User manual DRAKE DIGITAL VM2050

[. . . ] VM2050 Commercial T Channel Video Modulator (For use in NTSC systems) Instruction Manual ® is a registered trademark of the R. L. Drake Company © Copyright 2002 R. L. Drake Company P/N: 3852412C-2-2002 Printed in U. S. A. 2 Caution Statements WARNING: TO PREVENT FIRE OR ELECTRICAL SHOCK DO NOT EXPOSE TO RAIN OR MOISTURE A product and cart combination should be moved with care. Quick stops, excessive force and uneven surfaces may cause the product and cart combination to overturn. [. . . ] IF Output Impedance: 75 Ohms, return loss greater than 15 dB. Isolation: Greater than 60 dB. VIDEO Input Level for 87. 5%: 1 Vp-p ±3 dB manual gain adjustment and front panel modulation indicators. Input Impedance: 75 Ohms, return loss of 26 dB minimum. F5 - MODULATION Indicators (Audio) The green LED will be turned on continuously for peak deviations of approximately 2. 5 kHz (10% of 25 kHz maximum) or greater. An overmodulation condition is noted with the red LED turned on continuously. The AUDIO LEVEL control should be set to a point where the red LED just remains off (see item F4). F6 - A/V RATIO Control This screwdriver adjustment varies the level of the aural carrier over a range from 10 to 20 dB below the visual carrier. The aural carrier should be adjusted to approximately 15 dB below the visual carrier (normal operation). Clockwise rotation increases the aural carrier level and thus decreases the A/V ratio. F7 - CHANNEL Switch These pushwheel switches allow the selection of the desired operating channel from T07 to T14. See Table 1 CHANNEL ASSIGNMENTS for the list of corresponding operating frequency for each channel number. F8 - OUTPUT ENABLED Indicator Lights to indicate a valid channel is selected. The RF output is switched off for any invalid channel settings or other conditions that would cause the unit to operate on an invalid frequency. F9 - RF OUTPUT LEVEL Control This screwdriver adjustment varies the RF OUTPUT level. Clockwise rotation increases the level. Rear Panel Connections 7 R7 MADE IN THE U. S. A. BY R RF O UT P UT IN C O M P O S IT E IF OUT AUDIO I N P UT VIDEO I N P UT CAUTION: - RISK OF FIRE - REPLACE FUSE AS MARKED AFTER DISCONNECTING UNIT FROM AC LINE. ATTENTION: - RISQUE D'INCENDIE REMPLACEZ FUSIBLE DU TYPE INDIQUE APRES DEBRANCHER DU SECTEUR. FUSE 4/10 A , 250 V SLO - BLO 115 VAC , 60 Hz 25 WATTS IF LOOP SERIAL # VISUAL: 45. 75 MHz AURAL: 41. 25 MHz FUSE R1 R2 R3 R4 R5 R6 Figure 2 R1 - RF OUTPUT This is the modulator output. R2 - COMPOSITE IF IN Connector This is the composite IF input to the synthesizer circuits. The composite IF has both the aural and visual IF combined. This connection is normally cabled directly to the "COMPOSITE IF OUT" connector (see item R3). This external IF loop allows the use of accessories such as scramblers or alternate video sources. Note that accessory equipment must also have the visual carrier at 45. 75 MHz and the aural carrier at 41. 25 MHz. [. . . ] Should your warranty card not be on file at R. L. DRAKE, you will need to send proof of purchase to receive warranty service. Typically, a copy of the invoice from an R. L. The warranty is for the original owner only and is not transferable. Warranty 11 Warranty Three Year Limited Warranty R. L. [. . . ]