Terrasat Rx 1+1, Operation Manual

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Troubleshooting
1. Ensure that the 15 VDC to 24 VDC (LNB Bias) is present at the modem Rx input
(or IFU Rx input) by using a DVM. If it is not, check the cable and modem.
2. Use a spectrum analyzer to ensure that the 10 MHz signal is present at the modem
Rx input (or IFU Rx input). If it is not, check the cable and modem.
3. Connect the LNB to the demodulator (or IFU) by attaching the coaxial cables from
the Rx L-band output on the LNB to the demodulator (or IFU) Rx L-band input
port. If the Rx level is low, check the cable, feedhorn, and antenna for proper
operation.
Power Supply Checks
Before beginning RF troubleshooting, verify that the proper voltage is being supplied
to the Rx 1+1 system. Input DC voltage and current consumption data are available
using any of the M&C interfaces. Verify that the values are within limits.
If M&C is not available, use a multimeter to verify that the appropriate voltage
(24 VDC or 48 VDC are present. Check the part number label of the Rx 1+1 system to
determine the required voltage.
AC Power Problems/Conditioning
In today’s electrical environment, there are many types of power-related problems that
can prevent proper operation of sensitive electronic equipment. These noise problems
or disturbances can caused by such things as voltage induced by lightning, switching
high-power electrical equipment On/Off, or utility company actions such as power
factor correction. Serious problems can arise with the occurrence of transients and
spikes which can cause random errors or even failure of the circuitry.
Whatever the origin of the transients, they can be classified into two simple categories:
• Common mode
Noise voltage that appears equally and in phase from each signal conductor to
ground.
• Normal mode (also known as differential mode)
Noise potential between the power line conductors. It adds to and subtracts from
the power line sinusoidal wave.
WARNING
DC power will be present on the cable.
Terrasat recommends the use of a DC
block.