Broadcast Warehouse TX 150/300, Техническое руководство, Страница: 24 / 41

TX FM Transmitter technical manual
page 24
Installation and setup
The rear panel BNC sockets provide an easy interface to the multiplex path. You can insert an external piece of
equipment between the multiplex output of the internal stereo encoder and the modulator section.
To connect an external piece of equipment consult the external equipments documentation. It should be as easy
as configuring the transmitter as per normal and then simply setting the internal Loopthrough jumper to OFF and
taking the multiplex output to the input of the external equipment and the output of the external equipment back
into the multiplex input socket. If the external equipment is not unity gain you may have to readjust the multiplex
input gain slightly to take account for any gain differences. Most loopthrough designed equipment is unity gain to
make setup and use as simple as possible.
FREQUENCY FINE TUNE ( WARNING, ADVANCED TECHNICIANS ONLY)
While the frequency is controlled by the phase locked loop system, the stability is governed by the stability of the
reference. A quartz crystal is used for the reference for its high stability however component ageing can affect the
frequency slightly over time. The frequency can be finely adjusted via VC2. This provides a small adjustment of
the VCO frequency when locked. This will have been adjusted at factory to the correct setting and the transmitter
should remain within 1KHz of the channel required. If however the frequency does move off slightly due to com-
ponent ageing then you can adjust VC2 to trim the unmodulated carrier back onto channel. You will need a fre-
quency counter to monitor the output frequency of the un modulated transmitter when adjusting VC2.
LCD SYSTEM METERING ACCURACY
DISPLAY Measurement Accuracy
POWER SUPPLY Volts +/-1 Volt
TEMPERATURE Degrees Centigrade +/-1 Degree
PEAK DEVIATION KHz +/-1 KHz
LIMITER GAIN REDUCTION Decibels +/-1 dB
RF POWER Watts 5 %