Uhf Tuning Procedures; Figure 59: Preselector Tuning - Vhf; Preparing The Equipment For Uhf Alignment; Tuning The Uhf Preselector - Motorola ASTRO 25 GTR 8000 Manual

MN003286A01-E
Chapter 5: GTR 8000 Base Radio Optimization
Figure 59: Preselector Tuning — VHF
Procedure:
1 Turn the base radio power supply ON (to provide a 50 Ohm termination).
2 Adjust the signal generator to the frequency calculated in
Frequency For a Single Receive Frequency on page 160
Frequency for Multiple Receive Frequencies on page
3 Insert tuning probe into cavity H1 and adjust tuning screw 1 for a PEAK.
4 Leave tuning probe in cavity H1 and adjust tuning screw 2 for a DIP.
5 Insert tuning probe into cavity H2 and adjust tuning screw 3 for a DIP.
6 Insert tuning probe into cavity H3 and adjust tuning screw 4 for a DIP.
7 Insert tuning probe into cavity H4. Decrease output from the signal generator to –5 dBm.
8 Adjust tuning screw 5 for a DIP. Then turn tuning screw 5 an additional 1/4 turn
counterclockwise. (DIP is not as sharp for screw 5 as it was for screws 2 through 4.)
5.9.2

UHF Tuning Procedures

UHF tuning procedures include the following:
• Calculating Proper UHF Alignment Frequency on page 163
• Preparing the Equipment for UHF Alignment on page 164
• Tuning The UHF Preselector on page 164
162
Calculating The VHF Alignment
or Calculating The VHF Alignment
161. Set the level to +5 dBm.