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 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. The lightning flash with arrow head symbol, within an equilateral triangle, is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. [. . . ] Frequency Response: 50 Hz to 15 kHz, ±1dB Total Harmonic Distortion: 0. 5% maximum. Hum and Noise: -60 dB minimum, referenced to 25 kHz peak deviation. COMPOSITE IF LOOP Output Level (V carrier): +28 dBmV ± 2 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. 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. 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. R3 - COMPOSITE IF OUT Connector This is the composite IF output from the IF circuits. [. . . ] Be sure to include your street address which will be needed for UPS return. UPS Surface (Brown Label) takes 7-10 days to reach us depending on your location, Blue takes 2-3 days. Red is an overnight service. Send the unit in a way that it can be traced if we can't verify receipt of shipment. Our return shipping policy is that we will return it UPS Brown if received Brown or by US Mail, it will be returned Blue if received Blue or Red--or it will be returned however you prefer if you furnish the return cost for the method you select. [. . . ]