AM Tuner
o Connect the AM SG (AM signal generator) to
the AM ANTENNA terminal via 1kQ resistor'
o Switch the FUNCTION selector to the AM posi-
tion.
1. Set the SX-3900 dial pointer to 600kHz, and
the AM SG output to 600kHz, 100d8 (modula-
t i o n 4 0 0 H 2 , 3 O % ) .
2. Adjust the core of T3 to maximum demodu-
lated output (at TAPE REC terminal).
3. Then set to 1400kH2, and set the AM SG out-
put frequency to 1400kHz also.
4. This time adjust TC6 to obtain maximum
demodulated output (at TAPE REC terminal).
5. Set the SX-3900 dial pointer to 600kHz, and
the AM SG output to 600kHz, 30d8.
6. Adjust the core of T3 to maximum demodu-
Iated output (at TAPE REC terminal).
7. Then set to 1400kH2, and set the AM SG out-
put frequency to 1400kH2.
six-39ocl
8. Adjust TC6 to obtain maximum demodulated
output (at TAPE REC terminal).
9. Repeat steps 5 to 8 above.
l-0. Set the SX-3900 dial pointer to 600kHz, and
the AM SG output frequency to 600kHz.
11. Slide the bar-antenna coil along the core to
find the position which gives maximum demo-
dulated output (at TAPE REC terminal).
12. Tune to 1400kH2, and set the AM SG output
frequency to 1400kH2.
13. Adjust TC5 to obtain maximum demodulated
output (at TAPE REC terminal).
14. Repeat steps 10 to 13 as above.
15. Tune to 600kHz, and set the AM SG output
frequency to 60OkHz.
16. Adjust T4 and F7 to obtain maximum demo-
dulated output (at TAPE REC terminal).
B a r - a n t e n n a
T o T A P E
t e r m i n a l
To AM
A N T E N N A 1 k f ) r e s i s t o r
t e r m i n a l
O s c i l l o s c o p e
A C v o l t m e t e r
A M s i g n a l g e n e r a t o r
F i g . 8 - 5 A M t u n e r a d j u s t m e n t