Service manual

All service and tuning procedures are performed
from the SERVICE menu, which is selected by press-
ing F2 from the MAIN MENU. Figure 2 illustrates how
the RSS alignment SERVICE screens are organized.
Figure 2. RSS Service Menu Layout
All SERVICE screens read and program the radio
codeplug directly; you do NOT have to use the RSS
GET/SAVE functions to use the SERVICE menus.
The SERVICE screens introduce the concept of
the “softpot,” an analog SOFTware controlled POTen-
tiometer used for adjusting all transceiver alignment
controls.
Each SERVICE screen provides the capability to
increase or decrease the ‘softpot’ value with the
keyboard UP/DOWN arrow keys respectively. A
graphical scale is displayed indicating the minimum,
maximum, and proposed value of the softpot, as
shown in Figure 3.
Figure 3. Softpot Concept
Adjusting the softpot value sends information to
the radio to increase (or decrease) a dc voltage in the
corresponding circuit. For example, pressing the UP
arrow key at the Reference Oscillator screen instructs
the radio’s microcomputer to increase the voltage
across a varactor in the reference oscillator, which
increases the frequency.
In ALL cases, the softpot value is just a relative
number corresponding to a digital-to-analog (D/A)
generated voltage in the radio.
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REFERENCE OSCILLATOR ALIGNMENT
TRANSMIT POWER ALIGNMENT
TRANSMITTER ALIGNMENT MENU
TRANSMIT DEVIATION BALANCE
(COMPENSATION) ALIGNMENT
TRANSMIT DEVIATION LIMIT ALIGNMENT
F2 -
F2 -
F3 -
F4 -
F5 -
RECEIVER ALIGNMENT MENU
F3 -
FRONT END BANDPASS FILTER ALIGNMENTF2 -
SERVICE
HELPF1 -
EXIT, RETURN TO SERVICE MENUF10 -
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CAUTION
Do NOT switch radios in the middle of any SER-
VICE procedure. Always use the EXIT key to
return to the MAIN menu screen before discon-
necting the radio. Improper exits from the
SERVICE screens may leave the radio in an
improperly configured state and result in seri-
ously degraded radio or system performance.
MAEPF 22858 O
Min.
Value
Max.
Value
015
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