Preparing The Equipment For Vhf Alignment; Vhf Tuning Procedure - Motorola GTR 8000 Manual

GTR 8000 Base Radio
Procedure Steps
From the site documentation or the CSS, note the receive frequency for each channel supported by the base
1
radio/receiver.
2 Calculate a midpoint frequency as follows:
F = (F
mid highest
3 Using F
mid
Calculating The VHF Alignment Frequency For a Single Receive Frequency, page

5.8.1.2 Preparing The Equipment For VHF Alignment

Procedure Steps
1 Make sure the base radio/receiver (with preselector assembly) is installed in a functional station cage equipped
with a power supply module.
2 Detune the preselector as follows:
a. If the alignment frequency (calculated in
Receive Frequency, page 5-5
Frequencies, page
screws clockwise until 1/8" protrudes past each of the tension nuts.
b. If the alignment frequency is less than or equal to 148 MHz (Range 1) or 156 MHz (Range 2), turn the five
tuning screws counterclockwise until 3/4" protrudes past each of the tension nuts.
3 Using the torque driver and deep well socket, tighten the five tension nuts on the adjustment screws to 6 in-lbs.
4 See Figure

5.8.1.3 VHF Tuning Procedure

See Figure 5-1 for the location of the tuning screws and cavity probe holes.
When tuning for peak or dip, turn the tuning screw 1/2 turn past the peak or dip to verify that you have
obtained a true peak or dip. After ensuring you have found true peak or dip, turn the screw back to the
location of the original peak or dip.
5-6
+ F ) ÷ 2
lowest
in place of the base radio/receiver receive frequency, perform steps 3 and 4 from
or 5.8.1.1.2 Calculating The VHF Alignment Frequency for Multi Receive
5-5) is greater than 148 MHz (Range 1) or 156 MHz (Range 2), turn the five tuning
5-1.
5.8.1.1.1 Calculating The VHF Alignment Frequency For a Single
5.8.1.1.1
5-5.
6871022P86-A - November 2012