www.SteamPoweredRadio.Com
of a good
FM
tuner. For the lowest noise, minimum distor-
tion, and largest choice of well-received broadcasts,
an
outdoor antenna is the best complement to a fine tuner.
A roof-mounted antenna has three fundamental ad-
vantages. First, its large size yields better sensitivity (pulling
in
a stronger signal from the desired station) and a narrower
directional pattern for more effective rejection of multipath
reflections arriving from other directions. Second, its loca-
tion on a roof or tall mast places
it
above many sources of
interference-passing
cars and buses, other buildings, etc.
Third, the strength of received
FM
signals
is
directly pro-
portional to the height of any antenna above the ground.
If you already have
an
outdoor television antenna, using
a splitter to extract
FM
signals from
it
may produce excellent
results. However, many TV antennas are deliberately de-
signed to
be
relatively weak at
FM
frequencies
in
order to
minimize potential interference with TV signals at nearby
frequencies (Channel 6
in
the U.S.).
You
may be able to use
. a splitter to extract
FM
signals from
an
apartment building's
master TV antenna system, but usually this yields poor
results because many master antenna systems have
"traps" to stop
FM
signals.
The best choice
is
a directional FM-only antenna,
mounted as high above ground as
is
practical, and sepa-
rated by at least two meters
(7
feet) from other antennas,
vertically and horizontally.
If
desired stations are located
in
different directions (more than 90 degrees apart), the
antenna should
be
mounted on a rotor for aiming. Brand
names of good
FM
antennas
in
the
U.S
. include Jerrold,
Finco, Wineguard, Antennacraft, and Archer (Radio Shack).
Use shielded lead-in cable rather than plain "twin-lead"
wire, both to minimize interference and to preserve strong
signals during years of weathering. The cable may be either
75
-ohm coaxial or a shielded 300-ohm type. Disconnect
any indoor antenna before connecting the cable from the
outdoor antenna.
If
you are using a 75-ohm coaxial antenna cable that
lacks a connector, you may attach its center conductor to
either 300V antenna terminal and connect the cable shield to
the ground (G) antenna terminal. This unbalanced connec-
tion provides the required 75V impedance for the cable. But
the 300V antenna terminals are connected to the
FM tuner
circuit through
an
internal "balun" transformer. The 75V
coaxial socket
is
wired directly to the tuner circuit, bypassing
the balun transformer, so to obtain the best possible sensitiv-
ity, the coaxial cable should be connected to the 75V socket.
If
you install an outdoor antenna yourself, observe these
important CAUTIONS:
1.
Do
not mount the antenna close to electric power
lines. Plan the installation so that the antenna mast cannot
accidentally touch power lines, either while you are installing
it
or later.
2. Include a lightning arrestor
in
the installation, to
protect both yourself and the tuner circuit from potential
danger during electrical storms.
6.
AM ROD ANTENNA
The ferrite
rod
antenna provides effective reception
of local medium-wavelength
AM
radio stations. The rod is
mounted on a pivot. For best reception, swing
it
away from
the metal chassis of the receiver.
7.
PHONO GROUND
If your turntable
is
equipped with a grounding wire
(usually a green wire terminating
in
a U-shaped spade lug),
connect
it
to this terminal.
Turn
the thumb-nut counter-
clockwise, place the spade lug under the nut, and tighten
the thumb-nut clockwise to secure the lug.
If
the grounding
wire has
no
spade lug, strip off 1 cm of insulation to expose
the bare wire, twist the wire strands tightly together, insert
5
the wire though the small hole
in
the shaft of the Ground
terminal, and tighten the thumb-nut to fasten the wire
in
place.
If
you encounter a persistent low-level hum or buzz
in
the sound, connect a wire from the Ground terminal to a true
earth-ground, i.e. a copper-plated rod driven several feet into
the earth. A substitute electrical ground may also prove
effective: a cold water pipe, a steam radiator, or the third
hole of a modern electrical wall socket.
In
some cases
reversing the orientation of the AC power plug
in
the wall
socket may yield a reduction
in
hum level.
8. PHONO INPUT
Plug the signal cables from your turntable into these
jacks.
If
the cables or plugs are color-coded, refer to your
turntable's instruction manual to learn which cable or plug
is
for the Left channel (upper jack) and which for the Right
(lower jack). Be careful to insert each plug fully into the
socket so that the plug's metal skirt fits tightly over the
exterior of the socket. If necessary, crimp the plug's metal
skirt slightly so as to obtain a tight fit with the socket.
9.
MM/MC SELECTOR
This switch sets the input sensitivity and gain of the
phono preamplifier circuit. Set it according to the output level
of your phono cartridge. Set the switch at
MM for cartridges
of the moving magnet, induced magnet, moving flux, and
moving iron (variable reluctance) types, and for "high-output"
moving-coil pickups, i.e., those with a rated output of
1.0
mV
or greater. If your cartridge
is
a low-output moving-coil pickup
(with a rated output of less than 1.0 mV), set the switch
at
MC.
Here is another way to determine the preferred setting of
the MM/MC switch. Begin by setting it to MM. After you have
completed the installation and wiring of the system, play a
record. With the front-panel LOW LEVEL button OUT you
should obtain a satisfyingly loud volume level with a VOL-
UME control setting between 9 o'clock and 3 o'clock.
If
you
have to turn up the VOLUME control beyond 3 o'clock to get
adequately loud sound, turn the VOLUME back down and
re-set the MM/MC switch to MC.
10.
CD INPUT
Connect the audio signal cables from a digital Compact
Disc player to these jacks. The input signal will be fed to the
Volume control before reaching any active circuitry, so the
amplifier's circuits cannot
be
overloaded by high-level sig-
nals from the digital player.
If you don't have a CD player, any other line-level signal
source (such as a spare tape deck) may
be
connected to the
CD input.
11.
AUX INPUT
These auxiliary jacks are for any "line level" signal
source, such as a spare tape deck, the audio line output
from a videocassette or videodisc player, or a television
sound tuner.
12.
TAPE INPUT/OUTPUT
The tape connections may
be
used with recorders of
all types: cassette, micro-cassette, open-reel, digital, etc.
To
make recordings, connect a stereo patch cord from the
amplifier's TAPE OUT (REC) jacks to the recorder's LINE
IN
jacks (not to its microphone inputs).
To
play back tapes,
connect a stereo patch cord from the recorder's LINE OUT
jacks to the amplifier's TAPE
IN
(PLAY) jacks.
The TAPE REC/PLAY jacks may be used for connecting
a signal processing accessory instead of a tape recorder.
Examples of such accessories include a dynamic range
processor, a dynamic noise filter, a DBX disc decoder, or
any other device whose operation depends on the setting
of a signal threshold. Connect a patch cord from the TAPE
OUT (REC) jacks to the processor's inputs, and another
To Next Page
Loading...
Need help?
General
