Users Manual Part 1
recommended setting of the fine tune timer, if the MTS 4 is installed in a controlled environment, is 480
Minutes. For sites where the MTS 4 is exposed to more than +/- 20% variation in RH, the
recommended setting of the fine tune timer is 60-200 minutes depending on the speed of the variation.
Having a second cavity tune up and pass through the desired channel, the desired channels insertion
loss dips no more than 3 dB more than the max insertion spec for a period of 0.25 seconds. The cavity
tuning rate should be faster than 1 MHz per second.
The following list contains control and monitoring features available through the CAN Bus:
• Request current tuned position/frequency of a specific cavity.
• Fine tune time feature, to re-tune each cavity with a specified interval.
• Park an individual cavity, but if RF power is still present, cavity will park and then retune again.
•
Input power: request current measured input reflected power of a specific cavity.
• VSWR: request input VSWR of an individual cavity.
• Tuning status of each cavity; parked, tuning, tuned, and parking.
• Alarm conditions of each cavity are reported when requested, including : VSWR, subband, channel
spacing and failure to tune.
7.3.6.2
Replacing the Cavity Combiner
Process:
1 Remove the Cavity Combiner.
See Removing the Cavity Combiner on page 306.
2 Reinstall the Cavity Combiner.
See Reinstalling the Cavity Combiner on page 307.
7.3.6.2.1
Removing the Cavity Combiner
Procedure:
1
WARNING: RF energy hazard and potential equipment damage precaution.
To prevent accidental contact with high energy and injury to personnel, switch off the Power
Supply Unit.
2 Remove the door of the cabinet completely.
3 Remove the three screws fastening the Cavity Combiner to the brackets of the cabinet.
Two screws are on the left and one is on the right side of the Cavity Combiner.
4 Remove all TX and signal cables.
5 CAUTION: The Cavity Combiner can weigh up to 11.8 kg (26 lbs.). Use caution when
removing or installing Cavity Combiner into the equipment rack. To avoid injury to
personnel and equipment damage, ensure that the combiner is fully supported when free
from mounting rails.
Slide out the Cavity Combiner.
6802800U74-AP
Chapter 7: Radio Frequency Distribution System
306