The POWER MOS FET VRF150MP runs at 50 V in push-pull. You can obtain a stable output of 200 W on all bands. You achieve superior IMD properties by pursuing bias and matching conditions in order to fully exploit the FET attributes. Further, you can realize KENWOOD's distinctive tone by amplifying the clean modulated signal produced by DSP with an amplifier that exhibits excellent linearity.
The built-in automatic antenna tuner is a preset type that covers amateur band frequencies ranging from 160m~6m, and is completely operable during receive. The tuner is capable of rapid QSY based on instantaneous band change, using a relay system known for high-speed operations.
The relays, capacitors, and inductors use large-sized components that are able to bear the 200 W output.
Cooling is very important to obtain a stable output of 200 W. Heat dissipation efficiency is increased in the TS-990S through a large fin-type aluminum heat sink. An independent variable-speed fan is provided for the switching power supply, final unit, and antenna tuner, cooling each unit with a sufficient air supply. The switching power supply and the final unit have twin cooling fans. Noise is reduced by controlling the fan speed according to the temperature.
Thermal Simulation Example
To dissipate the heat of the 200 W final, we used swage fins instead of the conventional extruded aluminum fins. Using CAE analysis, we designed the optimal fin shape and size for heat dissipation.
