RFCAST – MT100. Rev. 2: 06-12-04
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Input
110
Vac
or
220
+/-
15%
(manually
switched)
Output 28
to
30
Vdc
I max
10 A operating; 15 A short circuit
Efficiency
85%
typ.
Isolation
4
KV
(In/out
or
In/GND)
Weight (Typ.)
1500 g
Size
(WxHxD) 120x80x200
3.2
MT100 DC/DC Power Supply
The MT100 uses a DC/DC converter. It provides a voltage of 15V to the exciter and power
to the fan circuits. Below, the technical specifications:
Vdc Input
20 up to 53 Vdc
Output
1
15
Vdc/1.5
A
Output
2
28
Vdc/3
A
3.3
FM Stereo Exciter
The exciter is RFCast model OME-1T. The declared nominal RF output power is 1 Watt;
this signal arrives to the RF final stage through the RF protection circuit. All the input
connections are arranged on the front panel. Please refer to the annex datasheet at the
back of this manual for more detailed specifications and for operational settings.
3.4
MT100 RF Control Circuit
The RF input circuit has 3 main functions:
1)
RF power control
2)
RF protection
3)
Measurement/status indication
RF Power Control.
A pin diode attenuator controls the RF input power coming from the
exciter (OME-1T). RT3 trimmer may manually control this attenuator located on the
internal control panel, in order to adjust for the output power requirement. The AGC
control regulates the power, manually set, versus frequency and/or temperature changes.
Moreover, the input attenuator includes a soft start, activated at the switching on or after
any RF protection intervention. To access RT3 the operator engineer will need to remove
the transmitter top cover.
When the MT100 works at a very high temperature and/or high reflected output power, a
derating circuit is provided to decrease the output power in order to allow the equipment
on function at a reduced power.
