Sharp GF-575H Service Manual page 14

3. Use a non-metallic alignment tool.
4. Repeat adjustments to insure good results.
AM IF/RF ALIGNMENT
(Refer to Figure 26-9)
SIGNAL GENERATOR RECEIVER
STEP PANE
ee CONNECTION TO | INPUT SIGNAL
SDILST MENS
|
RECEIVER
FREQUENCY
DIAL SETTING
REMARKS
Refer to Figure 26-1. Exactly 455 kHz: High end of dial. Adjust for Adjust the AM
, MW IF
(GF-575H)
(minimum capac-
best "IF"
tF transformers.
Exactly 468 kHz:
ity)
curve
(T3, T4)
(GF-575E)
= =
4
T
: f+ ;
t
Refer to Figure
26-2. Exactly 145 kHz.
Low end of dial.
Adjust for Adjust the LW local
2 LW
(400 Hz, 30%, AM
(maximum capac- maximum
oscillator coil (L9).
Band modulated) i ity). output.
Coverage Same as step 2. Exactly 295 kHz. High end of dial. Same as step 2. | Adjust the LW local
3 LW
(400 Hz, 30%, AM (minimum capac-
oscillator trimmer
modulated)
ity).
(C71).
i Same as step 2.
Exactly 170 kHz.
| 170 kHz.
Same as step 2.
Adjust the LW
4 | LW
(400 Hz, 30%, AM
|
bar antenna coil (L7).
modulated)
See '
t——-++————_,
Tracking
+ pe
Same as step 2.
Exactly 270 kHz.
270 kHz Same as step 2.
Adjust the LW
5 LW
(400 Hz, 30%, AM
antenna trimmer
|_modulated)
i
(C58).
6 LW Repeat steps 2, 3, 4, and 5 until no further improvement can be made.
|
Same as step 2.
Exactly 510 kHz,
[Show end of dial.
Same as step 2.
Adjust the MW local
7 | MW
(400 Hz, 30%, AM
(maximum capac-
oscillator coil (L10).
Band
modulated)
ity).
Coverage
| Same as step 2.
Exactly 1650 kHz.
High end of dial.
| Same as step 2. Adjust the MW local
8 MW
(400 Hz, 30%, AM
(minimum capac-
oscillator trimmer
modulated)
| ity).
(C69).
Same as step 2.
Exactly 600 kHz.
| 600 kHz.
Same as step 2.
Adjust the MW
9 | MW
(400 Hz, 30%, AM
|
i
bar antenna coil (L7).
modulated).
See
|Note Aj .
Tracking : 4 2 4
Same as step 2.
Exactly 1400 kHz.
1400 kHz.
Same as step 2.
Adjust the MW
10
MW
(400 Hz, 30%, AM
antenna trimmer
modulated)
|
L (C56).
11 i MW
Repeat steps 7, 8, 9 and 10 until no further improvement can be made.
Refer to Figure 26-3.
Exactly 5.85 MHz.
Low end of dial.
| Same as step 2.
Adjust the SW local
12
sw
(400 Hz, 30%, AM
(maximum capac-
oscillator coil (L11).
Band
modulated)
| ity)
——
4
Coverage Same as step 12.
Exactly 18.5 MHz.
High end of dial.
Same as step 2.
Adjust the SW local
13 SW
(400 Hz, 30%, AM
(minimum capac-
oscillator trimmer
modulated)
| ity)
(C67).
|
| T
Same as step 12.
Exactly 6.5 MHz.
|
6.5 MHz.
Same as step 2.
Adjust the SW
14 SW
(400 Hz, 30%, AM
antenna coil (L8).
modulated)
++ Tracking | +
Same as step 12.
Exactly 16 MHz.
16 MHz.
Same as step 2.
Adjust the SW
15 SW
{400 Hz, 30%, AM
antenna trimmer
modulated) ' (C54).
see
i
i
it
16 | SW |
Repeat steps 12, 13, 14 and 15 until no further improvement can be made.
|
Check the alignment of the receiver antenna coil by requires less inductance. Change loop inductance by sliding the
bringing a piece of ferrite (such as a coil slug) near the antenna bobbin toward the center of ferrite core to increase induct-
loop stick, then a piece of brass. If ferrite increases output, ance, or away to decrease inductance.
loop requires more inductance. If brass increases output, loop
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