User's Manual

7
CAUTION
The amplifier must be installed in such a way that free flow of hot air from the tube is
allowed. The amplifier must not be installed in a constrained surrounding (i.e. tight shelves
etc.). During long time operation ventilation grid can reach high temperature. Do not touch it!
The amplifier must be properly grounded during operation
.
During operation the amplifier must be installed in such a way that the rear side remains
accessible.
The amplifier is an A category product. In a household it can influence other electric
appliances. In such cases the user is to take proper actions to mitigate this disturbance.
Read this manual carefully. Fallow all of instructions during installation and operation to
avoid damage to the amplifier not covered by manufacturer´s warranty! Do not attempt to
perform any change of hardware or software!
3. GENERAL DESCRIPTION
3.1. HF part
his amplifier is using a ceramic tetrode FU-728F in a grounded-cathode circuit (input into
control grids). The OM2000A+ 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 grids, 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.
T
WARNING! The installation of this device must be compliant with CFR 47. 1.1310 of the Federal
Communications Commission rules. Refer to guidance in OET Bulletin 65, Supplement B for
more information.