Yaesu FT-101EE - Noise Blanker

VFO UNIT ( PB-10564
» VFO medule board is installed in the VIO chassis.
VFO uses FET 2SkK19GR ard
25K19GR first 2SCa72Y buffer
cvides isolation and amy VFO sighal:
transisters @1,
has
ation of
buffer,
tor
Lie
The VFO aseillation frequency is 8700 KHe to 9200
Kilz. and the tunable IF range of 500 KHz.
Dl, 18145 in series with
Cl4 is santehed imto the eireuit
COYErS
Varactor diode apacttor
ay the clarifier
and the relay contacts to shaft the VIO frequeney for
receiver
Ssaiteh
offset tuning,
PR-1292
FIX PROCESS UNIT
Cf Ta: TOROF
So oth 3 Fale ea Fe ff ny Taste
:
Ot)
tale
ce
ie
ae
Sass
c ie ol ae
Sta
! s= 3
se a
Laas
aS
pRacesah
on. ——
LE #hGeH
GL oy EN
ALE Mid = _ ——
THsT- Qo — =
be
ieee
———K————————
(&) NOISE BLANKER LKIT (PR1292)
S180 KRHs cutout
fect
abel Ea he sienal amplified
the IF amplifier Qs
ciode Dr.
the IF
LISS,
The
2nd mixer ts
PSS TAY
nv OQ? is. fed
2S TSR: throuch
signal from the recerwer
s hase of IF “amplifier @Q2.
threuch
ta the gate col
the noe blanker
IS1555.
and
then
amplified
by
Qa
ancl
bec
i
amplifier
chain
in
the
low
frequeney
IF
unit
PB
S180 KHz signal is also
OM,
7 eA
above fal to the ate of
noise a iy Wier
ancl GS. ZC
SSK 19GR and amplified through (4
a a
Pulse rectifier diode D4, 1Si555 conducts with the noise
pulses in the output from QS. and negative output voltage
25K 34E in
n the noise blanker driver Q7,
irom the diode 15 applied ta the gate of Qe,
order to turn off Q6.1]
PSC372Y conducts to switch a noise blanker diode D2,
which
disconnects
the
input
¢ireut
of
the
[FP
amplifer
QS whenever the noise pulse exists.
The
switching
level
is
adjusted
by
the
noise
blanker
WRI.
there tay
threshold control At the most effective blanking
Position,
3@
slicht
distortion
on
the
received
signal due to mixing at the switching diode. This effect
can
be
reduced
by
adjusting
the
t
comtral
slightly.
(9)
CRYSTAL
CONTROL/RF
PROCESSOR
UNIT
(PB-1534)
This
model
the
VFO
unit.
The
interconnection
of
the
modules
is
wired
directly
is located on
without using plug-in socket.
Q3 25KIR5R