Yaesu FT-767GX, Operating Manual

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To use t he A P F, fir s t t u n e in the d e s i r e d C W
signal with the APF off, and then switch it on
and adjust the APF control for peak volume on
t he desired sig n a l.
Turn the A P F o f f b e fo r e
t u ning t o a n e w frequen cy. S e e a l so § 4. 1 4
'Tips for C W Operation '.
4. 6. 7 I F Passband Shift
The loc a tion o f t h e IF passband r e l a tive to
the c a rri e r frequency o f t he receiv e r in S S B,
C W, AM and FSK modes can be adjusted by the
S H I FT con t ro l (inner k no b on the co n t ro l j u s t
b e low and t o t h e rig h t o f t h e tun i ng kno b ) .
Think o f t his con t ro l a s a sliding windo w a d ­
j us t m ent, which a l lows t h e receiving p a s s b a n d
( window ) t o be s lid b a ck and fo r t h, providing
d i f ferent vie w s of t h e receiving frequen cy.
No r m a l l y, the S H I FT con t rol is ke p t in the 12
o ' c lock posi tio n u n ti l a desired sig n a l h a s
b e e n t u n e d in. Then, if the sig n a l is b ei ng
i n t e r fered wi th by a no t h e r sig n a l j us t above
o r b e low the d e s i r e d o ne, t he S H I FT con t ro l
c a n be a d j u s t e d to t h e l e f t or rig h t, r e s p e c ­
tive l y, to move t he p a ss b a n d w i n do w f a r t h e r
f rom t h e inte r fe r e n c e. No t i c e a l so t h a t t he
audio ton e c h a r a c te r i s t i cs o f the rece i ve r
ch ange : t h i s i s use f u l i n A M recep t io n , s u p ­
plementing the TONE control.
Not e :
Before adjusting the S H I FT control,
m ake sure t h e NOTCH fi l t e r i s s w i t ch e d
o f f. A l so , r e t u r n the S H I FT con t ro l to
the 12 o ' c lock pos i tion when t u n i ng to
ano t h e r fre quency.
4. 6. 8 I F N o t c h F i l t e r
The I F no tch fi l t er p ro vides a m e a n s t o s u p ­
press c a r r i e r h e t e ro d y n e i n t e r f e r e n ce i n S S B,
C W, AM and FSK reception. The notch is acti­
vated by the s wi t c h of the s a m e n a m e to the
left o f t h e t u n i ng k nob, and adj u s t e d b y the
inner knob o f the middle control at the bottom
right. Whi l e a c t i v a t e d, t h e indi c a tor n ex t to
the NOT C H switch glows green.
The no t c h fi l t e r shou l d be a c tiv a t e d onl y
a f t e r t h e d e s i red s i g n a l h a s b e e n t u n e d i n,
and after the S H I FT control has been adjusted
for mini m u m a d j a ce n t - c h a n n el in t e r ference.
Press the NOTC H swi tch and adjust the control
gradua l l y b ack and for t h to fin d the po i n t
where the unwanted heterodyne suddenly drops.
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I f the h e t e rodyne leve l i s s t ro nge r t h an t h e
de sired sign a l, the S - m e t e r indic a t ion w i ll
d i p when t he no tch i s p roper l y set. Turn t h e
no tch s w i t c h o f f be fo re t un i ng to a ne w fre ­
q u e ncy or adj u s t ing t he S H I FT co n t ro l .
See
a l so § 4. 13. 3 .
4. 6. 9 AG C ( Automatic G a i n Contro l )
I f you h ave been tun ing a round the b an d s you
m ay have already noticed that the main m icro­
processor automatically selects fast AGC when
t he t u n i ng knob i s ro t a t e d q u ick ly.
Th i s
allows you to detect weak signals while tuning
a c ross the b a n d , even w hen s t rong sign a l s are
present.
W h i l e l i s ten i ng to a s t a t io n , you can se lec t
the A G C decay rate that provides the most com ­
fo r t able recep t io n , u sing t h e fou r - po s i t ion
A G C s e l e c tor ( s m a l l kno b , seco nd fro m t he
right, next to D I M ) . Usually, for AM and S SB,
t his wi l l be the ' S ' ( S lo w ) posi tion, b u t whe n
sig n a l s are f l u t t e ri ng, o r when looking fo r a
w e ak signal you m ay fi n d ' M ' ( Mediu m ) o r ' F '
( F ast ) be t t e r, a t l e a s t u n ti l you m ake co n ­
t a ct. For C W, the M e diu m or Fast posi tio n s
wi l l be h e l p f u l a t highe r speeds or u n d e r
noisy conditions wi th w e ak sig n a l s . W h e n t he
band is ve ry quie t a n d sig n a l s are very we ak,
the OFF position m ay provide best copy ( don' t
t ry this i f i t i s noisy ) .