Steren BOS-660 Manual De Instrucciones página 10

In the bottom of the pre-amplifi er there's a switch to select 75 or
300ohms, depending of the connection (See Fig. 5).
Fig. 5
When you use coaxial cable, the output is through an F connec-
tor and must connect to the amplifi er using the connector labeled
as "To Amplifi er".
If you use a 300ohms cable, must be connected to the screws
labeled as "To Amplifi er" and the switch must be placed in
300ohms position (See Fig. 6).
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