Motorola MTR2000 T5544 Instruction / Field Service Manual page 321

1.
To Start
Remove cables from the duplexer, noting the position of each cable. Each cable is unique and must be returned to
the original position when tuning is complete.
2.
Tuning Low Pass Resonators
1.
Set up test equipment as
shown, connecting to cavity
#1.
2.
Push or pull tuning rod for
cavity #1 to obtain a PEAK
reading on the millivoltmeter.
3.
Use allen wrench and tighten
locking screw.
4.
Repeat steps 1 to 3 for
cavities #2 and #3.
Allen Locking
Screw
Resonator
Tuning Rod
3.
Tuning High Pass Resonators
1.
Set up test equipment as
shown.
2.
Push or pull tuning rod for
cavity #4 to obtain a PEAK
reading on the millivoltme-
ter.
3.
Use allen wrench and tight-
en locking screw.
4.
Repeat steps 1 to 3 for
cavities #5 and #6.
Allen Locking
Screw
Resonator
Tuning Rod
68P81085E16-B
09/30/05
Cavities
1 2 3
"T" Connector
6dB In-line
pad (50Ω)
Cavities
1 2
6dB In-line
pad (50Ω)
Figure 9. VHF Duplexer Field Tuning Procedure
4 5 6
3 4 5 6
"T" Connector
VHF Duplexer Module
Boonton 92E RF
Millivoltmeter
Range set to +10dBm
Loop Assemblies
HP8656B Signal Generator
Frequency set to Rx or Tx frequency,
whichever is LOWER.
Output Level set to +10dBm.
Boonton 92E RF
Millivoltmeter
Range set to +10dBm
Loop Assemblies
HP8656B Signal Generator
Frequency set to Rx or Tx frequency,
whichever is HIGHER.
Output Level set to +10dBm.
13