20kW FM transmitter
General information
The series belongs to the High Power VHF product family of FM Radio Transmitters fully solid state technology air cooled.
The 20 kW family operating in the Band II for FM stereo sound broadcasting.
20kW FM transmitter
General characteristics
TX 20000 is composed by:
Logic and combiner
Exciter 500W (driver)
N. 8 modules configurated in slave from 2K5w output power each
Logic and combiner
It is the heart of the apparatus, it checkes and combines the slaves modules of power in order to all three amplifiers (slaves) work in the same matter to guarantee the same signal of amplitude and phase.
In this way the umbalancing power is reduced at the minimum.
This control is realized by a board with micro processor and it is necessary also to control the LCD display and the knob.
The same board is installed on the power modules.
It is possible to see all the parameters of the TX 8000 using the knob.
In this way, you can see from the display the direct power, the reflected power and entering in the diagnostic menu you can see the environment temperature, the headsink termperature and the input power.
In the rear panel of TX 20Kw combiner there are the following connectors:
- 3 1/8" output power connector
- N. 8 7/16" input power connectors. These connectors have to be connected at the output power of each module.
- N. 8 N connectors. These connectors are the driver output and they have to be connected at each input power connectors modules.
- N. 1 N connector. It is the input power from the exciter.
N. 1 SUB-D25 connector. This connector is a control bus for the TX 8000.
CHARACTERISTICS:
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Frequency range: |
87.5 - 108 MHz |
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Low pass filter: |
band with 87.5 MHz - 108 MHz |
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corrosion |
All the mecanical part are yellow alluminium |
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Misure point |
Monitor RF |
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Visualized parameters |
More than 50 visualized parameters on display LCD |
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setting parameters operation |
From the frontal panel through encoders and LCD |
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CPU |
Yes |
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Redundance power supply |
yes |
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Redundance fan Ventole |
yes |
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Transistors |
ICEFET |
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Type of transistors |
St microelettronics SD2942 |
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Connectors |
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Output RF connectors |
3+ 1/8" |
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Input rf connectors |
N |
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Audio input chanel L/R |
XLR female |
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Imput connector MPX |
BNC female |
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Connector SCA |
BNC female |
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RF Block |
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General stability of the output power |
+/-0,1 dB |
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Output Impe |
50? |
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Armonich suppression |
> 70 dB |
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Spurie suppression |
> 80 dB |
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Imput impedance |
50 ohm |
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Gain |
18dB |
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Threshold of ROS Software |
11 % output power |
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Threshold of ROS fast hardware |
11 % |
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AM resid |
0,10% |
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AM resid sincron |
0,20% |
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Efficency |
65% tip. |
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Different temperature of the air in entrance / gone out |
20 °C |
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Type of cooling |
Forced air |
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ENVIRONMENTAL CONDITIONS |
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Temperature (oper) |
0 - +45 °C |
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Temperature (non ope) |
-20 - +70 °C |
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Umidity (oper) |
95% a 40 °C |
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Umidity(non oper) |
90% a 65 °C |
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Altitudine (oper) |
>4600 met |
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Altitudine (non oper) |
>15000 met |
20kW FM transmitter
