User manual DRAKE DIGITAL VM1550

[. . . ] VM1550 Commercial 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 - 3857400K-3-2002 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. [. . . ] Over-Modulation LED set for 25 kHz peak deviation indication. Frequency Response: 20 Hz to 15 kHz, ± 1 dB, referenced to 75 µSec pre-emphasis curve. (20 Hz-100 kHz if preemphasis is defeated). 4. 5 MHz Intercarrier Stability: ±5 kHz, 00 C to +500 C. 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 Designation The label indicates the fixed channel output for your particular model. The VM1550 is capable of fixed channel output within the following ranges: VHF, 2-13; Lowband 1 (A8): Midband, 14-22 (A-I) and 95-99 (A5-A1); Superband, 23-36 (J-W); Hyperband, 37-44 (AA-HH); F8 - RF OUTPUT LEVEL This screwdriver adjustment permits decreasing the RF output level a minimum of 12 dB below its specified output level as the control is rotated counterclockwise. The maximum output level of +45 dBmV is set with the adjustment fully clockwise. NOTE: If an output level of less than +35 dBmV is required, add an attenuator of the appropriate value at the modulator output. Example: For an output level of +30 dBmV, add a 10 dB attenuator pad to the modulator output. Rear Panel Connections 7 MADE IN U. BY ® COMPOSITE IF RF OUT IN OUT - RISK OF FIRE -REPLACE FUSE AS MARKED AFTER DISCONNECTING UNIT FROM AC LINE CAUTION: VIDEO INPUT AUDIO INPUT FUSE 1/8A, 250V SLO-BLO 600 WATTS MAX 115V 60 Hz 10 WATTS ATTENTION: - RISQUE D'INCENDIE REMPLACEZ FUSIBLE DU TYPE INDIQUE APRES DEBRANCHER DU SECTEUR 120V, 5A R1 R2 R3 R4 R5 R6 R7 R8 R1 - RF OUT This is the modulator output. R2 - COMPOSITE IF INPUT Connector This is the composite IF input to the heterodyne converter. 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. Both input levels must be at their nominally specified levels. R3 - COMPOSITE IF OUTPUT Connector This is the composite IF output from the IF circuits. The composite IF provides a vestigial sideband filtered visual carrier at 45. 75 MHz combined with a level controlled (-15 dBc typical) aural carrier at 41. 25 MHz. This connection is normally cabled directly to the "COMPOSITE IF IN" connector (See Item `R2'). R4 - VIDEO INPUT Connector This is the baseband video input to the IF circuits. This input accepts baseband thru 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. [. . . ] 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. [. . . ]