User manual DRAKE DIGITAL VM2551

[. . . ] VM2551 Commercial Video Modulator (For use in NTSC systems) Instruction Manual is a registered trademark of the R. L. Drake Company © Copyright 2005 R. L. Drake Company P/N: 3852551B-12-2005 2 Caution Statements WARNING: TO PREVENT FIRE OR ELECTRICAL SHOCK DO NOT EXPOSE TO RAIN OR MOISTURE !WARNING!RISK OF ELECTRIC SHOCK DO NOT OPEN CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER NO USER-SERVICEABLE PARTS INSIDE REFER SERVICING TO QUALIFIED PERSONNEL A product and cart combination should be moved with care. [. . . ] This connection is normally cabled directly to the "COMPOSITE IF IN" connector (See R2). The video carrier output level is +40 dBmV. R4 - VIDEO INPUT Connector This is the baseband video input to the IF circuits. This input accepts baseband through 4. 2 MHz video at levels from 0. 7 Vp-p to 1. 5 Vp-p. R5 - AUDIO INPUT Connector This is an unbalanced audio input to the IF circuits. This "RCA" (phono) connector input accepts 40 Hz through 15 kHz audio at a nominal level of 250 mV RMS (approximately -10 dBu). R6 - 4. 5 MHz INPUT To use this input, remove the top cover of the modulator and move jumper J2 to the ON position. Input 4. 5 MHz at R6 at a level of +37 dBmV. R7 - 600 W Convenience Outlet This outlet is unfused and must be limited to a 5A or 600 W load at 120 VAC. R8 - LINE CORD Connect the 3 wire IEC line cord to this connector. Connect to a nominal 115 VAC ±10%, 60 Hz source. Do not defeat the safety purpose of the ground pin on the line cord plug. R9 - FUSE To access the fuse, unplug line cord from the socket R8. Pull out on the tab on the upper side of the fuse holder assembly. 6 Installation RACK MOUNTING Adequate ventilation is very important in multichannel installations. Units should be spaced apart by at least one panel height wherever possible, and some air movement is advisable in enclosed rack cabinets. Excessive heat will shorten component life and modulator performance will be degraded without proper cooling. USE WITH A STEREO ENCODER An external BTSC stereo encoder may be used with the VM2551. To sett the VM2551 for a flat audio response that will accept the BTSC composite stereo input - remove the top cover of the VM2551. Observing the PCB that contians the Audio, Video, A/V Ratio, and other components, locate the small slide switch - SW2. Set switch SW2 to the Pre-emphasis OFF position. The factory default setting is Pre-emphasis ON - for mono operation. CONNECTIONS AND CONTROLS All connections to and from the VM2551 are made through the rear panel. Additional channels can be added by using additional VM2551 modulators and either multi-port combiners or combinations of two-port combiners. INSTALLATION NOTES Level adjustment provides optimum performance in multichannel installations. [. . . ] DRAKE is not responsible for damage caused by lightning, nonprofessional alterations, "acts of God" shipping damage, poor , storage/handling, etc. DRAKE will make note of any shipping damage upon receipt. Should your warranty card not be on file at R. L. DRAKE, you will need to send proof of purchase to receive warranty service. [. . . ]