Olson Technology SA6940-RT - Manual (Page 4)

025-370548 REV X1 Page 4
INTRODUCTION
The Olson Technology Inc. SA6940-RT is a high quality, cost effective, Dual Return Transmitter module designed around the latest
optical transmitter technology. It is designed to operate and meet full specifications with an optical output level of 1 to 3mW. The
transmitter RF path includes a plug-in OMI pad which is preset at the factory for +7dBmV per carrier for 36MHz loading.
The SA6940-RT receives preconditioned 24V
DC
from the Node and plugs directly into the preexisting locations within the Node. The
primary RF connection is made through the built in connector on the bottom of the transmitter or the top of the transmitter by
changing a strap inside the transmitter for the 4x4 configuration. For models equipped with a secondary laser, an SMB connector is
located on the top of the transmitter. The transmitter can be ordered with an optical connection that will match the factory setup. Heat
transfer for the SA6940-RT is provided via the bottom surface of the module to the Node housing for full outdoor temperature
operation.
INSTALLATION / ENVIRONMENTAL CONSIDERATIONS
The SA6940-RT operates with an exterior temperature on the Node of -40 to + 60°C. However, like any other electronic device, it will
probably have a longer life span if it is not operated at the upper limit of it's temperature range continuously. Installation of the
SA6940-RT should be done such that water, dirt and other contaminates do not enter either the Node or the module. Do not install
equipment in locations that are accessible by either children or other unqualified personnel. This unit is meant to be field-installed
into the Scientific Atlanta 6940 Optical Node by qualified field service technicians.
To install the SA6940-RT, loosen the eight closure bolts on the Scientific Atlanta 6940 Node casting enough free them from the other
half of the housing. Open the housing and locate the plug in module section of the Node. Place the SA6940-RT module into one of
the two transmitter locations making sure the SA6940-RT module is in line with the mating connector in the Node.
NOTE: If replacing an existing transmitter, remove it and place the SA6940-RT in place of it (See Figure 1, next page).
Push the SA6940-RT into position firmly, seating the connector. Tighten the two captive screws firmly. Connect the incoming fiber
to the transmitter, then dress the fiber as to keep it clear of anything that may pinch or damage it.
NOTE: Be sure the fiber termination of the incoming fiber matches that of the transmitter, an easy way to tell is by the color of the
termination.
OPTICAL CONNECTORS AND CLEANING
The standard optical connector provided with the SA6940-RT is an SC/APC with an 8° angle. No tools are required for connection
to/from this type of optical connector.
The fiber ends can be damaged by the insertion of contaminated connectors into a bulkhead or receptacle, or by the insertion of a
clean connector into a dirty bulkhead. Fiber connectors should never be left uncovered. Optical connectors should be cleaned
before usage. Prepackaged alcohol wipes are the most convenient way to insure clean optical connectors. Fresh, clean alcohol and
lint free wipes or swabs may also be used.
EXTERNAL TEST POINTS
The SA6940-RT has one external test point for optical power output calibrated at 1V/mW. It should be monitored with a high
impedance voltmeter. This test point is for long term monitoring purposes. The optical output power should be measured using an
optical power meter at the time of installation.
If the transmitter is equipped with a 2nd laser to be used in a redundancy configuration, then the supplied splitter board must be
installed.