Related Manuals for FM Systems FMU622CA
Summary of Contents for FM Systems FMU622CA
- Page 1 FMU622CA STEREO AUDIO PROCESSOR NARROW-BAND DUAL SUBCARRIER INPUT FM STEREO BAND OUTPUT INSTRUCTION BOOK IB 1222-02...
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Page 2: Table Of Contents
TABLE OF CONTENTS SECTION INTRODUCTION INSTALLATION & OPERATING INSTRUCTIONS SPECIFICATIONS FUNCTIONAL DESCRIPTION MAINTENANCE TUNING PROCEDURES COMPONENET LOCATOR APPENDIX B... -
Page 3: Introduction
Tuning Procedures. Remove the unit from its shipping container and inspect for shipping damage. The FMU622CA is usually shipped already mounted in a PMS610 panel (1-¾” high x 19” standard rack width). The FMU622CA is mounted in a PMS610 mainframe... -
Page 4: Specifications
When the satellite receiver is tuned to a channel that contains sub-carriers at the frequencies the FMU622CA is set for, the green “SUBCARRIER-ON” LED on the front panel will come on. This indicates that the sub carriers are being received. -
Page 5: Functional Description
19” wide rack with 17 13/16” between mounting rails, 1 ¾” high, 10 ¼” deep. The other 2 spaces in the PMS610 will accommodate additional FM Systems 600 series modules. The compact power supply in the PMS610 does not require a separate module location, as it is beside the three module locations. - Page 6 LPF, U3: U3, with C126-128, L108 and R125-127, is a 15 KHz low pass filter with low output impedance to drive the following section. SLIDING DE-EMPHASIS, U4, U5, U6, AND Q5: U4 is a precision rectifier, used to control the output drive impedance of U5 into C141 such that the variable de-emphasis curve tracks the signal level appropriately.
- Page 7 U15 is a three terminal voltage regulator, set to -18 VDC. All power used In the FMU622CA passes through U15, essentially eliminating any fluctuations due to variations of the -24 VDC supply. Most of the unit operates directly from -18 VDC, although U1 &...
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Page 8: Maintenance
FMU622CA not be re-adjusted in the field. All other adjustments require specialized test equipment. In order to avoid degrading the overall performance, do not adjust any control in the FMU622CA “By ear”. In the event of a malfunction of the unit, please contact the factory. We will generally recommend that the unit be sent to the factory for repair and recalibration. - Page 9 Measure the THD of the audio oscillator FM generator combination. It should be less than 0.5%, if not, do not attempt to reduce the FMU622CA demodulator distortion, as the adjustment may add distortion in an attempt to cancel that of the test equipment.
- Page 10 There are two tracking adjustments in each channel of the FMU622CA, the first is to set the low frequency through level to a standard, the second is to set the high frequency through level to the same level at 100% modulation.
- Page 11 STEREO MULTIPLEX ALIGNMENT: The stereo multiplex circuitry is best aligned with two matched FM sub-carrier generators, one for the left channel and another for the right. However, it is possible to accomplish the alignment with just one, that procedure will be described here, as most service people have only one FM generator available.
- Page 12 FM CHANNEL FREQUENCY CHANGE: The FMU622CA RF output is controlled by a phase lock loop (PLL) automatic frequency control system. As long as the average frequency of the FM carrier is equal to the reference frequency, the red “OFF FREQ” LED on the front panel will not light.
- Page 13 SET FREQUENCY SWITCHES: Look up the settings for the Frequency Switches (SW501) in the accompanying table and carefully set each of the ten or fourteen switches. If the new frequency is outside the range of this table, it may be set as detailed in Section 4.0.0. CENTER AFC RANGE: After the switches are set to the new frequency, press pushbutton SW516 “AFC TEST”...
- Page 14 EXAMPLE (Assume that applicable increment for highest switch is 102.4 MHz): If 88.5 is the desired (target) frequency: SW 10, 102.4 MHz, is over target, leave closed. The total is still 0. SW 9, 51.2 MHz, is under target, open it. The total is now 51.2. SW 8, 25.6 MHz, added to 51.2, is under target, open it.
- Page 15 AN X INDICATES NUMBER SIDE OF ROCKER SWITCH IS UP. SET SWITCHES TO THE DISIRED FREQUENCY AND FOLLOW THE DIRECTIONS IN THE INSTRUCTION BOOK. 1 = STRAP CUT. FREQ MHz 1 STRAP 88.0 88.1 88.2 88.3 88.4 88.5 88.6 88.7 88.8 88.9 89.0...
- Page 16 AN X INDICATES NUMBER SIDE OF ROCKER SWITCH IS UP. SET SWITCHES TO THE DISIRED FREQUENCY AND FOLLOW THE DIRECTIONS IN THE INSTRUCTION BOOK. 1 = STRAP CUT. FREQ MHz 1 STRAP 92.0 92.1 92.2 92.3 92.4 92.5 92.6 92.7 92.8 92.9 93.0...
- Page 17 AN X INDICATES NUMBER SIDE OF ROCKER SWITCH IS UP. SET SWITCHES TO THE DISIRED FREQUENCY AND FOLLOW THE DIRECTIONS IN THE INSTRUCTION BOOK. 1 = STRAP CUT. FREQ MHz STRAP 96.0 96.1 96.2 96.3 96.4 96.5 96.6 96.7 96.8 96.9 97.0 97.1...
- Page 18 AN X INDICATES NUMBER SIDE OF ROCKER SWITCH IS UP. SET SWITCHES TO THE DISIRED FREQUENCY AND FOLLOW THE DIRECTIONS IN THE INSTRUCTION BOOK. 1 = STRAP CUT. FREQ MHz 1 STRAP 100.0 100.1 100.2 100.3 100.4 100.5 100.6 100.7 100.8 100.9 101.0...
- Page 19 AN X INDICATES NUMBER SIDE OF ROCKER SWITCH IS UP. SET SWITCHES TO THE DISIRED FREQUENCY AND FOLLOW THE DIRECTIONS IN THE INSTRUCTION BOOK. 1 = STRAP CUT. FREQ MHz STRAP 104.0 104.1 104.2 104.3 104.4 104.5 104.6 104.7 104.8 104.9 105.0 105.1...
- Page 20 APPENDIX B PMS610 MAINFRAME AND POWER SUPPLY INSTRUCTIONS The PMS610 is a mainframe power supply for mounting FM SYSTEMS 600 series equipment. Up to three circuit board modules may be accommodated. These modules may be readily installed in the field with common hand tools, no soldering is required.
- Page 21 Push any LEDs (Light Emitting Diodes) straight into the appropriate mounting holes. (See instructions for the particular module being installed). Insert only until the dark collar around the colored LED is flush with the front panel, the collar must not protrude, in order to avoid interfering with the new nameplate.