Sony D-FS18 Marketing Operating Instructions Manual page 13

To improve broadcast reception
For FM, extend the headphones/earphones cord.
Headphones
For AM, reorient the CD player itself.
Note
Keep the headphones connected to the i jack of the CD player. The headphones cord works as the FM
antenna.
If it is hard to hear the FM broadcast
Set the LOCAL/DX switch to "LOCAL" using a
pointed material.
Under the normal conditions, set it to "DX."
When listening to the radio on batteries
If you connect the external power source plug to the DC IN 4.5 V jack of your CD player, the CD
player will turn off. Turn it on by pressing RADIO ON•BAND to continue listening to it.
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