Maxon SD-125EL Quick Start Manual

MAXON
SD-125 RF LINK MODULE

PROGRAMMING

The SD-125 Series radio requires the ACC-900 Programming
Software, ACC-2000 Interface Module, 9-15 VDC 200mA
Power Supply and QPA-4000 Programmer Interface Cable.
Refer to the ACC-900 Programming Manual (P/N:
680-110-0032) for detailed information on programming the
SD-125 Series radio.

ALIGNMENT PROCEDURE

The SD-125 UHF/VHF Receiver is by design, broad band
covering UHF(400-430 MHz & 440-470 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 page 17 & the "Alignment Points Diagram" on
page 18, in conjunction with the following procedures:
•
An Extender Board (P/N: 650-060-0016) is required
in order to separate the Digital and RF PCB's to
allow access to the alignment points. Installation
instructions are provided with the Extender Board
Assembly.

RECEIVER

1. Apply a standard test signal to the receiver antenna
terminals.
2. Adjust T1 for maximum sensitivity and audio
output with minimum audio distortion.
3. Adjust RV403 for the specific audio output level.

RX VCO

1. Set the unit to the highest receive frequency,
470MHz(UHF), 174MHz(VHF) and adjust the
VCO L303 to 8 volts.
2. Set the unit to the lowest receive frequency
440MHz(UHF), 148(VHF) and check that the VCO
voltage is above 2.0 volts. If voltage is below 2.0
volts, adjust L303 for 2.0 volts or more.
•
Note: Use TP1 to measure the voltage.

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 TCX01 for a reading of 460 MHz ±200Hz (155 MHz
VHF models).
PAGE-14-
October 98