Yaesu FT-902DM, Инструкция по эксплуатации

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(8) PRESELECT
Th is contro l pret unes the signal circuits for both
transm i t and receive. The PRESE LECT circuit
provides
c ontin uo us pe rm eability tuning through­
ou t the f reque n cy r ange of the tr ansceiver.
(9)
BAND
The BAND
s
w
i
tc
h
p rovides sele ction of the band
desired, 160
thr ough
I 0
me ter s.
(I 0)
RF GAIN/CLARIFIER
The RF
GAIN and CLA RIFIER control s are
m ount ed on con cen tric shafts. The RF GAIN
control provides
manual con trol of the gain levels
of the
RF and IF amplifiers on receive.
The
CLARIFIE R con trol allows man ual offse t of
±2.5 kHz
of either t he transmit or receive fre­
quency.
S elec tion of transmi t or receive clarifier
is
made hy
the t wo s ilver pushbu ttons t o the
left
of
th e C LA RIFIER con trol .
(ll)ATT
The ATT (RF
atten uator) button p rovides inser­
tion
of
a
20 dB
a t te nuator i n the incoming signal
p:i th t o
minimize
receiver cr oss modulation cau sed
b y ext reme ly str ong l ocal signals.
( 1
2) PROC
LEVEL/
AF GAIN
The
PROC LEVEL and AF GAIN con trols are
mounted
o n concen tric shafts. The P ROC LEVEL
c ontro l allow s manu al c on tr ol of the outpu t l evel
of
t he
RF
sp eech p roces sor. The processor is
actuatPd by
p res sing the silver p u shbu tton to the
le ft of the P'ROC LEVEL con trol .
The
AF
GA
I
N
con trol adjusts the audio outp u t
l eve l a t t he speake r and phone jack. Clockwise
rot£1 tin n i ncre ase s the a udio outp ut.
(13)TUNE
This
pu shbu tton , when depressed , places the trans­
m itte r in the " tune" condi tion for ten seconds
f or tuni ng p ur poses. After ten secon ds , the trans­
ce ive r is re turned to the receive mode so as t o
pr even t damage to the fina l amplifier tubes c ause d
b y excessive " key down" time during tune-up .
( 1 4) LOADING
T his cont rol tu nes the outp u t circuit of th e pi net­
work to match the an tenna/feedline imp ed ance .
( 1 5 ) PLATE
This con trol tunes the plate circuit o f the final
amplifier.
( 1 6) DTh1
This control allows dimming of the me ter and dial
lamp s.
( 1 7) CARR/ KEYER
The CARR and KEYER con trols are m ounted
o n c on centric shafts. The CARR con trol vari es
the a mount of carrier in the CW , AM ,
FSK,
and
FM models of op eration.
The KEYER control varies the sp e e d of t he
built- in Curtis 8044 IC electronic keyer.
(1 8) VOX GAIN
This con trol selects MOX/PTT/ VOX transmitter
relay con trol as wel l as adjusting the sensi ti vi t y of
the VOX circuitry. The PTT p osition p rovides
pus
�
- to-talk opera ti on fro;n
a
microphone PTT
switch or a foo tswitch. The MOX p osition prov ides
manual transmit . I t must be re turned to the PTT
p osition for receiver recovery .
( 19) APF
FREQ
'l
This k nob , whe n actuated by turning on the APF
sw itc h , provides manual con trol for peak ing the
audio peak fi lter (APF) circuit on the d esired
signal. This control will find its chief use fulness
on CW , because its bandwid th is much t oo n ar row
for n ormal SSB recep tion.
( 20) SQL/MIC GAIN
The SQL and MIC GAIN controls are mounted on
concentric shafts. The SQL control sets the squelch
threshold level for FM reception.
· The MIC GAIN con trol varies the au dio level from
the microphone amplifier stage. The control has
su fficient range to perm it·' the use of any low im­
pedance
(500
-
6 00 Oh m) . crystal or dynamic
microphone . Clockw ise rotation increases the leve l
of output from the microphone amplifier stage.
( 2 1 ) FUNCTION SWITC HES: AM GC , APF/M ONI ,
AGC , PO/IC/ALC, and NB/MARK
T he AMGC swi tch activates a micropho ne gain
threshold circuit which requires a particular
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