1
Safegua
rds
2
Terms and
Warranty
3
Principl
e o
f
Operati
on
4
Ins
talla
tion
5
Operati
on
6
C
ont
rol Syst
em
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RF Componen
ts
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Power
Supp
ly
9
Maintenan
ce
10
Troubleshoo
ting
Principle of Operation
The internal FM exciter found inside FM transmitter enclosures accepts analog,
digital or MPX audio signals and modulates them onto an FM carrier. The analog
signal can be either mono or stereo (both included as standard), while the digital
inputs are accepted on AES3, S/PDIF optical (Toslink), or S/PDIF coaxial inputs.
Also included on the Exciter circuit board are amplifier stages to increase the
modulated level from a few dBm up to several watts.
The RF power amplifier is designed to take a modulated FM carrier from the
Exciter (typically less than 30-watts depending on transmitter power level), and
amplifies the carrier to a level that is suitable for transmission through an
antenna, cavity, or alternative load. The power amplifier feeds this load through
an inline wattmeter and transmission line. For broadcast and over-the-air
amplifier systems, the pattern of the antenna then dictates the range and
coverage area.
The amplification is accomplished by one or many amplifier pallets internal to the
power amplifier system. If there is more than one amplifier pallet stage, then the
first pallet acts as a driver feeding Intermediate Power Amplifiers (IPAs) and/or
final stage pallets. If multiple final pallets are required, then a splitter and
combiner are also required before and after the final stages.
Technalogix manufactures FM amplifiers and transmission systems suitable for
88.0 to 108.0 MHz. Custom frequencies are available upon request if you require
carriers outside this range, including audio for VHF applications and other unique
requirements.
The RF amplifiers utilize readily available RF components wherever possible,
thus enhancing the serviceability of the equipment. The amplifier modules are
stable for high reliability and long service life and feature ultra linear amplification
and individual channel RF output filtering, unless ordered otherwise.
The Block Diagram is included with the Quickstart package to illustrate the
specific component flow of the RF amplifier system and to provide specific
configuration and model information.
