8
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 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.
T