1.4. Features
•Easy operation. The plate-load True Resistance Indicator (TRI) is an ACOM innovation that provides
quick and precise tuning, typically in less than 10 seconds. The auto-operate function will return the
amplifier to the OPERATE mode automatically after each protection trip, saving time and avoiding
manual switching.
•No tuner needed. No external antenna tuner is required as long as the antenna VSWR is 3:1 or lower.
The amplifier will perform the functions of an antenna tuner, enabling you to change antennas faster
and use them over wide frequency ranges.
•A durable amplifier. This amplifier is both user-friendly and self-monitoring. It is designed to safely
withstand up to 240W of reflected power, up to 100 milliseconds of drive spikes (RF "tails" after a PTT
or KEY release), and even operator tuning errors. It is also capable of operating at more than half its
designed output power at only 75% of nominal line (mains) voltage. Because it can tolerate deep
voltage drops (down to zero for 10 milliseconds) and 15% line voltage spikes, it is particularly suited
for use in portable environments, such as field days and DXpeditions.
•LED bar-graph display. The upper LED bar-graph always reads peak forward power (except for the
service functions) while the lower LED bar-graph is for the reflected power. LED warning indicators are
provided for abnormal conditions of grid 1, grid 2, and plate parameters.
•Antenna selection. Two antenna outputs are selectable on the front panel of the amplifier.
•Efficient tuning. Antenna matching can be achieved in less than 10 seconds and at a quarter of
nominal output power, which produces lower risk of interference to other stations and greater safety
to the amplifier components.
•Transceiver-independent. The amplifier operates without special signaling from the transceiver. It
needs only "ground on TX" and 60W RF drive power to operate at full output power.
•Input matching. Broadband input matching circuitry offers excellent loading characteristics for the
driving transceiver, from 1.8MHz to 30MHz.
•Single tube operation. A single Svetlana 4CX800A (GU74B) high-performance ceramic-metal tetrode
with plate dissipation of 800W (forced air cooling, grid-driven) is used for maximum efficiency.
•Permanent monitoring and protection of the plate and grids currents. The Bias Optimizer minimizes
heat dissipated by the tube, assuring tube longevity.
•High voltage protection. Design of the high-voltage power supply eliminates the danger of turn-on
transients affecting sensitive devices connected to the same line (mains) circuit. Moreover, the
amplifier can be configured to accommodate any of 8 nominal line voltages between 100 and 240V, 50
or 60Hz.
•Band inclusion. The amplifier can be shipped with 10 and 12-meter capability disabled as required by
the Federal Communications Commission (FCC), for United States users. Contact your dealer about
enabling those bands.
