DRAKE VMR860AG Instruction manual

DRAKE VMR860AS is a high-quality audio/video modulator that allows you to convert and combine audio and video signals into a single RF signal that can be transmitted over a coaxial cable to a TV or other display device. It supports a wide range of input and output options, making it compatible with most audio and video sources and display devices. Some of the key capabilities of the DRAKE VMR860AS include:

Standard CATV channels: The VMR860AS can modulate and output standard CATV channels 2 through 135, making it ideal for use in cable TV systems or for distributing video signals within a home or office building.

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VMD860AG VIDEO MODULATOR 1 2 FRONT PANEL CONTROLS and INDICATORS

F1 F2 F3 F4 F5 F6 F7 F8 F9 F10

This instruction manual also is applicable to the

VMD860AS, VMR860AG, and VMR860AS.

The AS models include a built-in BTSC stereo audio encoder to provide stereo audio.

The VMR models are electrically identical to the

VMD units except that they are designed for

19" rack mounting.

In this manual, only the VMD860AG model is discussed except where there are differences. Any differences will be explained.

The R.L. Drake VMD860AG family of Audio-

Video Modulators includes high quality, vestigial sideband units with synthesized visual and aural carriers. The frequency agile units allow front panel pushwheel switch selection of standard CATV channels 2 through 135, CATV subband channels, T7 through T14, or VHF/

UHF TV channels 2 through 69. Additionally,

IRC or HRC CATV channel plans may be selected after moving an internal jumper.

Aeronautical channels are offset positive with a tolerance of ±5 kHz as required by FCC rules.

The heterodyne conversion system, in conjunction with the use of a SAW filter, ensures optimum vestigial selectivity for adjacent channel headends.

Broadband noise and in-channel noise are reduced to a very low levels to provide excellent performance in multichannel CATV headend environments.

The modulators are designed to accept any standard audio/video source such as NTSC video and audio baseband signals from a satellite receiver, TV camera, videotape recorder, TV demodulator, or similar signal source. The VMD860AS and VMR860AS can accept stereo audio inputs and produce a

BTSC stereo audio signal.

When stereo audio is required, the preferred method of providing a BTSC stereo signal is to use the VMD860AS or VMR860AS model. No special setup or test equipment is required.

Also, field-defeatable audio pre-emphasis in the AG models allows transmission of BTSC encoded baseband stereo audio signals from an external BTSC stereo encoder, such as the

Drake MMTS20. Optimum performance requires proper test equipment for setup with external

BTSC encoders.

The AG models will accept either mono or stereo inputs and output a mono audio signal with left and right inputs being summed in the modulator.

The modulators are designed to accept standard (negative sync) polarity video at 0.6

to 1.5 Vp-p level. All level controls are located on the front panel for ease of operation. Audio and video overmodulation indicators are provided. Output level is +45 dBmV and is adjustable downward.

FCC predistortion is provided in the video IF.

® is a registered trademark of the R.L. Drake Company

F1 - POWER/Error Indicator

Lights when the unit is connected to the required source of DC power via the rear panel

DC INPUT connector. A flashing condition indicates an invalid channel setting or other conditions that would cause the unit to operate on an invalid channel. The RF output is switched off for flashing (ERROR) conditions.

F2 - VIDEO Level Control

The setting of this screwdriver adjustment determines the video modulation level.

Clockwise rotation increases the modulation depth.

F3 - Video OVER MODULATION LED

With a video input applied, adjust (F2) until this indicator just illuminates, then set just below this point.

F4 - AUDIO Level Control

The setting of this screwdriver adjustment determines the aural carrier deviation. Clockwise rotation increases the carrier deviation.

F5 - Audio OVER MODULATION LED

With audio applied, adjust (F4) until this indicator just illuminates on peaks.

F6 - A/V RATIO Control

This screwdriver adjustment varies the level of the aural carrier over a range from 12 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.

Figure 1

F7 -T CHANNEL Switch

Set this switch to the "T" channel setting to enable "T" channel coverage. Use the Channel

Number switch (F9) to select 7 - 14. For normal

CATV or broadcast TV channels, this switch must be set to the right to enable selection by the mode switch (F8).

F8 - Mode Switch

Sets the type of channel, CATV or Broadcast

TV (“BCTV”). This switch does not function if switch (F7) is in the "T" channel position. The last position of the switch (“+100”) sets a leading “1” for CATV channels 100 through 125.

See Item (F9) for setting the channel number.

Example 1:

Setting for CATV channel "125"-

T CHANNELS

CATV +100

CATV

BCTV

Example 2:

Setting for CATV channel "25"-

CATV +100

CATV

BCTV

2 5

CHANNEL

2 5

T CHANNELS CHANNEL

F9 - CHANNEL Number Switch

Sets the desired operating channel for standard

CATV channels 02 through 135, "T" channels

T7 through T14, or Broadcast TV channels 02 through 69. See Item (F8) which sets the type of channel (CATV or Broadcast TV) and sets the leading “1” for CATV channels 100 through

125.

F10 - RF OUTPUT LEVEL

This screwdriver adjustment permits decreasing the RF output level a minimum of 10 dB as the control is rotated counterclockwise. Set the control for a desired output level.

3 REAR PANEL CONNECTIONS

R1 R2 R3 R4 R5

RF OUT AUDIO IN VIDEO IN POWER

LEFT RIGHT

Figure 2

R1 - RF OUTPUT Connector

This is the modulator output.

R2 and R3 - AUDIO INPUT Connectors

These "RCA" (phono) connector inputs accept baseband audio from 250 mVrms to 3 Vrms levels. NOTE: In the AG models, an internally selected jumper can defeat the audio preemphasis for use with a stereo encoder. See

Diagram on page 4.

For AG mono models, the inputs from the left and right jacks are internally summed. Input can be from a stereo source to both inputs or from a mono source to just one of the inputs.

For the AS stereo models, R2 and R3 are the left and right stereo channel inputs. A mono source connected to an AS stereo unit should be input to both connectors using a "Y" cable.

R4 - VIDEO INPUT Connector

This is the baseband video input to the IF circuits. This input accepts baseband input levels from 0.6 Vp-p to 1.5 Vp-p.

R5 - POWER / DC INPUT Connector

This connector accepts the appropriate mating

DC power cable from the supplied AC adapter.

4 SETTING THE INTERNAL JUMPERS

ACCESSING THE JUMPERS

- First, make certain the unit is disconnected from its power source.

- Next, remove the four #4 screws from each side of the top cover. Save the screws for later reassembly.

- Carefully remove the top cover by lifting it upward from the chassis. The jumpers are now accessible for setting as desired.

JUMPER FUNCTIONS

Refer to the INTERNAL JUMPER FUNCTIONS diagram for a brief explanation of the two jumpers used in the jumper settings.

Refer to the INTERNAL JUMPER SETTINGS

Diagram for proper jumper placement of the desired mode.

INTERNAL JUMPER FUNCTIONS

Audio Pre-emphasis jumper shown in the ON position.

Shown in standard configuration

(no jumper). Add jumper for IRC or

HRC.

INSTALLATION NOTES

Level adjustment provides optimum performance in multichannel installations.

The modulator outputs should be checked periodically with a spectrum analyzer or signal strength meter to maintain a ±1 dB variation of adjacent channel carriers. Aural/Visual (A/V) ratios should be held to -15 dB or less. The output ‘RF’ and ‘A/V (Ratio)’ controls are used respectively to make these adjustments.

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 mandatory in enclosed rack cabinets.

Excessive heat will shorten component life and modulator performance will be degraded without proper ventilation.

Front of VMM860AG With Cover Removed

5 CATV CHANNEL OUTPUT FREQUENCIES

TABLE 1: CATV

CHANNELS

CATV +100

CATV

BCTV

Output Channel

Switch Setting

T CHANNELS

Visual Carrier

Frequency (MHz)

Frequency

Offset (kHz)

373.25

379.25

385.25

391.25

397.25

403.25

409.25

415.25

421.25

427.25

433.25

439.25

445.25

451.25

457.25

463.25

469.25

475.25

481.25

487.25

493.25

277.25

283.25

289.25

295.25

301.25

307.25

313.25

319.25

325.25

331.25

337.25

343.25

349.25

355.25

361.25

367.25

139.25

145.25

151.25

157.25

163.25

169.25

217.25

223.25

229.25

235.25

241.25

247.25

253.25

259.25

265.25

271.25

55.25

61.25

67.25

77.25

83.25

175.25

181.25

187.25

193.25

199.25

205.25

211.25

121.25

127.25

133.25

+12.5

+25

+12.5

NONE

+12.5

NONE

±12.5

NONE

+12.5

NONE

CATV +100

CATV

BCTV

T CHANNELS

Output Channel

Switch Setting

Visual Carrier

Frequency (MHz)

499.25

505.25

511.25

517.25

523.25

529.25

535.25

541.25

547.25

553.25

559.25

565.25

571.25

577.25

583.25

589.25

595.25

601.25

607.25

613.25

619.25

625.25

631.25

637.25

643.25

91.25

97.25

103.25

109.25

115.25

Frequency

Offset (kHz)

NONE

+25

CATV +100

CATV +100

CATV

BCTV

109

110

111

112

113

114

100

101

102

103

104

105

106

107

108

115

116

117

118

119

120

121

122

123

124

125 cont'd on page 6

T CHANNELS

739.25

745.25

751.25

757.25

763.25

769.25

775.25

781.25

787.25

793.25

799.25

649.25

655.25

661.25

667.25

673.25

679.25

685.25

691.25

697.25

703.25

709.25

715.25

721.25

727.25

733.25

NONE

6 CATV & BROADCAST CHANNEL OUTPUT FREQUENCIES

TABLE 1: CATV + 100

cont'd.

CATV +100

CATV

BCTV

TABLE 3: BCTV

CHANNELS, cont'd.

T CHANNELS

CATV +100

CATV

BCTV

T CHANNELS

Output Channel

Switch Setting

Visual Carrier

Frequency (MHz)

126

127

128

129

130

131

132

133

134

135

805.25

811.25

817.25

823.25

829.25

835.25

841.25

847.25

853.25

859.25

Frequency

Offset (kHz)

NONE

TABLE 2: T CHANNELS

CATV +100

CATV

BCTV

Channel Number

Visual Carrier

Frequency (MHz)

TABLE 3: BCTV CHANNELS

CATV +100

CATV

BCTV

Channel Number

Visual Carrier

Frequency (MHz)

T CHANNELS

55.25

61.25

67.25

77.25

83.25

175.25

181.25

187.25

193.25

199.25

205.25

211.25

7.00

13.00

19.00

25.00

31.00

37.00

43.00

49.00

Channel Number

Visual Carrier

Frequency (MHz)

645.25

651.25

657.25

663.25

669.25

675.25

681.25

687.25

693.25

699.25

585.25

591.25

597.25

603.25

609.25

615.25

621.25

627.25

633.25

639.25

525.25

531.25

537.25

543.25

549.25

555.25

561.25

567.25

573.25

579.25

471.25

477.25

483.24

489.25

495.25

501.25

507.25

513.25

519.25

705.25

711.25

717.25

723.25

729.25

735.25

741.25

747.25

753.25

759.25

765.25

771.25

777.25

783.25

789.25

795.25

801.25

7 SPECIFICATIONS

Frequency Range:

FCC Frequency Offsets:

Output level:

Output Impedance:

A/V Ratio:

Frequency Stability:

Intercarrier Frequency:

Spurious Outputs (5 MHz to 900 MHz):

In-channel C/N:

Broadband Noise:

7 to 864 MHz;

Standard CATV channels 2 to 135, IRC or HRC by moving an internal jumper. CATV T Channels, T7 - T14.

Broadcast TV channels 2 to 69.

Automatic (+12.5 kHz, +25 kHz, or none as required for each channel).

+45 dBmV (typical with 12 dB adjustment range).

75 Ohms, 12 dB return loss.

Audio carrier level, adjustable from -20 to -12 dB referenced to video carrier level.

±5 ppm.

4.5 MHz ±5 ppm.

-60 dBc typical, measured at -15 dB A/V ratio and with modulator output level of +45 dBmV.

65 dB typical, 4 MHz bandwidth.

-75 dBc typical, 4 MHz bandwidth @ +45 dBmV output.

VIDEO

Input Level for 87.5% Modulation:

Input Impedance:

Frequency Response:

C/L Delay:

Differential Gain:

Differential Phase:

Video S/N:

0.6 Vp-p to 1.5 Vp-p. Manual gain adjust with front panel control. Overmodulation indicator provided.

75 Ohms, return loss of 26 dB minimum.

20 Hz to 4.2 MHz, ±1 dB.

Within 50 nSec. of FCC Predistortion curve.

3% maximum (10 to 90% APL).

3 0 maximum (10 to 90% APL).

65 dB minimum, luminance weighted.

AUDIO

Input Level for 25 kHz Peak Deviation:

Input Impedance:

Pre-emphasis:

250 mVrms to 2.5 Vrms. Manual gain adjust with front panel control. Overmodulation indicator provided.

10 K Ohms, unbalanced.

Sec., defeatable by internal jumper for BTSC baseband stereo encoder compatibility.

Frequency Response

AG models:

AS Models:

Stereo Separation:

S/N ratio:

Total Harmonic Distortion:

40 Hz to 15 kHz, ±1.0 dB referenced to 75

Sec.

pre-emphasis curve.

40 Hz to 100 kHz, ±0.5 dB if pre-emphasis is defeated.

50 Hz to 14 kHz, ±1.0 dB referenced to 75

Sec.

pre-emphasis curve.

>30 dB, 100Hz to 10kHz, >20 dB, 50 Hz to 100 Hz,

>25 dB, 10 kHz to 14 kHz.

65 dB.

.5% maximum.

GENERAL

DC Power Input:

Supplied AC Adapter:

Operating Temperature:

Size:

Weight:

+10 to +18 VDC / 475 mA - from supplied AC adapter.

Input, 120 VAC / 60 Hz, wall adapter.

Output, 12 VDC / 800 mA maximum.

0 0 C to +50 0 C ambient.

8.25” (21 cm) W x 1.75” (4.45 cm) H x 7” (17.78 cm) D.

2 lbs. 6 oz. (1.08 Kg).

Specifications subject to change without notice or obligation.

8 WARRANTY

THREE YEAR LIMITED WARRANTY

R.L. DRAKE COMPANY warrants to the original purchaser this product shall be free from defects in material or workmanship for three (3) years from the date of original purchase.

During the warranty period the R.L. DRAKE COMPANY or an authorized Drake service facility will provide, free of charge, both parts and labor necessary to correct defects in material and workmanship. At its option, R.L. DRAKE COMPANY may replace a defective unit.

To obtain such warranty service, the original purchaser must:

(1) Retain invoice or original proof of purchase to establish the start of the warranty period.

(2) Notify the R.L. DRAKE COMPANY or the nearest authorized service facility, as soon as possible after discovery of a possible defect, of:

(a) the model and serial number,

(b) the identity of the seller and the approximate date of purchase; and

(c) A detailed description of the problem, including details on the electrical connection to associated equipment and the list of such equipment.

(3) Deliver the product to the R.L. DRAKE COMPANY or the nearest authorized service facility, or ship the same in its original container or equivalent, fully insured and shipping charges prepaid.

Correct maintenance, repair, and use are necessary to obtain proper performance from this product. Therefore carefully read the Instruction Manual. This warranty does not apply to any defect that R.L. DRAKE COMPANY determines is due to:

(1) Improper maintenance or repair, including the installation of parts or accessories that do not conform to the quality and specifications of the original parts.

(2) Misuse, abuse, neglect or improper installation.

(3) Accidental or intentional damage.

All implied warranties, if any, including warranties of merchantability and fitness for a particular purpose, terminate three

(3) years from the date of the original purchase.

The foregoing constitutes R.L. DRAKE COMPANY’S entire obligation with respect to this product, and the original purchaser shall have no other remedy and no claim for incidental or consequential damages, losses or expenses. Some states do not allow limitations on how long an implied warranty lasts or do not allow the exclusions or limitation of incidental or consequential damages, so the above limitation and exclusion may not apply to you.

This warranty gives you specific legal rights and you may also have other rights which vary from state to state. This warranty shall be construed under the laws of Ohio.

R.L. DRAKE COMPANY

230 INDUSTRIAL DRIVE

FRANKLIN, OHIO 45005 U.S.A.

CUSTOMER SERVICE AND PARTS TELEPHONE:

+1 (937) 746-6990

TELEFAX:

+1 (937) 806-1576

WORLD WIDE WEB SITE: http://www.rldrake.com

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