Sharp GF-777H - Alignment Instruction

GENERAL ALIGNMENT INSTRUCTION
Should it become necessary at any time to check the alignment of this receiver, proceed as follows:
1. Set the volume control (VR508) to maximum. 5. Set the function selector switch (SW102) to “radio”
2. Attenuate the signals from the generator enough to swing position.
the most sensitive range of the output meter. 6. Set the fine tuning control (C60) to mechanical center
3. Use a non-metallic alignment tool. position.
4. Repeat adjustments to insure good results.
AM IF/RF ALIGNMENT
(Refer to Figure 15-9)
TEST SIGNAL GENERATOR RECEIVER
STEP|BAND | craGE | CONNECTIONTO | INPUT SIGNAL ee canues ROUSE
RECEIVER FREQUENCY
i Refer to Figure 15-1. Exactly 455 kHz: High end of dial. Adjust for Adjust the AM
1 Mw IF (GF-777H) (minimum capac- best “IF” IF transformers.
Exactly 468 kHz: ity) curve (T3, T4)
(GF-777E) it
Refer to Figure 15-2. Exactly 145 kHz. Low end of dial. Adjust for Adjust the LW
2 LW (400 Hz, 30%, AM (maximum capac- maximum oscillation coil (L9).
Band | toailetet ity). output.
|— -—---+-—-. +} a a
Coverage Same as step 2. Exactly 295 kHz. High end of dial. Same as step 2. Adjust the LW
3 LW (400 Hz, 30%, AM (minimum capac- oscillation trimmer
modulated) ity). (C71).
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).
Hack: modulated) See [Note A] A}.
|—___+————_| Tracking
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) (C58).
6 LW Repeat steps 2, 3, 4, and 5 until no further improvement can be made.
Same as step 2. Exactly 510 kHz, Low end of dial. Same as step 2. Adjust the MW
7 MW (400 Hz, 30%, AM (maximum capac- oscillation coil (L10).
Band modulated) ity). ;
Coverage Same as step 2. Exactly 1650 kHz. High end of dial. Same as step 2. Adjust the MW
8 Mw (400 Hz, 30%, AM (minimum capac- oscillation trimmer
modulated) ity). (C69).
|e ee
Same as step 2. Exactly 600 kHz. 600 kHz. Same as step 2. Adjust the MW
9 MW (400 Hz, 30%, AM bar antenna coil (L7).
modulated). See |Note A] .
-——_——, Tracking
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) (C56).
11 MW Repeat steps 6, 7,8 and 9 until no further improvement can be made.
Refer to Figure 15-3. Exactly 5.85 MHz. Low end of dial. Same as step 2. Adjust the SW
12 sw (400 Hz, 30%, AM (maximum capac- oscillation coil (L11).
Band modulated) ity)
Coverage Same as step 12. Exactly 18.5 MHz. High end of dial. Same as step 2. Adjust the SW
13 SW (400 Hz, 30%, AM (minimum capac- oscillation trimmer
| modulated) ity) (C67).
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).
ra
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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