Cavity Combiner; Cavity Combiner - Theory Of Operation; Figure 7-24 Auto Tune Cavity Combiner - Motorola DIMETRA MTS 2 Installation, Configuration And Basic Service Manual

MTS 2 and MTS 4 Installation, Configuration and Basic Service Manual

Cavity Combiner

There are two types of Cavity Combiners available:
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•
MTCCs are functionally the same as ATCCs except that they are tuned manually instead of electronically.
Minimum channel spacing of the TX channels is 150 kHz while the recommended channel spacing is 250 kHz.

Figure 7-24 Auto Tune Cavity Combiner

Cavity Combiner - Theory of Operation

A minimum of 2 watts is needed at a cavity input. The ATCC will automatically tune in 40
seconds maximum. For more detail, refer to the ATCC specification.
Once an RF signal greater than 2 watts is detected, the ATCC tunes the cavity and continuously
keeps it tuned over humidity, temperature and changing transmit frequency, so long as it
does not sense one of the following alarm conditions:
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•
•
Being tuned means that a cavity is within the insertion loss specification at the frequency of the applied
PI/4DQPSK or QAM4,16,64 signal that is within the average input power range specified above. Being tuned
also means that the cavity peak response is no greater than 25 kHz away from the TX carrier centre frequency.
6802800U74-N September 2009
Auto Tune Cavity Combiners (ATCC)
Manual Tune Cavity Combiners (MTCC)
MTS 2 does not support Cavity Combiners.
Channel Spacing alarm
VSWR alarm
Failure to Tune alarm
Cavity Combiner
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