Fisher 700-T User Manual

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1531 MULTIPLEX DECODER
TEST POINT JO SCA TEST POINT
; 404 OUTPUT 403 :
WOLTIPLEX ALIGNMENT [oto Gene, ae ae ek ate eae in. ee BOARD VIEWED FROM COMPONENT SIDE
¢R402 402
Twa methods of aligning the multiplex decoder are given, The o— ®
Seeced procedure uses a multiplex generator with RF and
9 Hs outputs and with } kHz modulation, such as the Fisher 40 ey es
Moc#e! 300 Multiplex Generator. This is the betrer method of PCAOI. ae
Pow, o- | 14k aicut
aliggnment since the front end and IF stages are also checked Galo 73> Tel rae Posos S.—. * ca22 a) To ounue
|
]
408 fels |
throough the use of this procedure. An alternate procadure for ) | ‘ EN Py? i
vse with multiplex generators not having an RF output is clso 87 2) °| {t | | “Pio \a hi | |
Hien: aal 3} @| | se| ele.
+24V-—_-€@) : aT |
Tale! | 88
PREFERRED ALIGNMENT PROCEDURE Te i [OR 48 § (=) wl 4
ay ai 100 ‘ef!
ae Set MUTING switch to OFF and SELECTOR switch to FM | c406 oe C407, ,4700 cs “ Feel |
ears
;
AUTO.
|
ey
T
ae
|
@ Connect MPX generator to the LOC antenna terminals. Use H , : : RAos 10K eo LSM e — 8 [ye |
two 120-ohm composition resistors in series with the genera- gal a ‘ 2 PR ee ¥ & se,
“ Pkmetend .
ag
—_
SCA
Ze)
(ea
ce)»
fs
og
OBS
GS
°°
&
30
@ Follow procedures given in Toble 1 below. : INPUT | ; R401 72401} ,Q402 / aw [% CR403 \Eej sd ife e $& | |
NOTE: Check the alignment of the IF amplifier before align- | fe 120K S f@E Hef oo“ cour gy s : | S Se) |
: fo Co) ey .o2u 0 cra04 oe I 5
ing the MPX decoder, Poor IF alignment ¢an make proper c40l N Be o——_}q—2 2 |[e2 79]
multiplex adjustment impossible. | zsurle)te) % 7 aaa 3.3K RAZ i om mee !
NOY a Sanaa a ~
: 2, ne Re £eN
[ee a? ¢] (ce) (es ce) Say | (igs
ALTERNATE ALIGNMENT PROCEDURE input te Se ab ic sl = N104 a4 / Soa8e 4 ae ates
& \Eot 7 el2
< ej; \e € 4H
Set MUTING switch to OFF and SELECTOR switch to FM TEST POINT gp] . $ N egy \e few | @-——_ LEFT
AUTO. 402——_—@) $ = IWF ZS Gaia 2 1 | Rau | output
@ Disconnect wire going to connection 4C on the multiplex | 7” q 3 4 2) Ve/ e3 27k |
board. Connect MPX generator to connection 4C. | a eT ae welt fe : l
@ Follow procedures given in Table 2 below. 50K O&O oak :
@ After alignment is complete, disconnect MPX generator and : | en, 2 R43 ik ; { FIGURE 1. Lissajous pattern for MPX alignment.
raconnect lead coming iN connection 3K on the IF board to L. ; _!
connection 4C on the multiplex board, OR ee Ae NAR 4G000 ee ee NS 3 gO
os : ; P1531
Beacon ae ee % NOT USED ON ALL CHASSIS i
. TABLE 2
TABLE 1
MULTIPLEX ALIGNMENT USING COMPOSITE MULTIPLEX SIGNAL
MULTIPLEX ALIGNMENT USING RF MULTIPLEX SIGNAL site a sca oat to St tT Se
GENERATOR MODULATION INDICATOR PURE ANG WER er eck cael
ek EE INDICATOR TYPE AND ALIGNMENT CONNECTION ADJUST INDICATION
STEP] GENERATOR MOOULAT . | aoust | 7
CTION
* iseNiduaoracs ADJUST INDICATION 19kHz (ke) pilot only. DC VTVM to TP401 Z401 top & Maximum DC VTVM reading,
7 :
' 19kH2z(ke) pilot only. £7.5kHz | OC VTVM to TP401 Z401 top & Maximum DC VTYM reading. bottom, 2402 7 7 ;
3
1
(ke)
:
bottom,
2402
2
Short
connection
4F
to
Stereo
Beacon
should
light.
q d,
3 = angela eo Sa aaa a io 7 a a
ne
ground.
3
Connect
portion
of
19kHz
Vary
0
Scope
vertical
input
through
Stable
Lissajous
pattern
2:1
: ; - . ; ‘ (ke) generator output to to 50mV{ 1 megohm resistor to (Figure 1) as slow moving
3 ria ee phi 7 pie Pea fa ties icles scope horizontal input. TP403; scope set for ex- es possible.
¢) generator output to megohm res ;
scope horizontal input. TP403; scape set for ex- possible. ea sie a: pagina ates ath at Sant ee ter wn Be Gute ae thera
ternal sweep, Same us Step 3 Vary 0 S § i i ;
: 3 y aino us Step 3. Z403 bottom Maximum seupe amplitude;
7
TES
ses
SS
aaa
|
4
to
50inV
at
adjust
2403
top
as
neces-
Same
as
Step
3.
Same
as
Step
3
Z403
bottom
Bae
Elbe
ise
oe
ees
ay
|
sary
for
slowest
moving
for slowest moving Lissajous. Lissajous.
Di tion 4F ~ a
tom ground. ed 2
;
:
-
:
,
Composite
MPX
signal
100mV
Audio
(AC)
VTVM
and
Maximum
audio
AC
VTVM
Composite
MPX
signal
VkHz
Audio
(AC)
VTVM
and
Maximum
audio
AC
VTVM
6
VkHz
(ke)
on
left
channel
(560mV
scope
input
to
left
channel
teading;
clean
]kHz
(ke)
(ke) on left channel only. scope input to left channel reading; clean JkHz (ke)
only. P-P). output on preamp board. sine wave on scope.
Minimum audio AC VTVYM
reading at least 30 db below
reading in Step 6.
output on preamp board. sine wave on scope.
Composite MPX signal 1kHz
(ke) on right channel only.
100mV
(560mV
P-P)
Same as Step 6. Separation
Control*
Minimum audio AC VTYM
reading—at least 30 db
below reading in Step 6,
Composite MPX signal 1kHz
(ke) on right channel only.
Same as Step 6. . Separation
Control*
Audio (AC) VTYM and Same gudia AC VIVM tead+ Same-ae Ste p.7: eon Audio eine) e end ; some ranean vq Bhs aot
scope input to tight ing as obtained in Step 6 iad scope inpu Orig ut channe ng Gs G taine in tep
R-P) output on preamp board, (°2 db), clean IkHz (ke) sine
wave on scope.
Minimum audio AC VTVM
teading~at least 30 db below
reading in Step 8.
channel! output
on preamp board.
(42 db); clean IkHz (ke) sine
wave on scope,
100mV
(560mV
P-P)
Same as Step 6.
Minimum audio AC VTVM
reading~at least 30 db below
reading in Step 8.
Same as Step 8.
_
T9kHz (ke) pilot only. £3.5kHz | OC VTVM to connection Trigger Stereo Beacon lights up with T9kHz (ke) pilot only. ates DC VTVM to connection 4F.] Trigger Stereo Beacon lights up with
(ke) AF. Control 0.8 V reading on DC VTVM. ioe Control 0.8 V reading on DC VTVM.
"NOTE: Separation Control is located on preamplifier board. ; “NOTE: Separation Control is located on preamplifier boord.

Fisher 700-T Specifications

General

Brand	Fisher
Model	700-T
Category	Receiver
Language	English