Magnum Dynalab MD-209 - Manual (Page 15)

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RECEPTION TECHNIQUES
Antenna Cabling:
The lead-in cable from the antenna is often the weakest link in the FM system. Some
time spent on selection and matching will yield dramatic results when it comes to
noise reduction in weak signals.
A good grade of 75 ohm coaxial cable will provide very sufficient signal passage,
along with effective shielding against interference. Without effective shielding your
coaxial cable can in fact become an antenna in itself. There are different grades of
75 ohm cable, there is RG 59/U (Suitable for 50 feet and less) and RG 6. RG 6 is
the better of the two and should be used in runs of 50 feet or more. The RG 6 has
quad shielding and 50 % less losses than RG 59/U.
The key to maximizing the efficiency of the system is insuring that all connections are
clean and tight, silicon grease on outdoor connections will insure good performance
over a long period of time. If you splice either cable, make sure that exactly the
same type of cable is used.
Types of Antennas:
Multi-element Yagi - This is a unidirectional antenna capable of pulling in very distant
stations due to its high gain, the higher the gain the better. These types of antennas
are very directional and should be used with a rotor to get the maximum benefit of
the antenna. The directional feature helps eliminate multi-path problems by allowing
only the signal from the direction that the antenna is facing to be picked up by the
antenna and not the signals that come from a different direction.
Magnum Dynalab offers two Yagi antennae, the MD 6 FM or MD 10 FM
Vertical ½ Wave - This design offers ease of installation and operation. This type of
antenna is omni-directional, which means that it picks up stations coming from all
directions. No rotor is required to pull in stations from behind or the side. This
design also gathers more of the FM signal from the air, offering superior fidelity over
that of a standard bi-directional antenna. It also gives 2.5 dB gain to the signal
strength over that of a standard dipole.
If multi-path is a reception problem try laying the antenna down in the horizontal
plane rather than the vertical plane. This type of antenna can be used indoors or
outdoors, but regardless of whether it is installed indoors or outdoors the higher
that you can put it the better it will perform.
Magnum Dynalab offers the MD ST-2, an excellent vertical ½ wave antenna
Folded Di-Pole - This is the most common and simplest of all antennas, most people
are familiar with the 79 cent piece of wire you received with most electronics gear