Sony DAV-S880 Operating Instructions Manual page 21

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If you have poor FM reception
Use a 75-ohms coaxial cable (not supplied) to connect the system to an outdoor FM antenna as shown below.
Outdoor FM antenna
Note
If you connect the system to an outdoor antenna, ground it to protect against lightning. To prevent a gas explosion,
do not connect the earth wire to a gas pipe.
System
Earth wire
(not supplied)
AM
COAXIAL
FM
75Ω
To earth
GB
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