Sony Walkman D-F201 Operating Instructions Manual page 11

To improve broadcast reception
For FM, extend the headphones/earphones cord.
For AM, reorient the CD player itself.
Note
Keep the headphones/earphones connected to the i jack of the CD player. The headphones/earphones cord
works as the FM antenna.
If it is hard to hear the FM broadcast
Set the MONO/ST switch to "MONO" using a pointed material.
The noise will be reduced but the radio will play in monaural.
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.
Headphones
or
Earphones
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