
Series 3000
Model R-159A
SYNC SENSOR SWITCH
INSTRUCTION MANUAL
Monroe Electronics
100 Housel Ave ⏐ Lyndonville ⏐ NY ⏐14098
800-821-6001 ⏐ 585-765-2254 ⏐ fax 585-765-9330
monroe-electronics.com
Printed in USA ⏐ Copyright© ⏐ Monroe Electronics, Inc.
Specifications subject to change without notice
P/N 1340172
010807

TABLE OF CONTENTS
WARRANTY/ RETURN POLICY PAGE 3
SPECIFICATIONS PAGE 4
GENERAL DESCRIPTION PAGE 5
INSTALLATION PAGE 6
Accessories included:
3000R-159A Manual
3000R/22M Rack Mounting Kit
Wall mount power supply
2

WARRANTY
Monroe Electronics, Inc. warrants to the owners, each instrument and sub-assembly
manufactured by them to be free from defects in material and workmanship for a period
of one year after shipment from factory. This warranty is applicable to the original
purchaser only.
Liability under this warranty is limited to service, adjustment or replacement of defective
parts (other than fuses or batteries) on any instrument or sub-assembly returned to the
factory for this purpose, transportation charges prepaid.
This warranty does not apply to instruments or sub-assemblies subjected to abuse,
abnormal operating conditions, or unauthorized repair or modification.
Since Monroe Electronics, Inc. has no control over conditions of use, no warranty is
made, or implied as to the suitability of our product for the customer's intended use.
THE WARRANTY SET FORTH IN THIS ARTICLE IS EXCLUSIVE AND IN LIEU OF ALL
OTHER WARRANTIES AND REPRESENTATIONS, EXPRESS, IMPLIED OR
STATUTORY INCLUDING, BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. Except for obligations expressly undertaken by
Monroe Electronics, in this warranty, Owner hereby waives and releases all rights,
claims and remedies with respect to any and all warranties, express, implied or statutory
(including without limitation, the implied warranties of merchant ability and fitness), and
including but without being limited to any obligation of Monroe Electronics with respect to
incidental or consequential damages, or damages for loss of use. No agreement or
understanding varying or extending the warranty will be binding upon Monroe
Electronics unless in writing signed by a duly authorized representative of Monroe
Electronics.
In the event of a breach of the foregoing warranty, the liability of Monroe Electronics
shall be limited to repairing or replacing the non-conforming goods and/or defective
work, and in accordance with the foregoing, Monroe Electronics shall not be liable for
any other damages, either direct or consequential.
RETURN POLICY TO FACTORY:
Materials returned to Monroe must have a Return Material Authorization number. To
obtain a RMA number, contact our A/V Switching & Control Customer Service at 585765-2254 or fax 585-765-9330. Customers have 30 days to determine that the product
ordered fills their need and performs as described in Monroe’s literature. Units returned
for approved repair or credit, must be in the original packaging including all parts and
paperwork plus be in very good physical condition. If not, the customer is billed the cost
to refurbish the unit and for missing accessories and merchandise. No products may be
returned for exchange or credit after 12 months of the shipment date. Monroe reserves
the right to repair or replace units under warranty.
3

Specifications
Video Input Level:
0 dBmV +3dBmV
Composite Audio Input Level:
0 dBmV +3dBmV
Video Output:
Unity gain, 2 buffered outputs
Audio Output:
Unity gain, 2 buffered outputs
Power Requirement for External Power Supply:
Input: 120 VAC 60 Hz (240 VAC available)
Output: 9V AC 1.9A
Physical:
19” W x 3.5” H x 4” D
Weight: 4 lbs.
4

General Description
Monroe Model R159A Sync Sensor Video Backup Switch monitors composite baseband video
sync from a single channel, for 3 separate channels. It outputs each baseband video signal and
its accompanying composite audio, to two separate output connectors.
When baseband video loses sync or its level decreases by more than 3 dBmV, the R159A
switches to a secondary baseband input with composite audio. When the original signal
returns, it switches back to the original signal pair.
At the same time, the switch change activates a remote indicator solid-state switch on the back
panel, for status monitoring systems, as well as an LED on the front panel, for local
troubleshooting.
Each switch section can be overridden by an external contact closure to ground.
5

INSTALLATION
MOUNTING:
The R159A requires a minimum of 3.5 vertical inches of space in a standard 19-inch wide EIA
equipment rack. Slide the unit into the rack frame and secure it, using the 3000R/22M mounting
hardware supplied with the unit.
CONNECTIONS:
For each of the three sections, the primary video is connected to the primary video F connector
and the secondary video to the secondary video F connector. Make sure the video at the
primary input is 0 +3 dBmV, and that the secondary input is 0 +3 dBmV. The two output F
connectors may be connected to whatever input the user desires. If one of the outputs is not
used attach a 75Ω terminator to that F connector.
For each of the three sections, the primary composite audio is connected to the primary 4.5
MHz F connector and the secondary composite audio is connected to the secondary 4.5 MHz F
connector. The outputs from the 4.5MHz switch are connected to the desired inputs. If one of
the outputs is not used attach a 75Ω terminator to that F connector.
OPERATION:
Whenever the video signal on the primary video connector drops below –3 dBmV the video
output is switched to the secondary input. At the same time, the composite audio input is
switched to the secondary input. When the switch occurs, a solid-state contact closure to
ground occurs at the alarm output connector pin and the red LED on the front panel illuminates.
When in alarm condition, the operator may force the switch back to primary inputs by closing the
test switch input on the connector to ground. This enables the operator to check the status of
the primary inputs manually.
POWER:
The R159A requires 9 VAC. Attach the power pack’s wires to the appropriate screw terminals
on the back of the R159A and plug it into a 120 VAC outlet.
6