Manual
Page 82
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