WhitakerAudio AM/FM Stereo Tuner 2012, Assembly & User Manual, Page: 140 / 166

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WhitakerAudio
The simplest antenna is a folded dipole made of 300
Ω
twin-lead as illustrated in Figure 8.2.
The “T” part of this type of antenna should be hung so that it is as straight as possible, with no
twist in the lead. Frequently the lead is stapled, nailed, or taped to a piece of wood or heavy
cardboard to reinforce it. This type antenna is directional, so it should be oriented for best
reception and placed as high as possible. This type is not recommended for long-range reception.
Most VHF TV antennas make excellent FM antennas and are frequently used for this purpose.
Best possible operation will be obtained using one of the commercially available antennas
designed especially for FM operation and installing it as high above the ground as conveniently
possible. Conventional TV antenna grounding and lightning protection devices should be used for
safe operation.
For systems using coaxial cable, use the appropriate matching transformer to convert from the
75
Ω
cable to the 300
Ω
input of the tuner. Note that mast-mounted preamplifiers are available for
some outdoor FM antennas. They may provide improved reception on weak signals. They may
also, however, overload on strong local signals. It is recommended that a preamplifier be used
only if necessary for good reception of the desired signals.
8.2.1 Tuning Guidelines
Proper tuning is essential if full enjoyment of FM programming is to be obtained. Mis-tuning will
result in excessive distortion and noise. When listening to weak stations, only one response will
Figure 8.2 Simple FM dipole antenna.