Tx Deviation Balance (Compensation); Table 6-15. Transmit Current Limit Devices - Motorola ASTRO XTL 5000 Basic Service Manual

6-12
12. Left-click the Program All button to save tuned value.
13. Left-click the Close button to close screen and return to the Tuner Main Menu.
Band/Power Level
700–800 MHz 35 W/15 W Motorcycle
6.4.8

Tx Deviation Balance (Compensation)

NOTE: This alignment is required after replacing (or servicing) components on the transceiver board.
The Tx Deviation Balance (Compensation) alignment procedure balances the modulation
contributions of the low- and high-frequency portions of a baseband signal. Proper alignment is
critical to the operation of signaling schemes that have very low frequency components (for example,
DPL) and could result in distorted waveforms if improperly adjusted. This procedure needs to be
performed at multiple frequencies to allow for proper alignment across the entire RF band. The RF
band is divided into frequency zones with a calibration point (value) in each zone. When performing
this tuning procedure the PTT Tone Low generates an 80 Hz modulation frequency. The deviation
level of this 80 Hz tone is used as the reference level for adjusting the deviation level of the PTT
Tone High, which is a 3 kHz modulation frequency.
This test can be done with either the R-2670 Communication Analyzer or the Agilent 8901
Modulation Analyzer. The method of choice is the R-2670 Analyzer.
• Initial set up using the R-2670 Communication Analyzer:
- Connect a BNC cable between the "DEMOD OUT" port and the "VERT/SINAD DIST/DMM
COUNTER IN" port on the R-2670.
- Press the SPF key on the R-2670 to display the "SPECIAL FUNCTIONS MENU." Move the
cursor to "High Pass," and select 5 Hz on the soft key menu. Select 20 kHz for the "Low
Pass" setting.
- In the "RF Control" section of the R-2670, enter the frequency displayed on the Tuner
screen. Move the cursor to the "B/W" setting and select "WIDE
menu.
- Place the R-2670 cursor in the "Display" zone. Select "AC VOLTS" on the soft key menu.
Move the cursor to the "Range" setting and select "AUTO."
• Initial set up using the 8901 Modulation Analyzer:
- Press the FM MEASUREMENT button. (The "Error 03-input level too low" indication is
normal until an input signal is applied.)
- Simultaneously press the Peak - and Peak + buttons. Both LEDs on the buttons should
light.
- Press the 15 kHz LP filter key.
June 11, 2003

Table 6-15. Transmit Current Limit Devices

Final1
Radio Alignment Procedures: Transmitter Alignments
Devices
Final2
±
100 kHz" on the soft key
Driver
6881096C73-O