Tools and test equipment required for setup are listed below. Equivalent items may be substituted. Ensure test equipment is calibrated and in good working order.

• Fluke Model 77 (or equivalent) true-rms digital voltmeter (DVM) with 0.001 resolution.

• Signal generator capable of generating carriers at 55.25 MHz and 1.2GHz

• “F” barrel adapter – 1.2 GHz

• Field strength meter capable of measuring up to 1.2GHz

• Field sweep receiver/transmitter with a minimum bandwidth of 1.2 GHz

• EXFO FOT 22AX optical power meter with adapters

• Fiber optic jumper to test transmitter optical output power

• Glendale Technologies optical eye protection blocking 900–1600 nm light

Perform the following steps to set up the forward path.

Note	The procedure uses an example with a transmitter modulation index of 2.5% per channel and the 1.2GHz node with RF output level of 54 dBmV @ 1218 MHz.

1. Ensure all unused RF ports are terminated with 75 ohms. Use an AC load if AC is routed to the RF port.

2. Open the housing according to Opening and Closing the Housing.

3. Carefully disconnect the forward path optical fiber(s), if connected.

   Warning

   Laser hazard. This product contains a class 3B laser with no safety interlocks. Under no circumstances should connectors be viewed with equipment enabled. Direct viewing of connectors can cause eye damage. Failure to adhere to this admonishment may result in serious injury to the eye(s) or even blindness.

   Caution

   Disconnecting the optical fibers of a working network element will interrupt customer service.

   Note	Ensure all optical connectors are clean. See Care and Cleaning of Optical Connectors.

4. Use an optical power meter to measure the level of the input light signal from the forward path optical fiber cable(s). Signal should be 0 dBm, 1mW, nominal. For a standard receiver, record the measurement(s).

5. Connect the forward path optical fiber(s) to the receiver. Use a DVM to measure DC voltage at receiver optical power level test point. Scale: 1V DC = 1mW (1310 nm transmitter) and 1.12 V DC = 1mW (1550 nm transmitter).

   

6. Set the receiver module attenuator switch as follows:

   	IF received optical power is...	THEN set the attenuator switch to...
   Standard Receiver	-2 to +2 dBm	-8 dB
   	-6 to -2 dBm	0 dB
   Low Input Receiver	-6 to -2 dBm	-8 dB
   	-10 to -6 dBm	0 dB

7. For standard input receiver, check the RF level at the -20 dB RF test point. Signal level should be +7 dBmV at the test point with 0 dBm optical input power and 2.5% index modulation of the laser headend transmitter. (With optical receiver attenuator set to the -8 dB switch setting.) This represents an optical receiver output of +27 dBmV.

   	For standard receiver	For low input receiver	Att/OMI
   Output level	27dBmV	27dBmV	8 dB/2.5%
   Input optical power	0dBm	-4dBm	8 dB/2.5%

8. The next step depends on your RF output levels.

   IF your RF output ports will...	and you have...	THEN...
   all have equal output levels	1X, or 2X segmentation	Go to step 9.
   be driven at different levels	1X or 2X segmentation	Go to step 10.

9. If all four of the node's output ports are to have equal output levels, re-balancing of the RF level should not be required for 4-way segmentation.

   To achieve an output level of 54 dBmV @1218MHz / 50.7 dBmV @ 1002 MHz

   • with 27 dbmV output from the optical receiver, install a 15 dB attenuator pad into the optical interface board just above the receiver module.

   Go to step 12.

10. If the node's output RF ports are to be driven at different levels, the port with the highest output level should be used to set up the node. Measure signal level at the forward RF test point, on the amplifier module, to identify the port with the highest level output signal. Verify the output power level is correct using the OIB Pad as in Step 9.

    Go to step 11.

11. Increase the attenuator pad value at the FWD PORT OUT PAD locations on the RF amplifier module to reduce the output level of the ports which need to be driven at a lower level than the port used to setup the node. See Technical Information for pad selection charts.

12. The GS7000 Node is set for 18 dB of linear tilt between 54 and 1218 MHz / 14.7 dB between 54 MHz and 1002 MHz.

    4-Way Forward Segmentable RF Amplifier Note: Four 18.0 dB linear field replaceable equalizers are installed in the node at the factory, one each on the four independent forward amplification paths. This achieves 18.0 dB of linear tilt between 54 MHz and 1218 MHz (14.7 dB between 54 MHz and 1002 MHz).

    If your network requires a different value, remove the field replaceable 18 dB equalizers and replace with equalizers of the appropriate value. See Forward Equalizer Chart.

13. If the RPD module is installed, make sure the correct FCM is used, and then plug an attenuator pad (value depends on the operator’s network) in OIB. When using the Analog Receiver for Overlay, the attenuator pad selected for the OIB will be 8 dB lesser value. Improved system performance is achieved by installing a combination Filter/Attenuator Pad, Cisco Part Number FLTRPD-RPD-55-xx.

14. Continue to Reverse Path Setup Procedure or close the housing according to Opening and Closing the Housing.

This procedure describes how to perform the reverse path setup. Perform this procedure only if your node has an active reverse path.

Perform the following steps to set up the proper level into the reverse path optical transmitters.

1. Open the housing according to Opening and Closing the Housing.

2. Verify the level of the input reverse RF signals at the RF test points located near the main ports of the RF amp module. Nominal level is +17 dBmV per channel. Install the appropriate value input pad at the REV PORT IN PAD location to attenuate the signal to the desired level for the reverse path of the node.

3. With the input to the node port set to 17 dBmV per channel, a 4 dB transmitter input attenuator pad should be installed on the optical interface board (just above the transmitter module) to achieve 13 dBmV level into the optical transmitter (-7 dBmV at the transmitter -20 dB test point). This RF input level into the high gain reverse transmitter will achieve an optical modulation index (OMI) of 10%.

4. Repeat steps 2 and 3 for each RF port carrying a reverse path signal.

5. Use an optical power meter to measure the transmitter optical output power. (1330 nm or 1550 nm)

   

6. Using a DVM, measure the DC voltage at the optical test point and record the value.

7. Check the connection of the optical connector. Make sure the optical connector is seated and verify that the fiber bend radius is greater than 1 inch.

   Warning

   When handling optical fibers always follow laser safety precautions.

8. If the RPD module is installed, make sure the correct RCM is used, and then plug an attenuator pad (value depends on the operator’s network) in OIB.

This section describes how to configure the forward signal routing of the node.

The receiver module/RPD and the forward configuration module determine the forward signal routing. Each module must be in its proper slot to achieve the different node configurations.

The following table shows the required modules for various node configurations.

Note	All pad values are approximate starting values.

This section describes how to configure the reverse signal routing of the node.

The transmitter modules and the reverse configuration module determine the reverse signal routing. Each module must be in its proper slot to achieve the different node configurations.

The following table shows the required modules and their slot locations for various node configurations.