TVM450/S/TVM550/S TVM550II/TVM550IIS OWNER S MANUAL

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2 TVM450/S/TVM550/S TVM550II/TVM550IIS OWNER S MANUAL This manual is intended for use by the end user and qualified technicians. It includes all necessary information pertaining to TVM-series Modulator applications and installation. Changes that occur after the date of printing will be incorporated in supplemental bulletins or later editions of this manual. This document is the property of Standard Communications Corp., and embodies proprietary subject matter of Standard Communications Corp. All design, manufacture, reproduction, use and sale rights regarding the same are expressly reserved. This manual may not be reproduced without written consent from Standard Communications Corp. All copyright, patent and trade secrets are expressly reserved by Standard Communications Corp. Printed: 05/99

3 SAFETY CONSIDERATIONS AVIS RISQUE DE CHOC ELECTRIQUE NE OAS OUVRIR For user safety, one or more of the caution labels shown here may have been affixed to the side or rear panels of this equipment. The significance of the two symbols enclosed by triangles is described below: This symbol means that dangerous voltage levels are present within the equipment. These voltages are not insulated, and may be of sufficient strength to cause bodily injury if touched. The symbol may also appear on schematics. This symbol calls attention to a critical procedure, or means refer to the instruction manual for operating or service information. Only qualified service personnel are to install or service the equipment. The symbol may also appear in text and on schematics. WARNING: TO REDUCE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE! See the IMPORTANT SAFEGUARDS on the following pages for additional safety instructions. Page ii Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

4 IMPORTANT SAFEGUARDS Standard Communications Corp. (SCC) strongly advises the user to read and understand the following safety instructions prior to installing and operating this equipment. 1. Read These Instructions First All safety and operating instructions should be read before installing or operating this equipment. 2. Retain This Instruction Manual Safety and operating instructions should be retained for future reference. 3. Heed Warnings All warnings on the equipment and in this Owner's Manual should be adhered to. 4. Cleaning Unplug the equipment from the AC power outlet before cleaning. Do not use liquid or aerosol cleaners. 5. Water and Moisture Do not operate the equipment in high-humidity areas. 6. Ventilation Do not block or cover slots and openings in this equipment. These are provided for ventilation and protection from overheating. 7. Power Sources Operate this equipment only from the type of power source indicated on the rear panel. 8. Grounding or Polarization This equipment may be equipped with a polarized AC line plug (a plug having one blade wider than the other). This plug will fit into the power outlet only one way. This is a safety feature. If you are unable to insert the plug into the outlet, try reversing the plug. If the plug still does not fit, contact your electrician to replace your obsolete outlet. Do not defeat the safety purpose of a polarized plug. 9. Servicing Refer all servicing to qualified SCC personnel. Opening or removing covers may expose dangerous voltages. 10. Replacement Parts When replacement parts are required, make sure the service technician uses only replacement parts recommended by SCC. Unauthorized substitutions may result in fire, electric shock, or improper operation of the unit. 11. Safety Check Upon completion of any service or repair to the equipment, ask the service technician to perform safety checks to determine that the equipment is in proper operating condition. 12. Lightning For added protection during a lightning storm or when the equipment is left unattended or unused for long periods, unplug it from the power outlet and disconnect the cables between the equipment and the antenna subsystem. These precautions will prevent damage to the equipment that could be caused by lightning strikes or power line surges. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page iii

5 13. NOTE TO CATV SYSTEM INSTALLERS: This reminder is provided to call your attention to NEC Articles , , and that provide guidelines for proper grounding. In particular, these articles specify that the cable ground shall be connected to the building grounding system, as close to the point of cable entry as practical (see Figure 1). ANTENNA DISCHARGE UNIT (SEE NOTE 2) GROUND CLAMP TO SATELLITE RECEIVER FEED LINE GROUND CONNECTIONS (SEE NOTE 1) CONNECT TO THE NEAREST ACCESSIBLE LOCATION ON THE STRUCTURE SYSTEM 8 FEET GROUNDING ELECTRODE IN COMPLIANCE WITH NEC /NEC / NEC NOTES: 1. USE #10 AWG (5.3 MM 2 ) COPPER, #8 AWG (8.4 MM 2 ) ALUMINUM, OR #17 AWG (1.0 MM 2 ) COPPER-CLAD STEEL OR BRONZE WIRE, OR LARGER, AS THE GROUND WIRE. 2. MOUNT THE ANTENNA DISCHARGE UNIT AS CLOSE AS POSSIBLE TO WHERE THE FEED LINE ENTERS THE BUILDING. Figure 1. Typical Antenna Grounding 9001 Page iv Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

6 CONTENTS SAFETY CONSIDERATIONS...ii IMPORTANT SAFEGUARDS...iii GENERAL INFORMATION DESCRIPTION OF THE TVM450/TVM DESCRIPTION OF THE TVM550II/TVM550IIS FEATURES SPECIFICATIONS CONTROLS AND CONNECTIONS INSTALLATION AND OPERATION INSTALLATION INTERCONNECTION OPERATION TVM450/TVM550/TVM550II TVM450S AND TVM550S TVM550IIS DSG2000 OPERATION TEST TONE CHANGING TO BTSC OUTPUT OPERATION CHANGING TO COMPOSITE OUTPUT MONITORING COMMENCING OPERATION DSG2000 USER-ACCESSIBLE JUMPERS OPTION INSTALLATION CBP CBP CSG CIF CALT SAP AUDIO (TVM550IIS) AGC (TVM550IIS) BLOCK DIAGRAMS LIMITED WARRANTY DOMESTIC GOLD STANDARD SUPPORT PROGRAM INTERNATIONAL GOLD STANDARD SUPPORT PROGRAM TVM450/S/TVM550/S/TVM550II/TVM550/IIS Owner s Manual Page v

7 Contents FIGURES 1. Typical Antenna System Grounding...iv 3-1. Controls and Connections TVM Top Inside View DSG2000 Front and Rear Panels Typical Satellite Headend Installation CMA60 Front and Rear Panels Alignment Without VITS Present FCC Offset Switches CBP45 Option Package Agile IRDII, TVM450S/TVM550S and Jerrold Interconnection Changing Jumpers CBP45 Wiring and PC Board Locations CBP45 Option Package Contents CBP45-1 Package Contents Connector Sites Preparing and Installing the Cable CBP45-1 Installation CSG60 Front and Rear Panels CSG60 Cable Routing CIF450-1 Option Package Contents CIF450-1 Installation CALT45 Option Package Contents CALT45 Installation IF Combiner PC Board Component Locations Remote IF Select Installation REMOTE IF SELECT and ALTERNATE COMP IF IN Rear Panel Locations DSG2000/SAP2000 Component Locations Installing the AGC PC Board TABLES 4-1. CATV Channels and Frequencies Audio Board Jumper Functions FM Board Jumper Functions Stereo Processor Board Jumper Functions CSG60 Option PC Board Connections RF Combiner PC Board R302 Resistance AGC in OFF Mode Steady-State Output vs. Input Output Headroom Page vi Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550/IIS

8 General Information 1 GENERAL INFORMATION DESCRIPTION OF THE TVM450/S TVM550/S The TVM450, TVM450S, TVM550, and TVM550S are rebroadcast-quality, phaselocked loop (PLL)-synthesized, frequency-agile, community antenna television (CATV) and cable system television-distribution modulators. The TVM450 models range from 54 to 450 MHz, and the TVM550 models range from 54 to 550 MHz for use in domestic systems. Both modulators use an open-architecture circuit and chassis design that allows system growth with multiple field configurations. The TVM450/S and TVM550/S are designed to be the primary building blocks of an intelligent CATV distribution system. At the heart of these modulators is SCC's PLL-synthesized, dual-conversion up/down converter. The conversion process uses SCC's high-level mixing, which eliminates out-of-band noise floor and spurious emission problems. High-level mixing and superior design allow the TVM450/S and TVM550/S to meet the NTC-7-recommended specifications for a 550 MHz spectrum, without the use of external bandpass filters. The TVM550/S and TVM550/S modulators use a unique nonvolatile microprocessor tuning circuit. Available is an optional Composite IF Loop kit that allows the external input of either aural, visual, or a composite IF signal through a special loop. An alternate IF option is also available. Channels are selected with a front panel rotary switch, and the modulators can be set to only a legitimate output frequency. When a modulator is on line and the frequency output is changed, a circuit mutes the RF output until the modulator has locked onto the new output channel frequency. Front panel potentiometers for varying video modulation, audio deviation, and visual/aural carrier ratio have center detents. This type potentiometer allows the user to leave the front panel controls in their center positions while properly adjusting receiver outputs to the modulator's correct input levels. RF output is also controlled by a like potentiometer. The user can adjust the satellite receiver, for 1.0 V p-p video and 0 dbm peak audio/broadcast Television Standards Committee (BTSC) input levels, without the use of expensive test equipment. DESCRIPTION OF THE TVM550II/TVM550IIS SCC s superior circuit construction is carried over from previous TVM models. These new models differ from the preceding TVM550 models in that they sport a much-improved power supply that reduces noise and improves reliability. The TVM550II uses the CMA60 audio demodulator, while the TVM550IIS incorporates an SCC DSG2000BD digital stereo audio demodulator. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 1-1

9 General Information FEATURES Quick and easy installation Compatible with all external BTSC and RF scrambling systems Factory-calibrated front panel controls with center detents Rebroadcast-quality noise-free and spurious-emission-free RF output performance, with rock-solid PLL-synthesized surface acoustical wave (SAW)-filtered 54 to 550 MHz, frequency-agile channel output, with direct front panel readout Virtually spurious-free RF performance across the entire output ranges Seven-segment, calibrated audio deviation bar meter, with BTSC input indicator and factory-calibrated front panel controls with center detents RF output muting and visual lock indicator Visual and aural IF loop-through, compatible with all RF scrambling systems Automatic/manual FCC offsets, with RF output stability exceeding all specifications Share Assembly Program (SAP) audio and automatic gain control (AGC) available on the TVM550 series II models TVM550IIS has integrated digital stereo modulator compatible with all RF scrambling systems, as well as with baseband scrambling Gold Standard Support Program, Seven-Year Guarantee, with SCC's outstanding Lifetime Loaner Program Page1-2 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

10 Specifications 2 SPECIFICATIONS TVM450/S/TVM550/S/TVM550II/TVM550IIS SPECIFICATIONS GENERAL Primary Power Line Frequency Power Consumption TVM450 TVM550/TVM550II/TVM550IIS Operating Temperature Range 115 VAC 50 to 60 Hz 40 W (With Option) 50 W (With Option) 14 to +122 F ( 10 to +50 C) Operating Humidity Range (Noncondensing) 0 to 90% Operating Altitude Range 0 to 25,000 ft (0 to 7620 meters) Dimensions (H x W x D) Weight VIDEO CHARACTERISTICS Input Level for 87.5% Modulation Input Level Range Input Impedance Frequency Response Field-Time Waveform Distortion Short-Time Waveform Distortion Line-Time Distortion Vertical Interval Distortion 1.75 x 19 x 19 in. (44.5 x 482 x 480 mm) 14.3 lb (6.5 kg) ± 1.0 V p-p 0.5 to 1.5 V p-p 75 ohms 1.5 db 3 IRE 4 IRE 5 IRE 2 IRE Luminance Nonlinearity 5% Differential Gain (87.5% Modulation; 10 90% APL) 3% Differential Phase (87.5% Modulation; 10 90% APL) Chrominance-Luminance Intermodulation 3% Chrominance-Luminance Gain Inequality 9 IRE Chrominance-Luminance Delay Inequality 1.3 degrees ± 75 nsec Chrominance Nonlinear Gain 5% Chrominance Nonlinear Phase 3.0 Degrees Signal-to-Noise Ratio (Luminance Weighted) AUDIO CHARACTERISTICS Frequency Response (50 Hz to 90 khz) 63 db 1 db Harmonic Distortion (50 Hz to 90 khz) 1% Pre-emphasis Input Impedance 4.5 MHz Input Level ( db Sound Carrier Re. Video Carrier) Baseband Input Level for 25 khz Deviation Baseband Input Range for 25 khz Deviation Common Mode Rejection at 1 khz Hum and Noise TVM450/TVM450S (50 Hz 90 khz) 75 sec 600 ohm (balanced) 30 to 60 dbmv 0 ± 1 dbm ± 10 ± 2 db 40 db 0 db TVM550/TVM550II/TVM550IIS (50 Hz 15 khz) 0 db 4.5 MHz Subcarrier Stability 250 Hz ICPM Signal-to-Noise Ratio (Pre-emphasis ON) (50 Hz15 khz) (Video: EIA Color Bar) 1.5 degrees 60 db (Continued) TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 2-1

11 Specifications TVM450/S/TVM550/S/TVM550II/TVM550IIS SPECIFICATIONS (Continued) RF CHARACTERISTICS Frequency Range TVM450/TVM450S TVM550/TVM550S/TVM550II/TVM550IIS Output Impedance Output Return Loss TVM450/TVM450S TVM550/TVM550S/TVM550II/TVM550IIS Output Level Sound Carrier Level (Re. Video Carrier) Sound Carrier Level (Control at Center Detent Position) Stability ( MHz) Spurious Output (+60 dbmv typical) Output C/N In-Band (4 MHz BW 3 MHz from Visual Carrier) TVM450/TVM450S TVM550/TVM550S/TVM550II/TVM550IIS Output C/N Out-of-Band (4.0 MHz BW from Visual Carrier) 20/+25 MHz VSB Emission (3.58 MHz) VSB Emission (+4.75 MHz) VSB Emission (1.25 MHz) Output Mute TVM450/TVM450S TVM550/TVM550S/TVM550II/TVM550IIS IF CHARACTERISTICS Output Level (45.75 MHz) Output Level (41.25 MHz) Input Level (45.75 MHz) Input Level (41.25 MHz) w/control at Center Detent Position Output Return Loss (41.00 to MHz) Input Return Loss (41.00 to MHz) CALT45 IF INPUT KIT The CALT45 kit offers an optional IF input that can manually or automatically switch between alternate receivers/modulators. This prevents inconvenient temporary on-air down time. This kit also allows interfacing with Civil Defense switching. There are no separate specifications for this kit. Note that this kit will not work if the CIF450-1 option is installed. 54 to 450 MHz 54 to 550 MHz 75 ohm (Unbalanced) 14 db 12 db ± 60 dbmv 10 to 20 db 15 ± 1.5 db 2.0 khz 60 dbc 68 dbc 65 dbc 80 dbc 38 db 20 db 2.0 db 50 db 70 db 40 ± 1 dbmv 25 ± 1 dbmv 40 ± 1 dbmv 25 ± 1 dbmv 14 db 14 db CIF450-1 COMPOSITE IF LOOP KIT The CIF450-1 Composite Loop option allows the owner to easily insert a composite IF signal. There are no separate specifications for this option. The parts in this option package are included in the CBP45-1 option package Page 2-2 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

12 Specifications CSG60 STEREO SPECIFICATIONS AUDIO INPUT Power Requirement Power Consumption Input Level Range (at 300 Hz for 100% Modulation) Left Right Mono Input :Level at Center Detent Potentiometer Position Left Right Mono Input Impedance (Balanced) Left Right Mono Input Level Indicator (1st) (at 300 Hz Left = Right) Left Right VIDEO INPUT AND OUTPUT Input Impedance Termination Switch (S501: HIGH Combiner Switch (S502): OFF Termination Switch (S501): HIGH Combiner Switch (S502): 75 W Termination Switch (S501: HIGH Combiner Switch (S502): ON Input Level Range 4.5 MHz Output Level Termination Switch (S501): High; Combiner Switch (S502): ON 4.5 MHz OUTPUT VAC 50/60 Hz 15.5 W 10 ± 2 to + 10 ± 2 dbm 0 ± 0.5 dbm 0 ± 2 dbm 600 ohm 100 ± 5% 4.5 k ohms 75 ohms 370 ohms 0.5 to 1.5 V p-p 70 mv 4.5 MHz Frequency Accuracy ± 500 Hz Output Level (LEVEL Potentiometer Fully Clockwise) Output Level Range Output Impedance Spurious Output Pilot Signal Deviation Frequency Response Left Only or Right Only at 17 dbm Input 43 dbmv 10 db 75 ohm 60 db 5 ± 0.25 khz 50 Hz to 10 khz ± 1.0 db 10 Hz to 13 khz to 2.0 db Stereo Separation at 17 dbm Input 50 Hz to 100 Hz 30 db 100 Hz to 8 khz 20 db Distortion at 17 dbm Input 50 Hz to 7.5 khz 0.75% 7.5 khz to 13 khz 1.5% Signal-to-Noise Ratio Unmodulated Stereo Subcarrier Crosstalk Subchannel Into Main Channel Main Channel Into Subchannel 62.5 db 0.25 khz 40 db (Continued) TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 2-3

13 Specifications CSG60 STEREO SPECIFICATIONS (Continued) BASEBAND OUTPUT Output Level (Main Channel) Output Impedance (Unbalanced) Frequency Response Left Only or Right Only at 17 dbm Input 0 ± 1.0 dbmv 600 ± 5 ohms 50 Hz to 10 khz ± 1.0 db 10 Hz to 13 khz +1.0 to 2.0 db Stereo Separation at 17 dbm 50 Hz to 100 Hz 26 db 100 Hz to 8 khz 30 db 8 khz to 13 khz 20 db Distortion at 17 dbm 50 Hz to 7.5 khz 0.5% 7.5 khz to 13 khz 0.75% Signal-to-Noise Ratio CBP45 SPECIFICATIONS When operated with some earlier IF scrambling systems the modulator should be equipped with the optional CBP45 VSB filter. Installed on the IF input loop to correct for inherent scrambling process noise the CBP45 eliminates adjacent channel interference caused by the scrambling. The module may be fitted in the field or factory-installed at the time of order. To also have IF loop connectors use CBP45-1 Power Requirement Current Drain Input Impedance Output Impedance Input Return Loss Output Return Loss Gain Variation Passband Flatness 72.5 db 12 ± 0.2 V 30 ma 75 ohm 75 ohm 9 db 15 db to 1.0 db to MHz (p-p) 1.5 db at fv 39.5 MHz Ref. fv Out-of-Band Attenuation (30.5 MHz to 47.5 MHz) CBP45-1 SPECIFICATIONS The CBP45-1 kit includes the CBP45 option plus two connectors and wiring for installing the CIF450-1 Composite IF Loop option. FX450 FORMAT PROM The FX450 PROM Format option allows the owner the flexibility to use the same frequency plan format as other vendor equipment. There are no separate specifications for this kit. ± 0.3 db 20 db Page 2-4 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

14 DSG2000 SPECIFICATIONS GENERAL Dimensions (H x W x D) Weight Operating Temperature Range 1.75 x 16.6 x 14 in. (45 x 422 x 356 mm) 9.05 lb (4.2 kg) Operating Humidity Range (Noncondensing) 0 to 60% Operating Altitude Range Power Requirements Radiation Regulations Radiation Immunity Accessories Included CONNECTORS Rear Panel Audio Input Video Input Video/BTSC Output 14 to 122 ºF ( 10 to +50 ºC) 0 to 15,000 feet (0 to 4,572 meters) 110 VAC, 50/60 Hz, FCC Class B None None Eurostyle Locking Barrier Strip BNC Female BNC Female 4.5 MHz Aural Carrier Input F-type Female CONT Input Front Panel Headphone Output (Stereo) Headphone Output (SAP) Eurostyle Locking Barrier Strip (Controls AUX Input Selection) 3.5 mm Stereo Phone Jack 3.5 mm Stereo Phone Jack Specifications AUDIO INPUTS (L, R, SAP, AUX Processed on the Audio PC Board) Input Stage Type Differential Input Impedance Common Mode Input Impedance 20 k τ 2% Input Overload (20 Hz to 15 khz) 20 V p-p 2% Input Noise (20 Hz to 15 khz) Electrically Balanced Differential > 10 k τ (600 τ, Selectable via Jumper) 100 dbv VIDEO INPUTS (Processed on the Stereo PC Board) Input Stage Type Input Impedance Input Level Single-Ended 10 k Ω 5% (75 τ, Selectable via Jumper) V p-p CTL INPUT (Processed on the Front Panel PC Board Input Impedance Input Level Control Function > 10 k τ See Control Functions When CTL is grounded, AUX Input is fed to L, R, and SAP channels. When CTL is open or at +5 V, L, R, and SAP Inputs are fed to their respective channels. COMPOSITE OUTPUT (Generated on the Stereo PC Board) Output Stage Type Single-Ended Output Impedance 75 τ 5% Maximum Output Voltage into a 10 k τ Load Minimum Resistive Load Maximum Capacitive Load + 3 dbv 600 τ 100 pf (Continued) TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 2-5

15 Specifications DSG2000 (Continued) 4.5 MHz AURAL CARRIER OUTPUT (Generated on the FM PC Board) Aural Carrier Frequency Output Level (75 τ Load) Modulation Depth Output Stage Type 4.5 MHz 200 Hz 30 to 45 dbmv 100% L=R causes 50 khz Deviation (Internally Adjustable 15%; Factory set Within 1%. Single-Ended Output Impedance 75 τ 5% Maximum Output Voltage into a 75 τ Load Minimum Resistive Load Video Composite Capability STEREO ENCODER Encoding Method Separation* +39 dbmv 75 τ 50 Hz to 200 Hz 40 db 200 Hz to 2 khz 35 db 2 khz to 14.5 khz 28 db Dynamic Range (Max. L+R Input Signal at 400 Hz to 15 khz Unwanted Noise Floor, Encode/Decode) THD (Encode/Decode) at 66.7% Modulation* Internal Jumper Allows Video Input with Aural Carrier DSP Implementation of DBX-TV/Zenith Algorithm Per FCC 80 db 100 Hz 0.1% 1 khz 0.2% 10 khz 1.0% Frequency Response 50 Hz to 14 khz 0.3 db 20 Hz to 15.2 khz 3 db Pilot Frequency khz (Locked to Video Input at 2f h) 3.0 Hz (Video Lock Range) Pilot Injection khz L R Subcarrier Frequency khz (Locked to Video Input at 2f h) 6.0 Hz (Video Lock Range) L R Subcarrier Modulation L R Modulation Level Adjustments TEST TONE MODE Frequency (Bessel Null Tone) Level Injection Adjustments HEADPHONE OUTPUT Output Impedance Output Level (Open Circuit Load) Minimum Resistive Load * Measured at baseband BTSC Double-Sideband, Suppressed-Carrier AM 50 3% (L= R Causes 100% Subcarrier Modulation) None khz 0.3 Hz khz L+R Only (Mono Signal) None 300 τ 0 dbv = 100% Modulation 300 τ Page 2-6 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

16 Specifications DSG2000 OPTIONS AGC2000 (Automatic Gain Control) This option provides automatic control of the DSG2000 output. There are no separate specifications for this package. SAP2000 ENCODER (Processed on the SAP PC Board) This option allows output of SAP audio. Specifications follow: Encoding Method Dynamic Range (Max. L+R Input Signal at 400 Hz to 15 khz Unwanted Noise Floor, Encode/Decode) THD (Encode/Decode) at 66.7% Modulation DSP Implementation of DBX-TV/Zenith Algorithm Per FCC 70 db 100 Hz 0.3% 1 khz 0.5% 10 khz 0.6% Frequency Response 50 Hz to 14 khz 0.3 db 20 Hz to 15.2 khz 3 db L R Subcarrier Frequency L R Subcarrier Modulation L R Modulation Level Adjustments khz (Locked to Video Input at 5f h) 15 Hz (Video Lock Range) FM 100% (SAP Causes 15 khz Subcarrier Deviation 0.4 khz) None TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 2-7

17 Controls and Connections 3 CONTROLS AND CONNECTIONS Control/Connector Locations The TVM-series have convenient control locations provide ease of operation. Front Panel for Models with CMA60 Audio Module Refer to Figure 3-1 for the following description: 1. POWER Red LED (TVM450) or Green LED (TVM550 models). Indicates that the unit is plugged into the AC power and is operational. 2. VIDEO OVER MOD Red LED. Lights when the video depth of modulation level exceeds 87.5 percent modulation. 3. OFFSET Green LED. Lights when the selected channel has a preprogrammed FCC-assigned offset frequency. The light goes out when the OFFSET switch (27) is in the OFF or AUTO position. See rear panel callout (27) for additional switch settings. 4. RF OUTPUT Green LED. Lights when RF output is not muted, and when the phase-locked loop (PLL) is locked on-channel. The RF output is controlled by the CHANNEL SELECT switch (6) or during a power-up condition. When this LED is off, the RF output is muted to 75 dbc, eliminating an unwanted output during a tuning sequence or powering-up condition. 5. CHANNEL OUTPUT Red, dual-digit LED numeric display. Displays the current channel number being output to the RF OUT jack. 6. CHANNEL SELECT Rotary switch. Rotating this switch clockwise or counterclockwise changes the channel number sequentially higher or lower, respectively. When rotated to a different channel, RF OUT is muted for approximately four seconds. The RF OUTPUT LED goes out during this period. 7. VIDEO MODULATION Potentiometer. Adjusts the video modulation level. The center detent position is preset for an 87.5 percent depth of modulation, with a 1.0 V peak-to-peak video input signal. 8. VIDEO/AUDIO RATIO Potentiometer. The center detent position is calibrated for 15 dbc aural carrier output (maintained throughout the RF LEVEL (9) range). 9. RF LEVEL Potentiometer. Rotating clockwise or counterclockwise increases or decreases RF OUTPUT level (+45 to +60 dbmv). It is recommended that these units be operated at +58 to +60 dbmv. 10. AUDIO DEVIATION Seven-segment LED bar display. Indicates the peak aural deviation in percent. When the sixth bar of this display is lit, a representation of 100 percent or 25 khz peak aural deviation is present. The seventh bar represents overdeviation and should light only occasionally. The bar display is precalibrated with an internal 15 khz low-pass filter for accurate monaural or BTSC (L + R) indication. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 3-1

18 Controls and Connections Figure 3-1. Controls and Connections AUDIO DEVIATION Potentiometer. The center detent position is calibrated for 25 khz peak deviation on the aural output, with 0 dbm peak program audio input level. Rotating this pot changes the input levels. Page 3-2 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

19 Controls and Connections 12. BTSC INPUT Green LED. Lights when the rear panel AUDIO switch (17) or 4.5 MHz switch (18) are in BTSC or EXT positions, respectively. 13. VIDEO TEST 75-ohm BNC connector. Used to monitor the video output db RF TEST 75-ohm F connector. Used to monitor RF output. Signal level is 20 db. Rear Panel for Models with CMA60 Audio Module 15. MONO IN (+) and IN ( ) Screw terminals. A monaural audio input. 16. GND Screw terminal. An external ground connection. 17. AUDIO Slide switch. Turns pre-emphasis on or off MHz Slide switch. Selects either the internally generated 4.5 MHz carrier or an input from the EXT 4.5 MHz IN jack. 19. EXT 4.5 MHz IN 75-ohm F connector. An input for a 4.5 MHz aural carrier from an external source. The required input level is +30 to +60 dbmv. 20. VIDEO IN 75 ohm F connector. An input for the video signal. 21. RF OUT 75 ohm F connector. For the 54 to 450 MHz (TVM450) or 550 MHz (TVM550) modulator output signal. 22. REMOTE Special connector. This jack is used when the CALT45 option is installed. 23. VISUAL IF IN 75 ohm F connector. For a visual IF input from other equipment. The input level required is 40 ± 1.0 dbmv. NOTE If an IF input is used, the frequency stability of the modulator is determined by the frequency stability of the IF signal source. 24. VISUAL IF OUT 75 ohm F connector. The output of the internal Visual IF signal. Output level is 40 ±1.0 dbmv. 25. AURAL IF IN 75 ohm F connector. An input for an external Aural IF signal. The required input level is 25 ± 1.0 dbmv. 26. AURAL IF OUT 75 ohm F connector. The output of the internal Aural IF signal. The required output level is 25 ± 1.0 dbmv. 27. OFFSET Rotary switch. Manually selects the offset frequency. This allows the equipment ROM to choose the FCC offset frequency automatically when in the AUTO position, or turns the unit's ROM-pro-grammed FCC offset frequency off when in the OFF position. 28. FUSE HOLDER Houses the equipment's primary power fuse. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 3-3

20 Controls and Connections Front Panel for TVM450S/TVM550S/TVM550II Models with CSG60 Audio Module Refer to Figure 3-1 for the following description: 29. LEFT CHANNEL Seven-segment LED bar display. Indicates the peak audio deviation in percent. When the sixth bar is lit, a representation of the rear panel left input (38), when combined with the right channel input (37), produces 100 percent or 25 khz peak aural deviation. The seventh bar indicates overdeviation and should light only occasionally. The bar display is precalibrated with an internal 15 khz low-pass filter for accurate monaural or BTSC (L + R) indication. 30. INPUT LEVEL (L) Potentiometer. For adjusting the left channel audio input level. The center detent position is calibrated for 25 khz peak deviation of the aural output, with 0 dbm peak program audio level. Rotating the potentiometer varies input levels. 31. MONO INPUT LEVEL Potentiometer. For adjusting the mono channel audio input level. The center detent position is calibrated for 25 khz peak deviation of the aural output, with 0 dbm program audio input level. Rotating the potentiometer varies input levels. 32. STEREO INPUT Red LED. Lights when a BTSC stereo signal is present. 33. VIDEO LOCK Green LED. Lights when the BTSC signal is synchronized with the internal horizontal sync frequency. 34. RIGHT CHANNEL Seven-segment LED bar display. A representation of the right channel audio input level. When the sixth bar is lit, a 25 khz peak deviation output level has been achieved, indicating a 0 dbm input level. The seventh bar indicates overdeviation when lit MHz OUTPUT LEVEL Potentiometer. Adjusts the 4.5 MHz output level. 36. INPUT LEVEL (R) Potentiometer. Adjusts the right channel audio input level. This adjustment is made when a BTSC stereo format is selected. In the center detent position, the input level is preset for 0 dbm. Rear Panel for TVM450S/TVM550S Models with CSG60 Audio Module Refer to Figure 3-1 for the following description: 37. R (+) and R ( ) Screw terminals. A 600-ohm balanced, right-channel audio input for the BTSC stereo generator. 38. L (+) and L ( ) Screw terminals. A 600-ohm balanced left-channel audio input for the BTSC stereo generator. 39. MONO (+) and ( ) Screw terminals. A 600-ohm balanced monaural audio input for the BTSC generator. This is used for commercial insertion. 40. GND Screw terminal. An external ground connection for the modulator. Page 3-4 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

21 Controls and Connections 41. CONT (Control) Screw terminal. When grounded, switches from the left and right audio inputs to the monaural audio input MHz OUT 75-ohm F connector. Not used. 43. VIDEO OUT 75-ohm F connector. Not used. 44. VIDEO IN 75-ohm F connector. Video input connection. Internal (All Units) Refer to Figure 3-2 for the location of the PROM/ROM switch: FRONT ROM JU04 SU02 45 PROM POWER TRANSFORMER PU00 PM00 REAR Figure 3-2. TVM Top Inside View 45. PROM/ROM Slide switch. Selects either the FCC-assigned standard frequency format or a format stored in the optional FX450 PROM. Power to the equipment needs to be disconnected and reconnected to activate the PROM after installation. TVM550IIS with DSG2000 Digital Stereo Module See Figure 3-3 for locations of items described in this section. DSG2000 Front Panel 1. L LEVEL Potentiometer. Adjusts level for the left audio channel, which is indicated on the seven-string LED LEFT AUDIO meter (3). 2. RIGHT AUDIO Seven-string LED meter. Indicates the modulation level of the right audio channel. The first five LEDs are green, and the last two are red. The first red LED indicates 100% modulation (0 db), and the last indicates overmodulation (+3.0 db) TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 3-5

22 Controls and Connections Figure 3-3. DSG2000 Front and Rear Panels 9982A Page 3-6 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

23 Controls and Connections 3. LEFT AUDIO Seven-string LED meter. Indicates the modulation level of the left audio channel. The function is the same as in (2). 4. SAP AUDIO Seven-string LED meter. Indicates the modulation level of the optional SAP audio channel. The function is the same as in (2). 5. TEST TONE Red LED. Flashes when the test tone is activated by the TEST TONE switch (17). 6. AUDIO AGC Green LED. Lights when the AGC2000 option (if installed) is selected by the AUDIO AGC switch (18). 7. AUX AUDIO Amber LED. Lights when AUX audio is selected either by the AUX AUDIO switch (19) or by switching the rear panel terminal strip CTL terminal (32) to ground. 8. SAP LEVEL Potentiometer. Adjusts level for the SAP audio channel (when this option is installed), which is indicated on the seven-string LED SAP AUDIO meter (4). 9. R LEVEL Potentiometer. Adjusts level for the right audio channel, which is indicated on the seven-string LED RIGHT AUDIO meter. 10. MONITOR Stereo 3.5 mm phono jack. Used to monitor stereo audio. 11. SAP Stereo 3.5 mm phono jack. Used to monitor SAP AUDIO (when the SAP2000 option is installed) and AUX AUDIO. 12. VIDEO LOCK Green LED. Lights when a video lock is accomplished. 13. STR & SAP Green LED. Lights when unit is set up for stereo and SAP operation. 14. STR Green LED. Lights when the unit is set up for stereo mode. 15. MONO Amber LED. Lights when the unit is set up for MONO operation. 16. MODE Momentary pushbutton. Selects between Mono, Stereo, and Stereo & SAP modes. 17. TEST TONE Momentary pushbutton. Switches between an internal test tone and normal BTSC. The test tone introduced is a khz, Bessel nulltone, mono signal, which affects only the L+R input. The tone is used for alignment or calibration purposes. 18. AUDIO AGC Momentary pushbutton. Switches between standard audio and AGC-controlled audio (when the AGC2000 option is installed). 19. AUX AUDIO Momentary pushbutton. Switches auxiliary audio input on and off. When AUX mode is activated, the auxiliary input is fed to L, R, and SAP channels. See also (32), below. 20. LEVEL Potentiometer. Adjusts the AUX audio level. 21. LED String Seven-string LED display. Indicates the active functions. This feature is installed only in later models. Some colors change for later models: (13 now 15) and (7) change to amber, and (5) changes to red. Also, MONO (13 to 15) and STR&SAP (15 to 13) indicators change positions. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 3-7

24 Controls and Connections DSG2000 Rear Panel MHz OUT F connector. The 4.5 MHz FM output. This connector is nonfunctional in this unit. 23. VIDEO/BTSC OUT BNC connector. This connector is the output for either default or BTSC VIDEO. To change to BTSC output, see Chapter 4, page VIDEO IN BNC connector. The video signal is input here. 25. L + and Screw terminals. The balanced audio input for the left channel attaches here. 26. GROUND Screw terminals. The ground connection for the L and R channels (25 and 27). 27. R + and Screw terminals. The balanced audio input for the right channel attaches here. 28. SAP + and Screw terminals. The SAP balanced audio input attaches here (when the SAP option is installed). 29. GROUND Screw terminals. The ground connection for the SAP channel input (28) (when the SAP2000 option is installed). 30. AUX + and Screw terminals. The auxiliary balanced audio input attaches here. 31. GROUND Screw terminals. The ground connection for the auxiliary input (30) or CTL terminal (32). 32. CTL Screw terminal. When this terminal is grounded, AUX audio input is fed to L, R, and SAP channels. When it is open or at +5 VDC, L, R, and SAP inputs are fed to their respective channels. This function is the same as (19), above. Page 3-8 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

25 Installation and Operation 4 INSTALLATION AND OPERATION INSTALLATION Remove the TVM modulator from its shipping container and inspect it for any physical damage. Install the modulator into position in a 19-inch rack panel. Support the modulator while installing the four front panel mounting screws. NOTE The unit weighs approximately 15 pounds (6.8 kilograms). It may be necessary to have two people handle the modulator while the front panel mounting screws are installed. The nameplate on the rear of the modulator contains information concerning AC power requirements. Make sure that the power receptacle is of the same voltage before plugging in the AC power cord. There is no AC power On/Off switch. The POWER indicator on the front panel of the modulator will light when the power cord is plugged in. The CHANNEL OUTPUT numeric light-emitting diode (LED) will display the channel number stored in the nonvolatile read-only memory (ROM). Approximately four seconds after power is applied, the RF OUTPUT LED will light. If the selected channel has an assigned FCC offset frequency, the FCC OFFSET indicator will also light. NOTE When installing more than one TVM modulator into an equipment rack, always leave at least one rack unit between each of them for ventilation. INTERCONNECTION These modulators are designed for a headend environment. They accept separate left- and right-channel audio (TVM450S and TVM550S or TVM550IIS), monaural audio (TVM450, TVM550, or TVM550II), and composite video, via separate inputs. Each modulator provides both visual and aural IF outputs to external equipment for signal processing. The processed signals then return to the modulator s visual and aural IF input jacks. For local TV applications, each modulator receives on one TV broadcast channel and modulates on another TV broadcast channel. Baseband or IF signals can also be used. Any TVM modulator can be used in a supertrunking environment. One modulator installed at a remote antenna site drives several trunking lines. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 4-1

26 Installation and Operation Headend All TVM-series units can be configured for multiple applications in a headend installation. See Figure The first configuration uses video and monaural audio signals made available by the satellite receiver. The modulator then broadcasts on the TV channel selected on the TVM450/550/550II front panel. Figure 4-1. Typical Satellite Headend Installation The second configuration provides a video and BTSC stereo (baseband) signal to the modulator, using the CSG60 module in-line, to generate the BTSC stereo signal. The modulator then broadcasts on the TV channel selected on the TVM450/550/550II front panel. 3. The third configuration illustrates the video/stereo digital audio hookup for the TVM550IIS with its standard-equipment DSG2000BD module. 4. The fourth configuration allows direct connection between the satellite receiver and the modulator for stereo installations. This is accomplished in the TVM450S or TVM550S models, which have the CSG60 BTSC stereo generator installed as standard equipment. VIDEO A 75 ohm baseband video signal 0.5 to 1.5 V p-p (1.0 V p-p optimum), should be inserted into the rear panel VIDEO IN connector. MONAURAL AUDIO A balanced 600-ohm baseband audio signal, 10 to +10 dbm peak program (0 dbm optimum), should be connected to the rear panel screw terminals. If the audio source does not have a balanced output, use the Plus and Ground screw terminals. Page 4-2 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

27 Installation and Operation EXTERNAL BTSC A baseband 600 ohm audio signal, 10 to +10 dbm peak program (0 dbm L + R optimum), can be connected to the rear panel screw terminals. In this configuration, the rear panel Audio switch should be set to BTSC. This setting turns off the internal pre-emphasis and recalibrates the seven-segment audio indicator bar display for a BTSC input mode. (Note: the front panel BTSC LED will light.) A 4.5 MHz FM subcarrier from +30 to +60 dbmv (+35 dbmv optimum) can be inserted into the rear panel 4.5 MHz IN connection. The rear panel 4.5 MHz INT/EXT switch should be in the EXT (external) position. This defeats the internal 4.5 MHz signal and reroutes the 4.5 MHz subcarrier path. (Note: the front panel BTSC LED will light.) A MHz FM subcarrier, +25 dbm can be inserted at the rear panel aural IF LOOP IN. The rear panel 4.5 MHz INT/EXT switch should be in the EXT position. This defeats the internal 4.5 MHz signal. (Note: the front panel BTSC LED will light.) INTERNAL CSG60 BTSC The TVM450S and TVM550S modulators have a built-in CSG60 BTSC Stereo Generator for integrated BTSC/Modulator operation. At the rear panel, a Left/Right baseband audio signal, 10 to +10 dbm peak program (0 dbm optimum), balanced 600-ohm signal, can be inserted. This input can be triggered by connecting the rear panel CONT (Control) and GND (Ground) screw terminals for commercial insertion. When triggered, the Left/Right inputs are disconnected and the Mono audio signal is bridged into the Left/Right audio path, thus maintaining the BTSC spectrum. INTERNAL DSG2000BD The TVM550IIS modulator has a built-in DSG2000BD digital stereo module that provides ultraclean stereo. Similar in operation to the CSG60, this unit allows direct output of stereo signals. It can also be fitted with AGC and SAP audio. OPERATION Refer to Figure 3-1 for control locations. TVM450/TVM550/TVM550II Channel Selection 1. Rotate the CHANNEL SELECT switch until the desired channel number is displayed on the CHANNEL OUTPUT numeric display. NOTE The RF output is muted while the CHANNEL SELECT switch is rotated, until an internal phase lock is achieved. 2. Rotating the CHANNEL SELECT switch clockwise (CW) increments the channel number, and rotating this switch in a counterclockwise (CCW) direction decrements the channel number. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 4-3

28 NCTA Number Installation and Operation NOTE If the FCC OFFSET LED is lit, confirm with a frequency counter whether the automatic offset is correct for the system. If it is incorrect, rotate the rear panel FCC OFFSET switch to select the correct offset. Alternately, refer to Table 4-1. FCC Channel Number Table 4-1. CATV Channels and Frequencies Video Freq. (MHz) Audio Freq. (MHz) Offset Freq. (khz) A B C D E F G H I J K L M N O P Q R S T U V W AA BB CC DD EE FF NCTA Number FCC Channel Number Video Freq. (MHz) Audio Freq. (MHz) Offset Freq. (khz) 43 GG HH I I JJ KK LL MM NN OO PP QQ RR SS TT UU VV WW XX YY ZZ AAA BBB CCC DDD EEE FFF GGG HHH I I I JJJ KKK LLL MMM NNN OOO PPP A A A A A Page 4-4 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

29 Audio Adjustment Installation and Operation The TVM450, TVM550 and TVM550II modulators use the CMA60 Monaural Audio module. The controls and connections unique to this module are shown in Figure 4-2. PEAK AUDIO DEVIATION INDICATOR CMA60 MONO AUDIO MODULE AUDIO DEVIATION BTSC INPUT AUDIO 4.5 MHz + MONO GND MONO BTSC INT EXT EXT. 4.5 MHz IN VIDEO IN Figure 4-2. CMA60 Front and Rear Panels Inputs to this module are Video, External 4.5 MHz Aural Carrier, and Monaural Audio. Switches available on this module are AUDIO (MONO or BTSC) and 4.5 MHz (internal or external). 1. To select the Monaural Audio Input, slide the AUDIO switch to the MONO position and apply a 0 dbm input to the IN (+) and IN ( ) terminal screws on the rear of the CMA60 Monaural Audio Module. The BTSC INPUT LED lights when the AUDIO slide switch is moved to the BTSC position. Otherwise, this LED remains unlit. 2. The position of the 4.5 MHz switch is in either the INT (internal) or EXT (external) position, depending on where the 4.5 MHz aural carrier is to originate. The signal applied to the EXT 4.5 MHz IN jack should be between +35 and +60 dbmv. 3. Apply a 1.0 V peak-to-peak (p-p) video signal to the VIDEO IN jack. 4. Observe the AUDIO DEVIATION LED bar display. Adjust the AUDIO DEVIATION potentiometer through the PEAK marking on the face of the monaural module, so all the LEDs, except the PEAK, light. For BTSC audio input, adjust the meter for the same indication as Monaural Audio TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 4-5

30 Installation and Operation Video Modulation Adjustment 1. Make sure the video signal applied to the rear panel of the modulator is 1.0 V p-p. If vertical interval test signals (VITS) are not present, set the sync level for V p-p, or 40 IRE. Refer to Figure Look at the VIDEO OVER MOD LED to see if it is lit or just flickering on and off. If the LED flickers, rotate the VIDEO MODULATION adjustment CCW, to the point where modulation just peaks and does not light the LED. If the VIDEO OVER MOD LED does not light at all, turn the VIDEO MODULATION adjustment CW until the LED just starts to flicker, indicating modulation peaks. Then, back off the adjustment (CCW) until the flickering just ceases. If the VIDEO OVER MOD LED is lit continuously, rotate the VIDEO MODULATION adjustment CCW until the LED just starts to flicker. indicating modulation peaks. Then, further rotate the adjustment CCW until the flickering just ceases. MV V P-P V P-P SYNC. PULSE (0.285 V P-P) -200 IRE NOTE: IF THE VERTICAL INTERVAL TEST SIGNALS (VITS) ARE NOT PRESENT, SET SYNC. PULSE AMPLITUDE FOR V P-P. Figure 4-3. Alignment Without VITS Present Video/Audio Ratio Adjustment 1. Connect a spectrum analyzer to the 20 db RF TEST jack on the modulator front panel. 2. Observe the amplitudes of the video and audio signals. 3. Rotate the VIDEO/AUDIO RATIO adjustment until a minimum of 15 dbc is achieved Page 4-6 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS

31 Installation and Operation RF Level Adjustment 1. Connect a spectrum analyzer to the RF OUTPUT jack located on the modulator rear panel. 2. Rotate the RF LEVEL adjustment until the desired output level is achieved. The RF output is adjustable to +60 dbmv, but the unit should be operated at +58 to +60 dbmv for best results. FCC Offset Switch The FCC OFFSET switch provides the flexibility to: Select the OFF position to turn the automatic offset feature off, or to remove any offset frequencies. Select one of four manual offset frequencies, as shown in Figure 4-4. Select the AUTO position (TVM450 only) to allow the read-only memory (ROM) or PROM (programmable ROM) to select the offset as programmed for each channel. Figure 4-4. FCC Offset Switches 9038 CAUTION Care must be taken when using the FCC OFFSET switch to select a manual offset frequency (TVM450 only). If a channel is selected that has an FCC-assigned offset and the FCC OFFSET switch is set to any of the manual offset frequencies, the actual offset frequency is not as selected. For instance, if the FCC-assigned offset frequency in ROM is 12.5 khz and a manual offset frequency of 12.5 khz is selected, the resultant offset frequency will actually be 25 khz. On the other hand, if the FCC-assigned offset frequency is 12.5 khz and an offset frequency of khz is manually selected, the resultant offset frequency will be 0 khz (or no offset). See Table 4-1 to make sure the chosen FCC OFFSET switch manual position is correct. A TVM550-series unit assigns only the frequency selected. TVM450/S/TVM550/S/TVM550II/TVM550IIS Owner s Manual Page 4-7

32 Installation and Operation TVM450S AND TVM550S TVM450S and TVM550S models incorporate, as standard, the optional CSG60 BTSC Stereo Generator Module into a standard. See Chapter 5, Figure 5-7 for the panel connections unique to these models. INPUT LEVEL (L) Adjustment 3. Make sure that the input to the L (+) and L ( ) screw terminals on the rear of the BTSC Stereo Module is a balanced 600-ohm input, with a signal amplitude of 0 dbm. 4. Six LED bars will light on the LEFT CHANNEL LED bar display when the INPUT LEVEL (L) potentiometer is in the center detent position. The STEREO INPUT and VIDEO LOCK LEDs will also light. MONO INPUT LEVEL Adjustment 5. Select the MONO (+) and MONO ( ) screw terminal inputs by connecting a ground to the CONT input. 6. Make sure that a balanced 600-ohm input, with a signal amplitude of 0 dbm, is applied to the MONO (+) and MONO ( ) screw terminals. 7. Six LED bars will light on the LEFT CHANNEL LED bar display when the MONO INPUT LEVEL potentiometer is in the center detent position. The STEREO INPUT LED will not light. 4.5 MHz OUTPUT LEVEL Adjustment This potentiometer should not be adjusted because the 4.5 MHz signal is internal, and there is no way to monitor this signal externally to make an accurate adjustment. INPUT LEVEL (R) Adjustment 1. Make sure that a balanced 600-ohm input, with a signal amplitude of 0 dbm, is supplied to the R (+) and R ( ) screw terminals. 2. Six LED bars will light on the RIGHT CHANNEL LED bar display when the INPUT LEVEL (R) potentiometer is in the center detent position. The STEREO INPUT and VIDEO LOCK LEDs will light. TVM450S/TVM550S Interconnection for MVP Use These instructions are used to connect either the TVM450S or TVM550S stereo units to the Jerrold MVP scrambler system. (See Figure 4-5.) 1. Disconnect the power and remove all cables from the modulator. 2. Remove the modulator top cover (there are two screws on each side and one screw on the back). 3. Disconnect jumper J503 on the P500 board. 4. Connect the jumper loosened from J503 to the 4.5 MHz OUT connector on the unit back panel. Page 4-8 Owner s Manual TVM450/S/TVM550/S/TVM550II/TVM550IIS