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Bandwidth too low Coaxial plant capacity is higher than AML capacity and AML bandwidth needs to be expanded. 1.Upgrade receiver, and  

2.Upgrade broadband transmitters; or  

3.Add channels to channelized transmitter, or  

4.Add broadband transmitter to channelized transmitter. 

 1.Refurbished MTX-132 channel module or MTX-132 bay.  

2. Refurbished STX-141 transmitter or STX-141 transmitter bay.  

3.Broadband solid state source
Receiver phase noise  Phase noise problems discovered.  Replace the source and/or VCXO. SSS replacement kits (with DRO)
Multipath effect Some channels at some receive sites are lower in power or have excessive ripple. Realign antennas (transmit and receive) to eliminate the multipath effect, check for path design (reflections).  
Low receive signal Channels at some receive sites are too low (low CNR). Check for path design, check all connectors at receive sites, check LNA (if used). Replace faulty units.
Receiver caused OOB carrier problems C group pilot filters in some receivers are too wide. Replace or remove C group pilot filters (adjust the pilot level down and AGC circuitry at all receive sits address individual complaints about the beat on channel 5 by installing pilot traps on individual drops). New PT trap (very narrow)
Broadband Transmitter Phase Noise Phase noise problems are discovered in all receive sites on all channels. Replace the source and possibly the XO in the transmitter. SSS replacement kits (with DRO) and XO upgrade kit.
Low Power 
transmitter phase noise 		 Phase noise problems are discovered in all receive sites on all channels fed from the same source. Replace the shared source in the transmitter. SSS replacement kit (with DRO)
Low power channelized 
transmitter phase noise problems		 Phase noise problems are discovered in all receive sites on all channels. Replace the XO in the transmitter. XO conversion kit
High power channelized transmitter phase noise Phase noise problems are discovered in all receive sites on some channels.. Replace the sources in transmitters with impaired channels. SSS replacement kit (with DRO)
High power channelized transmitter phase noise Phase noise problems are discovered in all receive sites on all channels. Replace the XO in the transmitter. XO conversion kit
Broadband transmitter level; too low Low levels are measured on all channels at one, few, or all receive sites. Inspect all the connections from RF inputs to antenna inputs.  
Channelized transmitter level; too low  Low levels measured on few or all channels at few, or all receive sites. Inspect all the connections from RF inputs to antenna inputs.  
Frequency response/group delay inequality Excessive frequency response problems at all receive sites on one or few channels. Retune upconverter channel filters and output filter (if exists), replace them if realignment is not successful; retune klystron amplifier. 

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 Replacement filter kits.
Overdriven channelized transmitter Digital signals (test signals or digital TV signals) show high BER or blocking for no apparent reason, linearity test discovered problems. Realign the RF level to the transmitter (upconverter). If the level cannot be adjusted to the required level, replace the old klystron with a new one or with SSPA. SSPA (Retrofit kits) or Klystrons.
High power channelized transmitter OOB carrier problems OOB carrier and other carriers in the pilot transmitter interfere with each other and impair the OOB signal or other services. Retune the pilot transmitter and adjust all RF levels to the values recommended. If the realignment does not help, replace the aged klystron with a new one or with SSPA. SSPA (Retrofit kits) or Klystrons.
Low power channelized transmitter OOB carrier problems OOB carrier and other carriers in the pilot transmitter interfere with each other and impair the OOB signal or other services. Retune the pilot transmitter and adjust all RF levels to the value recommended. If the realignment does not help, add another upconverter to carry OOB carrier.  

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