Uniden BC785D English Owners Manual - Page 74

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 key. Note: In the Trunking mode, press the TRUNK key instead of the /HOLD key. 2. Press and hold the number 9 key. 3. On Line 1 of the screen you will see SOUND QULTY: 0050 (for example). SOUND QULTY:0050 867.8375 P25 Low Mid Upp 0533 1985 3342 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. • You can also use the and keys to adjust the sound quality. - A chart showing the Threshold Adjustment Range is listed below. Threshold Adjustment Range Band 800MHz UHF VHF Lower Mid Upper Min Default Max Default Min Default Max 33 533 1883 1985 1992 3342 3842 33 633 1883 1985 1992 3342 3842 158 658 2058 2085 2190 3590 4090 Note: • The above Min and Max values are the calculated values that can be assigned theoretically, and the values are not to guarantee the operation of the unit. • The mid threshold value will not change while adjusting the upper and lower limits. 70