Programming; Alignment Procedure; Receiver; Transmitter - Maxon SD-125E Service Manual

The SD-125E Series radio requires the ACC-900E Programming Software, ACC-2125 Interface Cable, 9-15
VDC 200mA Power Supply. Refer to the ACC-900E Programming User's Manual for detailed information on
programming the SD-125E Series radio.
The SD-125E UHF/VHF Receiver is by design, broad band covering UHF(400-430 MHz & 440-470 MHz
&470-490 MHz) and VHF(148-174 MHz) and should require no special alignment, unless repairs are
performed on the receiver portion.
Should repairs be necessary, use the "Test Equipment Diagram" on
Diagram" on page 24, in conjunction with the following procedures:
• After just opening the upper cover, Power High/Low, Modulation level, Modulation balance and
Frequency can be directly controlled through holes at the digital PCB' s.

9.1 RECEIVER

1 Apply a standard test signal to the receiver antenna terminals.
2 Adjust RV403 for the specific audio output level.
RX VCO
1 Set the unit to the highest receive frequency 430MHz(UHF1), 470MHz(UHF2), 490MHz(UFH3),
174MHz(VHF) and verify the VCO control voltage is under 9.0 Volts. If it's over 9.0 Volts, adjust C308 of RX
VCO to 9.0 Volts
2 Set the unit to the lowest receive frequency 400MHz(UHF2), 440MHz(UHF2), 470MHz(UFH3),
148MHz(VHF) and verify that the VCO voltage is above 2.0 Volts. Adjust C308 to 2.0Volts.
• Note: Use TP1 to measure the voltage.

9.2 TRANSMITTER

Connect the unit to a Service Monitor with the power meter setting to the 10 W scale (or autorange)
TCXO
Set the channel selector to the mid-range frequency 460 MHz, adjust RV1 for a reading of 460 MHz ±200Hz
(155 MHz VHF models).
MAXONCIC
SD-125E RF LINK MODULE
page
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23& the "Alignment Points