Eagle 2000 – 2kW FM Broadcasting Amplifier
User’s manual – Page 15 of 66
5.1.b
Main power supply switch and power supply relay
The main power supply switch triggers a power supply relay rated for the supply current required by the equipment. The power
supply unit is connected to this relay.
5.2
R.F. amplifier section
The first element of this section is a 3-ways Wilkinson splitter
[26] which splits the R.F. input power (30W) into three 10W outputs.
These signals are the inputs of three 800W amplifier modules
[27]. The outputs of the three amplifier modules are fed to a 3-ways
Wilkinson combiner
[28] which combines the three signals into one (this circuit includes also three unbalancing and load resistors).
The coupler output is connected to a low-pass filter
[29], which delivers the signal to the antenna output flange. In this part of the
amplifier section also includes the directional couplers
[30], which extracts the direct and reflected powers and the low-level R.F.
signals (connected to the R.F. Monitor output connector located on the front panel).
The RF input signal must be between 25 and 30W. This value doesn’t affect the output power level, because the amplifier’s
output power adjustment isn’t obtained by changing the input level (from the exciter), but adjusting the amplifier’s section gain
by means of the proper menu. This solution which guarantees a constant high efficiency, even when the user decides to set an
output power which is lower than the rated one.
Even if Eagle 2000 is able to output a (max) 2400W output power (thanks to the use of the 3x800W amplifier modules), it has a
rated output power of 2000W, a solution allowing a better reliability.
5.2.a
Connections of the R.F. amplifier section
[33]
R.F. output signal
.
[34]
R.F. input signal
.
[35]
48V
DC
power supply
– for the 800W amplifier module #3.
[36]
48V
DC
power supply
– for the 800W amplifier module #2.
[37]
Analog data bus
- 10 pole flat cable used to send to the control board the information related to: direct power, reflected power,
bias, temperature, input power.
[38]
48V
DC
power supply
– for the 800W amplifier module #1.
33
35
36
38
37
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