TEM A07A2200S, Maintenance And Installation Manual

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A07A2200S
4.6.12 PAGE UP for a new screen shot :
In this case it’s possible to insert the pre-emphasis or to set the transmitter from mono to stereo and
vice versa.
The pre-emphasis value (50 or 75µs) is switched by a jumper placed on the rear window of the rack.
The pre-emphasis operates on the LEFT and RIGHT channels only.
By choosing the STEREO option, the LEFT and RIGHT channels are encoded with the stereo
subcarrier addition, from which it’s possible to get a synchronism in the IN/OUT rear connector
(1Vpp sine wave).
On the opposite, if an external stereophonic source is already available, the LEFT and RIGHT
inputs must be kept free by using the MPX input (rear BNC); in this case
the transmitter must be
set to MONO even if the transmission is STEREOPHONIC.
When the transmission is monophonic, if one enters by the two LEFT and RIGHT channels, the
transmitter is modulated at the nominal value; if only one channel is available, this one must enter at
the same time both in the LEFT and RIGHT channel inputs, so
they must be put in parallel
otherwise the deviation would be half of the nominal one.
4.6.13 By entering PAGE UP the following screen shot appears :
Here it’s possible to see the frequency deviation value and the input signal values.
When the composite signal is chosen (addition of all the modulating signals), the numerical and
visual indication appearing is the frequency modulation expressed in KHz while on the LEFT,
RIGHT MPX signals, the level is measured and displayed as value 100 when it matches the
nominal value.
The indication states the peak and the chosen measurement will be flashing displayed on the LCD.
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