Technics ST-9030 - In the Absence of Interference; Interference Component; Wide Indicator and Separation at Narrow Time; Muting Circuit

A.
ln
the
absence
of
interferenca
Since
the
coilecror
of
]!+f
S is
lf
ground
potenriat.
TR304
îs
in
,,OFF,,
ii;ffi
;",i::"ij":ffi
j:;:t:ï*:;,'å"J"J"ï:#;iËîïl!Îirtiå[',*.#]i:T*,fä
"ON",
whiie
TR3os
is
broushr
tni;
,,;;l,s;are
due
ro
the
sround
oor
wrDE
rF
sisnar
beins
rransmitred
.
*or.or.niîircuit.
on
ìn-e;-.ü,;îî:l:::ï;:å,;i:¿l*:
:m:t
Í.i
i:iï:;-î),.
ii,fiii;.iîîi;;ï:îlXïåj*;;;;.;;;;;.i,å'å1,,n.
circuit
between
ãia¡n
ano
source,
B
lnterference
component
(Af)
lnrerference
with
s¡ations
at.cjistances
20e
ktz.il
30g
kHz
apart
is
brought
in
questiôn
in
the
san
::ï,r:fiil:1åi,':å,f;:,:TJ..î:;iï,jn,.f
oa"o
wi¿tf'¡I,',;.ï""i:
=1,v
the
,ec"ption
ìJ,ariect.o
oy
a
ln
the
presence
of
¡nterference
'ìce
component
{af)
from
wlDE
lF
c¡rcu¡i.
-
-e'¡
'J
<
Although
TR3O4
is
kept.
in,,,OFF,,
state
by
TR4i5
in
thê
absence
of
interfr
A
(ln
the
absence
or
inrerrerenc.l.
¡iì¿rl'
.oi;:::Ji:,:t:i::_::,::.rrerence
as
expraíned
in
rhe
above
item
:li:iii¿ff
';:1l:'1e'1-!'"1'*1#';,',*i'ii:"JiJtiii:i'åï',ì.:';î:::î^î;i::,i*:m;
bring
TR3o7
i;
..:il:l
this
T8304
"9¡"'
bv
v¡n¡crr,
slm¡tai
oo"r..,o'":io
,nat
in
detunins
is
carried
our
ro
subseguènt.¡l.r¡r.
-"-"'stô.te'.
Therefore,
cjuring
tuning,.,.ràä*.,'*loÄ^o*,rsignal
istransmitted
to
the
@
il::^il-n:ator
and
separation
at
,.NARRoW,,
time
..
+;::T;:ï:,ilHi'ï'::"I"eïïlåf::ïï'Åi*=Uf-,"J#îf':åi,:::LiJï:
iïä?lt?"i1.
iïîl:,
.üi¡*iruï';];:,'
i:ïîl¡f
;:::n
Ì:ltnilirui*;;:,o,s
co
ec,or
i,
noi-ii
i''
na,ed
on
the
ro'¡i
rrequency
cjrêuit
is..ruo,,JJ
ìãi"no.,."rnu
oorr;;;,.;;ño,f;ilr"tl,ïJ,i;:Xlñ*r*ïr""î:::l
intÞrfei'ence"durins
tunins'
the
collector
oiiïäôo
,,
reouceo
to
""á'i,ï"i"1r"tial
and
rR309
is
turneà
,,otrl,,,
y_.Ë:,i:3:J;:'::il{;;,n
'ri
vì."*n,,.,ir.,0
*;;;;;,;;'î,;å;.",.srate,
with
the
besr
separation
ar
C
MUTING
CIRCUIT
i he
mut;ng
circuir
of
this
unit
utilízes
3
circuits
as
shown
in
the
block
díaora¡t
".""r<co
o
(.irrc
o';o
''ii'i'.';;;,"':;?l:"'
ot
f'!'
2'
i'e''
The
mutins
tionourpur.;.ð;i,';;;',":*Tåi,ï;ï,,9.1
jrY..ffi:
curpur
voträge
varyinq
accorcling
,"
;;;ü;;uel,
ano
the
switch
circuit
makin
L
C
rhis
;Ji
;
;;;iä
;:,j,,,
_,i,:ïff.,:1,1ï:l
functioning
rever
anc
muting
band
width
which
have
convenrionaly
been
difficurt
i"
À;;.;;;;;uinuîr,,nn
circuit
utilizing
the
L.C.
tuning
çi¡çr_ri¡,
and
is
also
suf-
ficientty
resisranr
to
overmodutar"o
"ori"ii"
oril.,o,.
of
this
circuit
is
described
below.
Jl-lL
-Lr
tz
{MUTING
SU/ITCH
CI
RCUITJ
Fis.2
O
Muting
band
switch
circuit
[Fig.
3J
A.
.Perfectly
tuned
point
and
ietuned
state
jliÏ;î':
TR4oo
and
rR407
aä'i*""i:'ott"
since
rhe
inpur
voirase
is
or
0V.
wirh
respective
emitrers
being
]ff,ï:'::lî:åi'jlîåjåJi..,*'J::iåï;i:,iffii:;:;tiJåiî:
and
rB40e,o,urn
,hem
,,oN,,
Accordi
'
:il
j1!i
:'ir-."1..:,,i..".....,
swrcH
BAND
SWIICH
5/¡l
LEVE!
swlTcH
¡.1¡Nb
S¡GNAL
@NTROL
L.C
MUÎ.
BANO
E
sr-soso