Fisher RS-2010 - Page 9

ANTENNAS
FM ANTENNAS (Refer also to INSTALLING section)
The following paragraphs provide instructions for replacing
the FM-dipole antenna with other indoor or outloor anten¬
nas to suit local receiving conditions:
REDUCING MULTIPATH INTERFERENCE
In some strong-signal localities, pronounced signal reflections
from surrounding buildings, towers, or hills may cause multi-
path interference. (This phenomenon is similar to “ghosts”
in TV pictures and can cause distortion, “fuzziness”, and
reduced left-right separation in FM-stereo broadcasts.)
In such cases, it may be necessary to replace the dipole an¬
tenna with an indoor “rabbit-ears” or telescoping-dipole an¬
tenna that can be rotated for best reception of the desired
signal and maximum rejection of the unwanted reflections.
(This type of antenna is available at most electronic-parts
dealers.)
Disconnect the dipole antenna from the FM ANT. terminals
and connect the rabbit-ears antenna in its place, making sure
that the antenna lugs or wires do not touch each other, ad¬
jacent terminals, or the receiver chassis. Tune in several FM
stations and rotate the antenna for best reception of each.
IMPROVING FRINGE-AREA RECEPTION AND
REDUCING ELECTRICAL INTERFERENCE
In weak-signal “fringe” areas an outdoor antenna may be nec¬
essary, especially for effective, noise-free FM-stereo recep¬
tion. If you already have an outdoor VHF television antenna,
and know that FM signals in your area come from the same
general direction as the TV signals, the antenna may prove
suitable for FM reception as well. To test it, disconnect the
dipole antenna from the FM ANT. terminals and connect the
TV antenna in its place, making sure that the antenna lugs
or wires do not touch each other, adjacent terminals, or
the receiver chassis. If the results are satisfactory, obtain a
two-set antenna coupler so that you can operate both the TV
set and the receiver from the antenna simultaneously.
If reception is still unsatisfactory, you may have to connect an
outdoor antenna designed specifically for FM. In medium-
fringe areas (up to 40 miles from stations), where most signals
come from the same general direction, a folded dipole with
reflector should provide good results. If signals come from
several different directions, an omnidirectional antenna such
as a cross-dipole, “turnstile”, or “S” will eliminate the
necessity for an antenna rotator. For deep fringe areas 50
miles or more from stations, a high-gain “Yagi” array or Log-
Periodic antenna is recommended. These antennas are quite
directional however, and if station signals come from several
directions, you will probably require a remote-control antenna
rotator.
If you live near a busy thoroughfare or industrial area, and
the outdoor antenna is connected to the set with conven¬
tional 300-ohm twin-lead, interference from automotive
ignition systems or electrical machinery may radiate into the
long lead-in, causing objectionable noises throughout the
FM band. In such cases, replace the conventional lead-in
with shielded 7 5-ohm cable (available at your local Hi-Fi
store). Connect the lead-in’s two signal conductors to the
receiver’s 75-ohm FM ANT. terminals in the manner, shown
in the INSTALLING section.
AM ANTENNAS
If AM reception is marred because you live in a steel-frame
building, or if you want to supplement the built-in AM an¬
tenna for improved reception of weaker stations, connect
10 to 20 feet of insulated, flexible, single-conductor wire to
the EXT AM ANT. terminal. Keep this wire away from all
speaker, audio, and power cables. Run the wire in a straight
line along a non-metallic baseboard or under a rug. In some
cases, reception may be further improved by draping the
wire out a window or by connecting it to an outdoor whip
or rod antenna.
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