SLV-F900, SLV-F990 - Sony VCR Service Manual (repair manual). Page 5

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Modulation is performed by the signal that is supplied from IC901 pin@¡ (pin#§).

If IC901 pin@¡ (pin#§) goes to “L”, the resistor R910 (R941) cannot be connected in parallel so that the current flowing through Q901 and
Q902 (Q911 and Q913) decreases and amplitude of the output signal also decreases.

• Either the large antenna or the small antenna is selected.  — The two antennas do not oscillate at the same time.

IC901 

→

 pin@£, pin@¶, pin@¡ 

→

 to the large antenna

IC901 

→

 pin@ª, pin#¡, pin#§ 

→

 to the small antenna

* The large antenna oscillates normally to read the data from the memory chip when a video cassette is brought closer to the video

cassette recorder.

• The antenna (small) oscillates in the following condition:

* When the TITLE key is pressed in the modes other than Cassette-In/REC END/REC, the system enters the EDIT menu.
* During Title Search/Blank Search
* Cassette IN 

→

 Pressing TITLE 

→

 Another tape is brought closer 

→

 Pressing TITLE.

pin

@¡

 (pin

#§

)

Fig. 2-4

When the modulation signal is present, the 
modulation signal goes to the "L" level.

pin

3

 

CN900 

Fig. 2-5