Yaesu FTDX9000D - DATA MANAGEMENT Operation Manual page 99

SSB/AM M T
ODE
Class-A operation provides a significant improvement in transmitter distortion suppression. During Class-A,
the 3rd-order IMD products are typically suppressed 50 dB, while the 5th- and higher-order IMD products (that
can cause "splatter" that interferes with others) will typically be suppressed 70 dB or more.
If you are using a linear amplifier such as the VL-1000, the low distortion produced by the FT
transmitter means that these intermodulation distortion products will not exist to be amplified by your linear.
High-Power 200-Watt Final Amplifier Stage
The final amplifier stage of the FT
devices operating at 50 Volts. The push-pull configuration provides low distortion along with high power
output. The 120 mm thermostatically-controlled cooling fan directs forced air across the heat sink, should the
heat sink temperature exceed the temperature that will trigger the thermostat.
FT 9000D O
DX PERATION
( L
RANSMISSION OW
L - D
OW ISTORTION
Continuous adjustment of the Bias
Level between Class-A and Class-AB
is possible.
Class-AB
Class-AB and Class-A Operating Principle
Q Q Q Q Q
UICK UICK UICK UICK UICK
9000D utilizes a pair of ST Micro Electronics Corp. SD2931 MOSFET
DX
M
ANUAL
- D CLASS-A O
ISTORTION
CLASS-A O
PERATION
Class-A
P P P P P
OINT OINT OINT OINT OINT
)
PERATION
Input
9000D's
DX
Page 97