Motorola MTX Series Service Manual page 64

C. Secure TX Deviation
Transmit deviation balance compensation and
transmit deviation limit adjustments should be complet-
ed before secure deviation is adjusted. Remember to
use the new transmit deviation balance procedure out-
lined in paragraph B before performing the following
steps.
1. From the SERVICE menu, press F2 to select
TRANSMITTER alignment.
2. Press F8 to select the SECURE TX DEV softpot.
3. Press F6 to key the radio on the test frequency.
The screen will indicate that the radio is transmit-
ting.
4. Measure the secure deviation on your service mon-
itor.
5. Use the up/down arrow keys to adjust the secure
deviation per Table 2.
Table 2. Secure Deviation
Channel Spacing (KHz)
25 / 30
20 (VHF/UHF)
20 (821-824, 866-869)
12.5
Secure Deviation (KHz)
2.91 - 3.06
1.69 - 1.84
1.69 - 1.84
N/A
6. Press F6 to dekey the radio. Press F8 to program
the softpot value.
7. Press F10 to return to the TRANSMITTER menu.
D. Secure RX Discriminator Level
1. Set the RTX4005B Test Box meter selector switch
to the "MX DISC" position, and connect an ac volt-
meter (capable of 1mV resolution on a 2V scale) to
the test box AC/DC meter port.
2. From the SERVICE menu, press F3 to select
RECEIVER alignment.
3. Press F8 to select the SECURE DISCRIMINATOR
LEVEL softpot. The screen will indicate the receive
test frequency to be used.
4. Set the RF test generator to the receive test fre-
quency. Set the RF level at the radio standard
antenna port to 1mV (-47dBm) modulated with 3.0
kHz FM deviation of a 1 kHz tone.
5. Use the UP/DOWN arrow keys to obtain a discrimi-
nator level between 206 - 218mVrms (target value
of 212 mVrms) observed on the ac volt-meter.
6. Press F8 to program the softpot value.
7. Press F10 to return to the RECEIVER menu.
55