Fisher ALLEGRO A 19 Service Manual

Page 12

ALIGNMENT INSTRUCTIONS . MULTIPLEX SECTION

GENERATOR INDICAIOI ALIGNMENT
nr
srzps CONNECTION "£351ch 33%} comgcfiw Amusr INDICATION NOTES
Audio oscillator AC VTVM to iunetiarl L100 (Ula hex . .
1 mm, ,0 lug I no KC-l volt None at c210 and R223 Ham. MI) Mmlrrlurrl when.
Multiplex g. orator 19 K: (:5 m) 11mm and
2 audio output to pilot tone, None DC VTVM to 1.51. 101 bottom (Us. I... Maxlmum voltage 1
Inc 1 (5.. Note I) 100 my alignment ml)
571"; hm" inf", M 2101 St hi 2 1 L' ~
~ I out ut 0 en.,- a e : Mama;
3 Same at step 2 9 5'25 None mm input to iundion jun K-tvun pattern, Disregard I
«5:216 and not allgnment tool) phan at pattern
xterna sweep
VaryK merotor Luge-11:: pattern
4 Same a: Step 2 19 KC None Same as Stop 3 12,. 33",? ,IJI;2:I,,;',,"J::",.I, 1. 2
mo mv =1.qu I50 mv range
Ac vrvm and none
(Imgfimfli: «no input to channel 1100 I Maximum indication on
5 Same as Step 2 I I. . None A output lug. (m. [m m.) Ac vrv . lean woo 1,:
V" "m Internal "mm cpl wavetorm on scope
In P-P) oc VTVM to 1251?. lol
. Minimum readin an
1000mm M A: VTVM I, I I.
(I) channel on y. MPX reparation °° '
s 51 2 N s s. 5 at least :1: db below 1
6 ame as ea 'd'il'p'fi one ame as to R2I5 "win! obtained in
- ' Step 5
Move scope input and Note and record
7 Same as Step 2 Some or Step 6 Non. Ac VTVM to channel a -- voltage reading 1
output lug on AC VTVM
(1,801?n m a," lett h Af; 11m lreadigg db
c anne on y, ____ 1 cu e at east
3 5"" ° 5"" 7 1 volt rms N°"' 5" ° 5 7 below reading observed I
(2.8 P»P) in Step 7
WW °" " " Ac V'I'VM readin
fl
9 Same as Step 2 (5) fang" in Na... slam. ul Step 7 - should 5. the mm. a. I
In I observed m Step 7
(mm. o'n kin h AfiiVbTVM feuding db
e onne on y, ____ s ou e at «no
10 Same as 51.; 2 I vol, ,m None Same as so.» 7 MW main, mm! 1
(2.3 M) in Step 9
Re eat Steps 9 and 10 with scn e and AC VTVM connected to channel A output lug, but start with
H s o 4,. applied to Im channe for first reading, um. mud. to II.» channel for lecond reading.
Multiplex generator 100% .
12 'F '9'" "I °°° 9' °" "" <75 KC D'V-I [6 W123: Llii'nli'i - 55%;333315 A
film?" *"°"""°"" 14:12:, mm: MM
WWII/"WIT? 1?"
IBM cps on right Same as °"
1: Same as so» 12 Same as Step 12 R215 at least 33 db below I
(I) channel only Step 12 'dhg Immd In
ten 12
Ac vrvu readin
14 s s, 12 mo an on I. Same as s s 12 ___ should he 10 db 5.3,». 4
°"" °' '9 (A) channel only Step 12 m "F readin observed in
ran 1?
Ac Vl'VM d'
15 5."... a, 5., 12 5000 m on right Same as Same m 5,. 12 should be 23,5: 13?»:
P (a) channel only Step 12 F -~- reading observed In
ten 12

NOTE: The above procedure is based on the use of the FISHER Model 300 Multiplex Generator.

I - In steps 2 through H, the audio output of the Multiplex Generator
should be connected to lug 1 of the multiplex xub-chauix through a
l2,000 ohm, Vszatt, corbon resistor, and a 180 uut capacitor should
be connected between lug I and ground. The wiring from the MPX
TEST lock on the main chuuis to lug I must be dilconnected during
Steps 2 through 11.

2 - The vertical amplitude of the Lissoiou: pattern will increase slightly

ax the generator output ix increased. This is a normal occurrence.

3 - If DC VTVM reading falls below -9 volts when maximum reading
is obtained on the AC VTVM, readiust bottom of 1100, then repeat
Step 5. Repeat this procedure until maximum AC VTVM reading is ob-
tained with DC VTVM reading greater than -9 volts.

4-Tune the FISHER to the RF output frequency of the Multiplex
Generator