Crown Low Power Transmitters - Crown Broadcast

Section 5—Adjustments and Tests ................................. 5–1
5.1 Audio Processor Adjustments ........................................................................... 5–2
5.1.1 Pre-Emphasis Selection ................................................................................ 5–2
5.1.2 Pre-Emphasis Fine Adjustment ..................................................................... 5–2
5.2 Stereo Generator Adjustments .......................................................................... 5–2
5.2.1 Separation .................................................................................................... 5–2
5.2.2 Composite Output ......................................................................................... 5–2
Using a Modulation Monitor 5–3
5.2.3 19–kHz Level ................................................................................................ 5–4
5.2.4 19–kHz Phase ............................................................................................... 5–4
5.3 Frequency Synthesizer Adjustments .................................................................. 5–4
5.3.1 Frequency (Channel) Selection ...................................................................... 5–4
5.3.2 Modulation Compensator .............................................................................. 5–4
5.3.3 Frequency Measurement and Adjustment ..................................................... 5–4
5.3.4 FSK Balance Control ..................................................................................... 5–5
5.4 Metering Board Adjustments ............................................................................. 5–5
5.4.1 Power Calibrate............................................................................................. 5–5
5.4.2 Power Set ..................................................................................................... 5–5
5.4.3 SWR Calibrate............................................................................................... 5–5
5.4.4 PA Current Limit ........................................................................................... 5–6
5.5 Motherboard Adjustments ................................................................................. 5–6
5.6 Display Modulation Calibration .......................................................................... 5–6
5.7 Voltage Regulator Adjustments ......................................................................... 5–6
5.8 Bias Set (RF Power Amplifier) ........................................................................... 5–7
5.9 Performance Verification ................................................................................... 5–7
5.9.1 Audio Proof-of-Performance Measurements ................................................. 5–7
5.9.2 De-emphasis Input Network.......................................................................... 5–7
5.10 Carrier Frequency .............................................................................................. 5–8
5.11 Output Power .................................................................................................... 5–8
5.12 RF Bandwidth and RF Harmonics ...................................................................... 5–8
5.13 Pilot Frequency ................................................................................................. 5–8
5.14 Audio Frequency Response ............................................................................... 5–9
5.15 Audio Distortion ................................................................................................ 5–9
5.16 Modulation Percentage...................................................................................... 5–9
5.17 FM and AM Noise .............................................................................................. 5–9
5.18 Stereo Separation .............................................................................................. 5–9
5.19 Crosstalk ........................................................................................................... 5–9
5.19.1 Main Channel Into Sub .............................................................................. 5–10
5.19.2 Sub Channel Into Main .............................................................................. 5–10
5.20 38–kHz Subcarrier Suppression ...................................................................... 5–10
5.21 Additional Checks ............................................................................................ 5–10
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