Receiver; Interstage Transformers; S-Meter Calibration; Scanner Center Stop - Yaesu FT-2500M Technical Supplement

Alignmen

Receiver

Set up the test equipment as shown below for
receiver alignment.
Receiver Alignment Setup
R F Signal
Generator

Interstage Transformers

0
Connect the DC voltmeter between J1 003 pin
7 and chassis ground.
0
Modulate the RF signal generator with ±3.5
kHz deviation of a 1-kHz tone.
0
Adjust T1 001 - T1 004,
Unit for maximum voltage on the meter, then
once again for optimum SINAD (at least -7
dBµ for 12 dB SINAD).
T 1 00 1
T 1 002
T 1 003
T 1 004
T 1 006
J 1 003 Pin?
VR 1 00 1
2-8
4
Speaker or -ohm
lead. resistor
AF Millivoltmeter
Regulated
13.BV PSU
S I N A D Meter
Distortion
Meter
&
T1 006 on the Main
Receiver Alignment Points

S-Meter Calibration

0
While tuned to 1 46.000 MHz, inject a +25 dBµ
RF signal modulated with ±3.5 kHz deviation
of a 1-kHz tone, and adjust VR2 006 on the
CNTL Unit so that all S-meter segments are
just on.

Scanner Center Stop

0
Connect the DC voltmeter (3-V range) be­
tween TP2002 ( +) and TP2001 (-) on the CNTL
Unit.
0
With both the transceiver and signal generator
tune to 1 46.000 MHz, set the SOL control fully
counter-clockwise (the
should be on). Inject 20 dBµ RF modulated
with ±3.5 kHz deviation of a 1-kHz tone, and
adjust VR2007 on the CNTL Unit for 0 V on the
voltmeter.

Squelch

0 SQL
Preset the control to the 1 0 o'clock posi­
tion. At the center of the band, tune the
signal generator to the same frequency, and set
the generator level to -12 dBµ .
0
Tum VR1 001 clockwise until the squelch just
closes, and then counter-clockwise very
slightly so that it just opens.
FT-2500M Technical Supplement
indicator
" BUSY "
RF
VR2007
T P200 1 ( - )
T P2002 ( + )
VR2006