PHILCO-FORD "S" LINE TELEVISION RECEIVER CHROMA BANDPASS ALIGNMENT
USING THE MODEL 415
TEST EQUIPMENT CONNECTIONS:
Preliminary:
Bias Supply:
Oscilloscope:
Signal Gen:
A. Disable horizontal sweep section, remove ground connection from cathode (pin
#2) of horizontal output tube
6KD6 (V201). (May be omitted
if desired.)
B. Set "Normal/Service" switch (SW36) to "Service" position. (May
be omitted if desired.)
C. Set color control to maximum (fully C.W.).
D. Using Model 415 bias supplies, apply approximately +12 VDC lo lug M4 and adjust for 2.2 VDC at M9;
apply -5 VDC to lug M42.
E. Connect to Model
415 as indicated in Figure 5.2 (Fold-out at end of Manual). Connect PR-151 to M51 for
Step
1. to M50 for Steps 2, 3 and 4. Connect Direct cable to video detector test point (Lug Ml4 on VIF panel P2).
F. Not required; use internal markers of Model 415.
Sweep Gen (Model 415):
G. Connect r-f cable of Model 415 directly to Lug
M43 for Steps l and 2. using 75-ohm impedance (marker box
not required).
Connect r-f cable of Model 415 directly to antenna terminals of receiver for Steps 3 and 4. using 300-ohm
impedance (R-F modulator not required).
R-F Modulator:
H. Not required.
VTVM:
J. Connect lo lug Ml4; adjust Model 415 output for 0.5 VDC for Steps 3 and 4.
NOTE: When performing
alil}nment by injecting the r-f sweep at the antenna, first adjust the receiver fine tuning using the Sound trap
for reference as outlined in the note following the
AM ALIGNMENT CHART. Then proceed as indicated below.
MODEL 415
MARKER
STEP CONTROLS
FREQUENCIES*
ADJUST
REMARKS
,_
ALIGN CHROMA BANDPASS
FUNCTION SW. TO VIDEO.
41.25 (4.5)
L40 TOP AND BOTTOM
CONNECT PR-151 TO
M51,
TRANS. L40
PROBES SW. TO DEMOO. 41.67 (4.08) CORES
ADJUST L40 TOP & BOTTOM
42.17 (3.58)
FOR
RESPONSE CURVE
FIG-
42.67 (3.00)
URE "B".
MAINTAIN EQUAL
MARKER HEIGHT.
2.
AUGN CHROMA COUPLING SAME AS STEP 1
SAME AS STEP I
L4t
CONNECT PR-151 TO M50.
COIL L41
ADJUST L41 FOR MAX 3.08
MHZ, CURVE WILL BE TILTED.
3.
ALIGN CHROMA
TAKEOFF
FUNCTION SW. TO IF. SAME AS STEP 1 L38
ADJUST L38 FOR MAX 4.08
COIL
L38
PROBES SW. TO DEMOO.
MHZ.
CHROMA SW. TO ON.
4.
CHECK OVERALL
CHROMA
SAME AS STEP 3 SAME AS STEP I
L40 (TOP CORE)
CHECK CURVE FOR RESPONSE
RESPONSE
FIG.
17 "A"
IF
NECESSARY
RETOUCH
L40 TOP FOR
CURVE FIG, 17 "A".
*FOR MARKER FREQUENCY RELATIONSHIPS AT R·F, l·F ANO VIDEO/CHROMA SWEEP FREQUENCIES, REFER TO SECTION 3.8 a FIGURE 3.3 OF THIS MANUAL.
77
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