NAD 712 Manual Del Usuario página 9

above many sources of interference — passing cars
and buses, other buildings, etc. – and the strength of
received FM signals is directly proportional to the
height of antenna above ground.
If you already have an outdoor television antenna,
using a splitter to extract FM signals from it may pro-
duce excellent results. However, many TV antennas
are designed to be relatively weak at FM frequencies.
You could use a splitter to extract FM signals from an
apartment building's master antenna system, but this
will yield poor results if the system has a "trap" to stop
FM signals.
The best choice is a directional FM-only antenna,
mounted as high above ground as is practical, and
separated by at least two meters (7 feet) vertically or
horizontally from any other antenna. If desired sta-
tions 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 from
the receiver before connecting the outdoor antenna.
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 fall into contact with 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 poten-
tial danger during electrical storms.
USING A LONG-WIRE ANTENNA FOR
BETTER AM (MEDIUM-WAVE) RECEPTION
To improve reception of distant AM stations, attach
a long-wire outdoor antenna to the AM terminal. A
"long-wire" antenna is a straight wire whose length
may be anything from a few feet up to about 100 feet
(30 meters), mounted parallel to the earth and as high
as is convenient.
The effectiveness of a long-wire antenna may be
improved by connecting a second wire from the
Ground (G) terminal to a true earth-ground, i.e. a cop-
per-plated rod driven several feet into the earth. A
substitute electrical ground, such as a cold water
pipe, may also prove effective.
MAKING SURE THAT YOUR SPEAKERS ARE
IN PHASE
Stereo speakers should operate in phase with each
other in order to provide a good stereo image and to
reinforce rather than cancel each other's output at low
frequencies. If your speakers are easily moved, their
phasing can easily be checked. Make the connec-
tions to both speakers, place the speakers
face-to-face only a few inches apart, play some
music, and listen. Then swap the connection of the
two wires at the back of ONE speaker, and listen
again. The connection which produces the fullest,
boomiest bass output is the correct one. Connect the
wires securely to the speaker terminals, being careful
not to leave any loose strands of wire that might touch
the wrong terminal and create a partial short-circuit.
Then move the speakers to their intended locations.
If the speakers cannot easily be set face-to-face,
phasing must rely on the "polarity" of the connecting
wires. Note that the SPEAKERS terminals on the
receiver are colour coded: in each channel the red
terminal has positive "+" polarity and the black termi-
nal is negative "–". The terminals at the rear of the
speakers are also marked for polarity, either via red
and black connectors or by labels: "+", 1, or 8 ohms
for positive, "–", 0, or G for negative. As a general rule
the positive (red) terminal on the amplifier should be
connected to the positive terminal of the speaker, in
each channel.
To facilitate this, the two conductors comprising the
speaker wire in each channel are different, either in
the colour of the wire itself (copper vs. silver) or in the
presence of a small ridge or rib pattern on the insula-
tion of one conductor. Use this pattern to establish
consistent wiring to both speakers of a stereo pair.
Thus if you connect the copper coloured wire (or
ribbed insulation) to the red receiver terminal in the
Left channel, do the same in the Right channel. At the
other end of the wire, if you connect the copper
coloured wire (or the ribbed insulation) to the red or
positive terminal on the left-channel speaker, do the
same at the right-channel speaker.
If a second pair of speakers are located near the
first pair in the same room and will be played simulta-
neously, then they must be correctly phased with
respect to the first pair as well as with each other. But
if the second pair of speakers are located away from
the first pair (in another room, for example) or will not
be played at the same time as the first pair, then their
phasing need not be match that of the first pair. As
with any stereo speakers, the second pair still must
be in phase with each other.
COPYING TAPE RECORDINGS
If you want to copy a recording from one tape deck
to another, the recorder that will make the copy
should be connected to the TAPE 1 IN/OUT jacks as
described in the section on rear-panel connections.
The machine containing the original "source" tape
should be connected to the TAPE 2 IN/OUT jacks.
Use the RECORD switch to select the TAPE 1 input
signal for recording. If you also use the LISTEN but-
tons on the receiver (or the Input Select buttons on
the remote control) to select TAPE 1, you can hear
the signal from the source deck.
If you engage the TAPE 1 MONITOR button, you
will hear the same signal after it has passed through
the copying recorder's electronics. (In some recorders
the input signal is heard only when the Record button
is pressed.) Adjust the recording level on the copying
recorder, and make the recording.
You can use the same front-panel settings to
reverse the direction of copying, i.e. to copy from a
source tape on TAPE 1 to a blank tape on TAPE 2.
When you press TAPE 1 on the input selector, the
playback signal from Tape 1 is automatically fed to
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