Olson Technology T-6940 User Manual

FRMUC/T-6940

FREQUENCY MULTIPLIER UP CONVERTER WITH RETURN LASER

TRANSMITTER FOR SA-6940 NODE

INSTRUCTION MANUAL

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025-000440 REV A 1/23/02

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TABLE OF CONTENTS

INST ALLA TION GUIDE Page 3

OPERA TIONAL SETUP

1. Operational setup for RF Page 6

2. Operational setup for Transmitter Page 7

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Page 2

INST ALLA TION INTO SCIENTIFIC-A TLANT A 6940 NODE

Install the converter/transmitter in the 6940 node per the instructions located on page 4.
Use caution in handling the SMB connectors on the RF cables used with the converter and the node. Always
remove them by pulling them straight out. Try to pull on the connector , not the cable. Always install them by
pushing them straight in.
If this installation is being done on an operating node, CONNECT THE FIBER TO THE TRANSMITTER
BEFORE PLUGGING-IN THE DC POWER CABLE FROM THE CONVER TER/TRANSMITTER.
If this installation is being done on a non-operating node, CONNECT THE FIBER TO THE
TRANSMITTER BEFORE APPL YING POWER T O THE NODE WHEN THE NODE IS INST ALLED.

DANGER- -LASER RADIA TION- -DANGER

THIS UNIT EMITS INVISIBLE LASER RADIA TION FROM THE LASER TRANSMITTER THA T

CAN CAUSE PERMANENT EYE DAMAGE

AVOID DIRECT EXPOSURE TO BEAM

APPL Y DC POWER AND OPERATE ONLY WITH PROPER OPTICAL FIBER INST ALLED IN

TRANSMITTER CONNECTOR

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Page 3

For demonstration purposes a base configuration SA-6940 is being shown. Other configurations may
exist.

NOTE: The OT FRMUC/T-6940 unit uses 75

Ω Ω

Ω type SMB connections on the RF cables. These connec-

Ω Ω

tions (and those they mate with) can be damaged if inadvertantly abused. Use caution in handling and
plugging/unplugging these. Always press them straight in and pull them straight out.

NOTE: The upconverter/laser transmitter has thermally conductive material applied to its mounting
surface. This material is an important part of the thermal management design. It must be present as
originally installed. This material is somewhat soft and can be damaged by abuse or mishandling. Be sure
that no debris gets between the thermally conductive material and the surface it mounts-to.

Step 1: Remove all cables necessary to remove cover plate from SA-6940. (See Figure 1)

Figure 1:

Step 2: Remove the cover plate.
Step 3: Remove the Feeder Return Combiner from PDD2 (See Figure 2). Y ou may then install the Olson Port
Interface Board (40-000620), which is supplied with this kit, at PDD2 (See Figure 3)

Figure 2: Figure 3:

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Page 4

Step 4: Install the upconverter/laser transmitter using its captive screws. Route the R.F . cables down between the
FRMUC and the fiber management tray as shown. (See Figure 4) NOTE: Use Caution so the screwdriver does
not damage the band 4 cable connection as the hinge-side screw is started and tightened. T ighten the mounting
screws firmly

Step 5: Feed the RF cables through the cover plate and then connect them as shown in Figure 5. The cables are
marked on each end to show where they connect. (Example: A cable marked with B1 and P3, will connect to band
1 on the upconverter, and port 3 on the port interface board.)

Figure 4: Figure 5:

Step 6: Install the cover plate into its original position, making sure the RF cables go out through the cutout. Arrange
the cables so they are not pinched between the cover and the feeder forward splitter at PDD1. Tighten the cover
screws.

Step 7: Re-connect the node DC power cable to PWR-2 and the RF cables to their proper connectors as shown in
Figure 6.

Step 8: Connect the FRMUC DC power cable to the DC power connector J11 located under the fiber manage­ment tray . Route the cable along the dotted line shown in Figure 7. Arrange it under the aluminum ear and AC cable
to hold it down in place.

Figure 6: Figure 7:

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NOTE:

If this installation is being done on an operating node, CONNECT THE FIBER TO THE TRANSMITTER
BEFORE PLUGGING-IN THE DC POWER CABLE FROM THE CONVER TER/TRANSMITTER.
If this installation is being done on a non-operating node, CONNECT THE FIBER TO THE TRANSMITTER
BEFORE APPLYING POWER TO THE NODE WHEN THE NODE IS INST ALLED.

DANGER--LASER RADIATION--DANGER

THIS UNIT EMITS INVISIBLE LASER RADIA TION FROM THE LASER TRANSMITTER THA T

CAN CAUSE PERMANENT EYE DAMAGE

AV OID DIRECT EXPOSURE T O BEAM

APPLY AC POWER AND OPERA TE ONL Y WITH PROPER OPTICAL FIBER INSTALLED IN

TRANSMITTER CONNECTOR.

Step 9: Carefully check cable flexing and fit by closing the housing several times. Arrange cables as necessary to
ensure there are no problems.

OPERATIONAL SETUP - RF

The converter accepts four separate return inputs, one from each feeder leg. It up-converts three of them to
three different bands, and combines them with one un-converted band. This combination of four bands plus a
pilot carrier at 4.5MHz is fed into the laser transmitter for return transmission via fiber .
If the FRMUC/T -6940 is installed properly , the frequencies of the four bands and their relationship to the four
feeder legs are as follows:

FEEDER POR T THREE BAND ONE 5MHz to 42MHz
FEEDER PORT FOUR BAND TWO 51.5MHz to 88.5MHz
FEEDER PORT FIVE BAND THREE 121.5MHz to 158.5MHz
FEEDER POR T SIX BAND FOUR 169.5MHz to 206.5MHz

The return carrier levels from each feeder leg into the converter should be checked and adjusted if necessary .
The levels from the four feeders can be checked at R TP3 through RTP6 and the levels can be padded with
RP AD3 through RP AD6 in the SA main RF chassis if necessary .
The specification for MAXIMUM carrier level into each converter band is defined as +15dBmV per (CW)
carrier with six carriers present. For best return optical system performance, the input level should be a MINI­MUM of +12dBmV per (CW) carrier with six carriers present. The carrier levels may be adjusted as necessary
to provide channel-loading equivalent to the six-carrier levels.
Remember to factor-in the test point value when making carrier level measurement at the test points. The levels
mentioned above are ACTUAL levels at the feeder legs/converter inputs.

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OPERA TIONAL SETUP - TRANSMITTER

The DFB Laser T ransmitter included with the FRMUC/T -6940 has been adjusted at the factory for the proper
optical modulation index provided the RF levels are in the range mentioned above. No further adjustment to the
transmitter is required.
The optical power of the Laser Transmitter has been set at the factory at 3mW. No further adjustment to the
transmitter is required. If the optical power is measured and found to be much less than 3mW , optical connector
cleaning may be required.
The Laser Transmitter has two DC test points. One is for laser current and is scaled at lV per 50mA. The other
is for optical output power at the laser and is scaled at 1V per mW . It recommended that these two test points
be measured (with a DMM) and that their readings be retained as historical data.

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