OM POWER OM2500 A-F, Инструкция по эксплуатации

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3. GENERAL DESCRIPTION
3.1. HF part
In this amplifier a tetrode FU-728F is used in a grounded-cathode circuit (input into control
grid). This amplifier achieves excellent linearity by the voltage stabilization of the control
grid bias and the screen voltage. The power input is given to the control grid, using a
broadband input circuit with an input impedance of 50 Ohms. This adaptable input circuitry
ensures a good input SWR (better
than 1.5:1) on all amateur bands.
The output of the amplifier is a Pi-L circuit. The ceramic capacitor for TUNE and LOAD are
divided. This enables the amplifier to be tuned exactly and makes it possible to easily return
to the previously set positions after band changes.
Top view on the opened OM2500A-F
Tetrode
FU-728F PWR meter Blower Switch-on board
Output Pi-L Circuit Tuning capacitor Power supply board
Subpanel