The Ameritron AL-800H is a 1500 watt output linear amplifier that operates from 160 through 15 meters. The AL-800HX is the export model that operate from 160 through 10 meters. Export modification instructions are only available with proof of a valid amateur radio license. · The AL-800H uses two reliable high gain 3CX800A7 tubes. · A time-delay circuit provides a 180 second warm-up to eliminate potential damage to the tube cathodes. · A grid overload circuit quickly disables the amplifier if the grid current becomes excessive. This feature prevents excessive grid current from causing distortion or damaging the tubes or other components. · A thermal overload automatically disables the amplifier if excessive heating of the power transformer occurs. · A multi-voltage heavy-duty transformer with a unique "buck-boost" winding allows adjustment of the primary voltage to 14 different voltages centered on 115 and 230 volts. This versatile Ameritron feature allows the user to select the optimum primary voltage for maximum performance and life. · The tuning and loading controls have vernier 6:1 reduction drives for smooth tuning. Logging scales allow quick and repeatable control adjustment for rapid band changes. · The AL-800H has two illuminated cross-needle panel meters. the left meter provides a continuous reading of grid and plate currents. the right meter reads peak RF power output on one scale and Plate voltage (HV), Reflected power and SWR (REF), ALC detector voltage (ALC), and ALC adjustment level (ALC SET) on the other scales. · Heater and plat voltages are maintained using the "STBY/OPR" switch. This allows the amplifier to be conveniently bypassed for "barefoot" operation. · A front panel "ALC SET" control allows convenient adjustment of the ALC threshold. The unique ALC circuit samples the grid current and power supply voltage. · "XMT" and "OL" LED's on the front panel indicate proper operation of the amplifier. · A rear panel 12 volt auxiliary output jack provides up to 200 mA at 12 Vdc for accessories such as the ART-15 Antenna Tuner. · A step-start circuit limits the inrush current to the power supply and tube heater. This circuit extends the life of the amplifier components.