Radio Reception - GMC 2007 Envoy Denali Owner's Manual

Radio Reception

You may experience frequency interference and
static during normal radio reception if items
such as cellphone chargers, vehicle convenience
accessories, and external electronic devices
are plugged into the accessory power outlet.
If there is interference or static, unplug the item
from the accessory power outlet.
AM
The range for most AM stations is greater than for
FM, especially at night. The longer range can cause
station frequencies to interfere with each other.
For better radio reception, most AM radio stations
boosts the power levels during the day, and then
reduce these levels during the night. Static can also
occur when things like storms and power lines
interfere with radio reception. When this happens,
try reducing the treble on your radio.
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FM Stereo
FM stereo gives the best sound, but FM signals
reach only about 10 to 40 miles (16 to 65 km).
Tall buildings or hills can interfere with FM signals,
causing the sound to fade in and out.
XM™ Satellite Radio Service
XM™ Satellite Radio Service gives digital radio
reception from coast-to-coast in the 48 contiguous
United States, and in Canada. Just as with FM,
tall buildings or hills can interfere with satellite
radio signals, causing the sound to fade in and out.
In addition, traveling or standing under heavy
foliage, bridges, garages, or tunnels can cause
loss of the XM™ signal for a period of time.
The radio could display NO XM SIGNAL to indicate
interference.