B&K 415 - Other Uses of the Model 415; Alignment of FM Receivers Using the Model 415

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PHILCO-FORD "S" LINE TELEVISION RECEIVER
CHROMA BANDPASS ALIGNMENT · ALL CHASSIS
Test Equipment Connections:
STEP
Preliminary: A. Disable horizontal sweep section, remove ground connection
from cathode (pin
Jt2) of horizontal output tube 6KD6 (V201).
B. Set "Normal/Service" switch (SW36) to "Service" position.
C. Set color control to maximum (fully C.W.)
Bias Supply: D. Apply approximately
+ 12VDC to lug M4 and adjust for 2.2VDC
at M9, apply-5VDC to lug M42.
Oscilloscope: E. Using direct probe connect to chroma detector block, con-
nect chroma detector to lug M51 for step 1, to M50 for steps
2, 3 and 4. (See figure 8 for chroma detector circuit)
Signal Gen.: F. Connect as shown for steps 3 and 4.
Sweep Gen.: G. Connect in series with absorption marker box and
O. lmf
capacitor to lug M43 for steps 1 and 2, set generator for
video sweep to RF modulator for steps 3 and 4.
RF Modulator: H. Connect as shown for steps 3 and 4.
VTVM:
J. Connect to Ml4, adjust sweep input for .5VDC for steps 3
and
4.
SWEEP
SIGNAL
ADJUST REMARKS
GENERATOR GENERATOR
ALIGN CHROMA BAND ... 3.5MHz SWEEP WIDTH L40 TOP AND BOT• ADJUST L40 TOP 6: BOTTOM FOR RESPONSE
PASS TRANS. L40
AT 3.58MHz CENTER
TOM CORES CURVE FIGURE "B"• MAlNTAIN EQUAL MARKER
FREQ.
HEIGHT.
CHROMA DETECTOR TO M51o
ALIGN CHROMA COU .. SAME AS STEP 1 L41 ADJUST L41 FOR MAX.
3.08MHZ. CURVE WILL
PLING COIL L.41 BE TILTED. CHROMA DETECTOR AT M50.
ALIGN CHROMA TAKEOFF' 0¥5MHZ (J·F) RF' VID£0 L38 ADJUST L.38 f'OM MA.Xo 4.06MHz.
COIL L38 CARRIER
CHECK OVERALL CHROMA
0-5MHZ (I-Fl
RF VIDEO
L40
{TOP CORE)
CHECK CURVE F'OR RESPONSE FIG. 17''A''.
RESPONSE CARRIER
!F NECESSARY RETOUCH L40 TOP FOR CURVE
FIG.
17"A".
__j
NOTE: WHEN FEEDING IN AT A-F THE VIDEO CARRIER MUST BE AT CRYSTAL ACCURACY AND THE FINE TUNING SET FOR ZERO BEAT BETWEEN THE VIDEO
CARRIER ANO A CRYSTAL
OSC, AT 45,75MHz WITH CHANNEL SELECTOR AT THE PFl:OPt.R CHANNEL FOR THE 'RF VIDEO CARRIER.
/
[]
P2Yif
& OH PANEL
M16
APPLY APPROX
12.VOC
BIAS
ADJUST FOR
1.2VOC AT M9
TO
swm
m.
Pl CHROMA PANfl
0 SW36 0
IORN. SU¥.
AOJUST TOP CORE FOR
CtlRVt: FIC."A"
ADJUST TOP & BOT.
FOR CURVE
FIC
"B"
Figure 17. Chroma Bandpass Alignment and Bandpass Curves
Courtesy of Philco-Ford Corporation
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