User's Manual

EXHIBIT 2 PAGE 5 OF 17
TX RX Systems Inc. Manual 7-9257 (version 1) 11/03/00 Page 5
same amount but will come out at power levels that
are related to their respective input level by the
gain specification. Signal leveling is not an
intended function of a signal booster. Amplifier
stages used in this signal booster system may be
damaged by excessively strong input signal levels.
The system is equipped with Output Leveling Cir-
cuitry (OLC) to protect the amplifiers and reduce
spurious signals. It is interesting to note that the
total power for the multicarrier condition is always
less than the maximum single carrier rating. As the
number of carriers increases, the difference
between the single carrier maximum and the total
power of all carriers grows even greater.
Linear power amplifiers (Class-A operation) are
used in this application in contrast to the highly effi-
cient Class-C power amplifiers used in the output
stages of most FM land mobile transmitters. Linear
amplifiers are biased for a relatively high continu-
ous DC current drain that does not change with
changing RF drive levels. Class-A amplifiers gener-
ally have the lowest efficiency of the various ampli-
fier types, typically in the range of 25 - 33%. Their
biggest advantage is faithful reproduction of the
input waveform which results in the lowest levels of
intermodulation distortion products (IM) of all the
classes of amplifiers. The generation of IM distor-
tion is a serious design consideration when two or
more channels are simultaneously present in the
same amplifier stage.
Filtering is used at the input and output of the sig-
nal path to help suppress any IM products that may
be inadvertently generated. Signals that exceed
the maximum input rating may either damage the
signal booster or cause it to generate intermodula-
tion products that exceed the maximum allowed by
the FCC or other regulatory agency.
Note About Output Power Ratings
A single maximum output power rating does not
apply to broadband signal boosters because the
linear amplifiers (Class A) used in them may have
to process multiple simultaneous signals. Under
these conditions, the questions of power rating
becomes more complex.
When more than one signal is amplified, a number
of spurious signals will also appear in the amplified
output. They are referred to as intermodulation dis-
tortion products, more commonly called IM. These
spurious products would not be present in a per-
fectly linear amplifier but as in all things, something
short of perfection is realized. Accepted industry
practice is to use the Third Order Intercept Point
specification of a signal booster to predict the level
of IM products. The intercept point is derived from
the measurement of an amplifiers 1 dB compres-
sion point.
INSTALLATION
The layout of the signal distribution system will be
the prime factor in determining the mounting loca-
tion of the signal booster enclosure. However,
safety and serviceability are also key consider-
ations. The unit should be located where it cannot
be tampered with by unauthorized personnel yet is
easily accessible to service personnel using trou-
ble shooting test equipment such as digital multim-
eters and spectrum analyzers. Also consider the
weight and size of the unit should it become
detached from its mounting surfaces for any rea-
son.
Very little is required to install this signal booster.
The unit should be bolted in its permanent position
using lag bolts or other suitable fasteners. Make
sure there is an unobstructed airflow over the
external heatsink. Safety and serviceability are key
considerations. The signal booster cabinet will stay
warm during normal operation so in the interest of
equipment longevity, avoid locations that will
expose the cabinet to direct sun or areas where the
temperature is continually elevated.
The signal booster is designed to be powered from
120 VAC and a conduit entry box is provided at the
bottom of the enclosure for bringing the AC line into
the cabinet. AC line connections should be made in
accordance with local electrical and building codes.
Connection of RF to the unit is made via “N” female
connectors located on top of the cabinet. These
connectors are individually labeled “Input” and
“Output”. Care should be used when making con-
nections to these ports to insure the correct
antenna cable is connected to its corresponding
input / output port or the system will not work. The
use of high quality connectors with gold center pins
is advised. Flexible jumper cables made of high
quality coax are also acceptable for connecting to
rigid cable sections.
CAUTIONARY NOTE
The following cautions are not intended to frighten
the user but have been added to make you aware