problem with amplifier/receiver

[huttonrose14]

not sure if this is the right forum - new to macrumours - i just bought
a used amp/receiver - am not getting any sound when i switch to FM -
i do get sound when i switch to AM - the FM antenna that came with
the receiver has two connectors atttached to a female cable input -
i spliced the cable into my existing cable i have coming into the house
and get a strong AM signal - cannot figure out why i can't get an FM
signal

 

[ChrisA]

...the FM antenna that came with
the receiver has two connectors atttached to a female cable input -
i spliced the cable into my existing cable i have coming into the house
and get a strong AM signal - cannot figure out why i can't get an FM
signal

You are going to have to supply some diagrams or pictures. More details. Did you really "slice" a cable? There are about a zillion ways to mess that process up.

Typically AM radio if any external antenna is used at all is just a simple wire whereas FM antenna are connected using either 75 ohm coax or 300 ohm twinlead. The best way to connect all this depends on exactly what you have and the distances involved. But in any case I'd not expect AM and FM to share an antenna or an antenna lead.