TEM A07A2200S, Maintenance And Installation Manual

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A07A2200S
4.4 Ground loops
Sometimes connecting various ground sockets having different potentials may produce some
unwanted loops, which may create hum in the modulation: in this case it is essential to firstly
identify the origin of these currents, which normally spring from the antenna ground, mains
supply ground or from the input low frequency signals ground.
If the inconvenience can not be removed, the balanced input of the two channels LEFT and RIGHT
can be used, thus obtaining common mode noise rejection of 40dB approximately.
All the inputs and outputs are protected by diodes against the electrostatic discharges and they are
provided with filters against the RF noise.
4.5 Transmitter power up
After making sure about the proper earth socket connection, correct power supply and
connection of the load on the antenna output, the equipment can be switched on.
If there is the first switching on, problems of wrong setting can’t occur since the transmitter
contains some standard values and
the output power will be set to 10W , in order to avoid any
problem of interference or driving for possible following amplifiers. The set values will be
displayed and changed according to your need before the RF power is emitted from the transmitter.
The equipment is provided with a memory which holds all settings even when the electric supply is
off, however it is recommended to set the power at 10 W when uninstalling the transmitter itself to
avoid any problem in case of a new setting up.
REMEMBER THE PASSWORD !
To enter the setting menu, knowing the password is mandatory. It’s a four digits number written on
the transmitter delivery document. Should it be forgotten, it will be possible to perform the set up
by setting the Z2 jumper placed on the board DLCD (vertical board placed behind the rear panel) on
the soldering side; the jumper is easy to identify through the close capture: PASSWORD ON/OFF.
In this case, this operation must be performed with the equipment switched off and it requires also
the opening of the top cover which, at ended operation, must be closed again with all its screws; it is
essential to use a proper cross point screwdriver.
4.6 Transmitter settings
4.6.1 At the switching on, the display will glow giving for few seconds the
following screen shot
380 221 R02 Pag. 15