Kenwood SPECTRUM 350 - Manual (Page 15)

15.
Using an AM outdoor antenna (optional)
If you’re using the AM loop antenna, but reception is poor, run a vinyl-coated
wire of more than 20 feet outdoors. Do not disconnect the loop antenna.
Using an FM outdoor antenna (optional)
For the best reception and sound quality, we recommend using an outdoor
FM antenna. Since most outdoor antennas use either 75 ohm or 300 ohm
connections, your Spectrum System’s receiver provides connections for both.
Contact your local electronics dealer/installer for more information.
FM75 Ω LOOP ANTENNA
FM300 Ω
GND AM
ANTENNA