B&K 415 - Page 77

PHILCO-FORD "S" LINE VIDEO IF AM AND SWEEP ALIGNMENT PROCEDURE USING THE MODEL 415
Preliminary: A.
B.
C.
Bias Supply:
D.
The following video
IF alignment is based upon a tuner with proper bandpass alignment connected to the TV
chassis.
Disable horizontal sweep section by opening jumper from cathode of horizontal output tube 6KD6 pin
#2 to ground
and place "Normal/Service" switch
in "Service" position. (This step may be omitted if desired.)
Preset VRl sound rejection pot. and VR2/AGC distribution pot. to approx.
¼ turn CW.
(Use Model 415)
Apply approx. 10.5 VDC to M4 (AGC) and adjust for 2.2 VDC at M9 (Tuner AGC). Adjust VR2 (AGC) for 6.0 VDC
at IF AGC T.P. (Test Point).
Oscilloscope:
E.
Connect as in Figure 5.2 (Fold-out at end of 415 Manual). Connect Direct cable of Model 415 to lug Ml4 on VIF
panel (P2).
Signal Gen. (415):
F.
Set FUNCTION Switch to MOD MKR position. Connect Model 415 to UHF input (J2T) using short length of stiff
wire to contact center pin of connector. Select 75-ohm impedance. Set channel selector to UHF.
AM ALIGNMENT CHART (Use one marker at a time)
MODEL
415 MARKER
STEP FREQUENCY
ADJUST
REMARKS
I
44.00 MHZ
L6
(BOTTOM) FOR MAX.
PEAK
-
L6
(BOTTOM), L9, L10,
& L13 AT THEIR
RESPECTIVE FRE-
2
44.00 MHZ
L9 a LIO FOR MAX.
Ql)ENCIES FOR MAXIMUM DEFLECTION ON SCOPE. USE PEAK WITH
CORE NEAREST TOP OF COIL. ADJUST SIGNAL GENERATOR INPUT
3
42.75 MHZ
L13 FOR MAX.
AS NECESSARY TO MAINTAIN 1.0 V P/P ON SCOPE.
4
USE PIX (45,75)
AND
UT FOR MAX. (ON TUNER) PEAK
L1T AT 45.5 MHZ. ADJUST SIGNAL GENERATOR INPUT
AS
OPTIMIZE
IN
STEP 9
NECESSARY FOR 1.0 V P/P ON SCOPE. PEAK
L1T WITH CORE AT
BELOW.
TOP
OF COIL.
s SOUND (41.25)
L6 (TOP) FOR MIN.
ADJUST
L6 (TOP) AND VR1 IN THAT ORDER FOR MINIMUM DEFLEC-
TION
ON SCOPE. INCREASE SCOPE GAIN IF NECESSARY FOR SUFFI-
6
VRI FOR MIN.
C!ENT INDICATION. REPEAT STEPS 5 AND 6, ADJUST
Ll2 FOR
SOUND (41.25)
MINIMUM DEFLECTION. ADJUST LI I ANO L14 IN THAT ORDER FOR
MINIMUM DEFLECTION. INCREASE SCOPE GAIN
IF NECESSARY FOR
7
38.75
MHZ*
Ll2 FOR
MIN. (TRAP)
SUFFICIENT
INDICATION.
REPEAT STEP 8. KEEP ALL CORES AT
COIL ENO AWAY FROM BOARD.
8
ADJ SND (47.25)
Lll ANO L14 FOR MIN. (TRAPS)
REMOVE MODEL 415 R-F CABLE FROM J2T.
•usE SPARE MKR OSCILLATOR CRYSTAL-CONTROLLED OR AS A VARIABLE-FREQUENCY OSCILLATOR (REFER TO SECTION 5.6 OF MODEL 415 INSTRUC~
TION MANUAL).
NOTE: TO POSITION FINE TUNING FOR SWEEP ALIGNMENT USING
R~F SWEEP,
(f) SET TUNER TO CHANNEL 4.
(2) PLACE FUNCTION SWITCH OF MODEL 415 TO CH 4 POSITION AND CONNECT R-F CABLE TO ANTENNA TERMfNALS. USE 300~0HM IMPEDANCE.
(3) DIRECT CABLE REMAINS AT LUG Mt4 OF VIF PANEL.
(4) REFER TO PAR. 6.1.1 t OF MANUAL FOR METHOD OF SETTING FINE TUNING USING THE SOUND TRAP NOTCH.
Sweep Gen. (Model 415): G. Connected to antenna terminals of receiver.
Signal Gen. (Marker): H. Not required; use internal markers of Model 415.
STEP
9
10
11
SWEEP ALIGNMENT CHART
MARKER
MODEL 415 CONTROLS FREQUENCIES*
ADJUST REMARKS
FUNCTION SW. TO CH 4. SOUND (41.25)
Ll3
VSE SOUND MARKER REFERENCE TO
ADJUST FINE TUNING,
CHROMA
SW. OFF. SWEEP CHROMA (42.17} LlT (ON TUNER)
SET SWEEP FOR 1.0 V P/P ON SCOPE.
ADJUST
FOR MAXIMUM
WIDTH MAX.
THEN AD-
PIX (45.75) GAIN AND RESPONSE
FIG. 16A. ADJUST SWEEP
INPUT TO
JUST AS REQUIRED. MAINTAIN
1.0
V
p/p
ON SCOPE. Ll3 ADJUSTS
42.17
MHZ
MARKER ANO LlT ADJUSTS 45.75 MHZ MARKER.
ADJUST
L9
TO TILT FOR FLAT RESPONSE.
SAME AS ABOVE SAME AS ABOVE
L9
IF L9 DOES NOT GIVE Fl.AT RESPONSE,
L6
(BOTTOM)
CORE
MAY
BE ADJUSTED FOR FLAT RESPONSE.
IF L6 IS ADJUSTED
REPEAT STEPS
5
ANO 6
IN "AM ALIGNMENT''
PROCEDURE.
"DO NOT TOUCH
L10.''
OBTAIN FRINGE CURVE AS FOLLOWS:
A. REMOVE BIAS FROM M4:
(APPLY
SLIGHT BIAS IF NECESSARY TO REMOVE NOISE LEVEL INTERFERENCE).
8. LOWER SWEEP
INPUT TO MAINTAIN 1.0 V P/P SCOPE
IS NOT CORRECT REPEAT STEPS 1 THROUGH 10.
•41.25 MHZ IS EQUIVALENT TO 7t.75 MHZ ON CHANNEL 4.
42.17 MHZ IS EQUIVALENT
TO 70.83 MHZ ON CHANNEL 4.
45.75 MHZ IS EQUIVALENT TO 67.25 MHZ ON CHANNEL 4.
DEFLECTION. RESPONSE
FlG,
16B
SHOULD BE OBTAINED.
IF FIG. l6B
75
I