Yaesu FT-902DM, Instruction Manual

Page: 19 / 55

on . the rear panel. The FT-9 02DM is se t up for
1 7 0 Hz shift , and the shift frequency may be ad­
justed some what by means of the trimmer capaci­
tors located under the top cover. The CARR c on­
trol must b e adjusted in the TUNE p osition for
not more than 1 00 niA . Ex cessive cathode current
may result in damage to the final amplifier tubes.
Audio output from the transceiver may be taken
from the SP j ack in the rear apron.
FM OPERATION
Note : The FM Unit is built-in on the FT-902D/
DM, and is an available accessory on the
FT-9 02D/DE m o dels.
After completing the basic transmitter tune-up ,
set the CARR c ontrol for 1 00 mA carrier level
in
the FM mod e . Speak into the microphone in
a norm al voice. The MIC GAIN and PROC LEVEL
controls have no effect in the FM mode .
For FM reception, the SQL control on the front
panel should be advanced only as far as required
to silence b ackground noise. When adjusted just
past the silencing threshold , the squelch circuitry
will provide noise-free recep tion with maximum
sensitivity to weak FM sign als.
In areas of very high occupancy, where channels
are crowded , an additional FM crystal filter is an
available option.
DIAL CALIBRATION AN D FREQUENCY
DETERMINATION
The FT-902DM mixing scheme accounts for the
difference in carrier frequencies between USB and
LSB. For this reason , no recalibrat ion is require d .
Once the calibration is properly aligned (at the
factory , or in shop ) , n o further adj ustment is
required for accurate frequen cy derivation . The
2 5 kHz or 1 00 kHz calibrator is included largely
for alignm ent purposes, as it p rovides a useful
re ference signal for signal peaking, et c.
Frequency reado ut on the FT-9 02DM digital
display is straightforward . The full operating
frequency is displayed , with resolution to 1 00 Hz.
The analog display on the transceivers provides
easy determination of the operating frequency .
The frequen cy disp l ayed o n the analog sub dial
is added to the lower band edge frequency .
For example , if .the analog dial indicates 074, a s
shown i n t h e e x ampl e , and t h e BAN D swit ch is on
40 meters (lower band edge : 7000 kHz ) , the
operating frequency will b e 7074 kHz. By rot at ing
the BAND swit ch , this position of t h e analog
display will p ro du ce 1 4074 kHz for 20 m eters,
2 1 074 for 1 5 meters, etc. For 80 and 1 2 m eters, the
lower band edges are 3 5 00 kHz and 2 4 5 00 k H z,
while for 1 60 m eters the band edge is 1 . 5 MHz.
There fore , the dial should read 074 t o produce
3"5 74 kHz , b ut 3 74 for l 874 kHz. Be careful so a s
not to operate outside the amateur bands.
SELECT SWITCHES/ME MORY SYSTEM
OPERATION
(Note : The memory unit is built-in on the DM
model, op tional on the D/S D/DE models)
Frequency control o f the FT-9 02DM is b y means
of the intern al VFO, the memory uni t , an e x­
ternal VFO, or various combinations of the three.
--17-