Carver TX-11b Manual page 8

Grounding
FM
While grounding an outdoor antenna is vitally important, there's
normally no need to ground the tuner itself. But with safety and
possibly reduced interference in mind, you may want to ground the
tuner chassis. If so, run a heavy (12-gauge or heavier copper/alum.)
wire from the tuner to a metal cold water pipe. You'll have to check
to make sure the metal pipe is grounded; PVC (plastic) pipes are
somtimes run in from the water main to the house, then metal pipes
are used within the house. NEVER attach a ground wire to a gas pipe,
either for your components, or antenna. The best grounding scheme
is a ground rod driven several feet into the earth. See the chapter on
ANTENNAS for information on installing a ground rod.
Antenna Terminals
AM
Two AM antennas have been provided with your TX-11 b.
Experimentation will tell you which antenna works best for your
location. See the chapter on ANTENNAS for further informaton.
AM Loop Antenna
The first is a high performance, noise-free AM loop antenna held on
the rear panel with a snap-in hinge. Swivel it out for best reception.
You may also remove the antenna from its hinge and attach it to a
nearby wall. The length of the antenna cord is 2 feet and should not
be pulled tight.
Securely connect the loop antenna leads to the AM and GND
terminals.
AM Wire Antenna
The second AM antenna is a wire that attaches to the AM terminal of
the TX-11 b. This wire will increase AM sensitivity, and we highly
recommend its use for AM stereo reception.
You can either connect directly to your local Cable Television
System for FM (consult your Cable Operator) using coaxial
cable, or use the supplied 75/300 ohm adaptor and dipole
ribbon antenna. Caution should be used when connecting your
Preamp/Tunerto an external outside TV/FM antenna. See Notice
located in the front of this manual. If uncertain, please refer to
qualified personnel. If hum occurs when using the 75 ohm
terminal, install a 75/300 ohm balanced transformer to the
coaxial cable, and reconnect to the supplied 300 ohm to 75
ohm adapter to break the ground loop that is causing the
offending hum.
A commercial cable company, as a matter of procedure and policy,
most often connects a tuner using the 300 n antenna terminals. Few
tuners have provisions for direct connection to 750 feeds. Normally,
a feedline from a FM trap is connected with a matching transformer
(75 ft to 300 ft) to the 300 ft antenna terminals by the cable company
installer. Their transformers come with spade lugs on the leads, and
are the same type used to terminate a regular TV cable at the VHF
antenna terminals of a TV set. NOTE: It isn't legal to "do-it-yourself
and tap into a commercial cable TV system without telling the cable
company. So, don't do it... even if you know how!
If you can talk the installer into connecting the cable feed directly to
the 75 ft terminals, ask to have a female to female coaxial connector
inserted between the main feed from the FM trap and a shorter piece
of cable connected to the tuner. This provides an easy disconnect
for the cable lead-in, without unhooking it at the TX-11 b's rear panel.
This is an especially good idea for those who will use 75 ft coaxial
cable with their own antenna systems for quick disconnect during
electrical storms.
GND AM
I I
oo
750
•ANTENNA