The AL-811 is a grounded grid linear amplifier
developed by Ameritron using low cost 811A power
triodes. It operates in class AB2 for SSB and CW.
1. Fast Warm Up Time: The 811A tubes take
approximately 3 seconds to warm-up.
2. Long Tube Life: The 811A tubes are long life,
reliable transmitting tubes. 811A tubes offer
rugged, reliable operation even on RTTY and
3. Tuned Input: A Pi-Network tuned input
matches the 811A tubes to 50 ohm exciters.
4. Two Illuminated Panel Meters: The AL-811
has two illuminated panel meters. The Grid
Current meter provides a continuous reading of
the 811A grid current to indicate proper loading
of the amplifier. The other meter switches
between high Voltage (HV) and Plate Current
5. Safety Interlock: Removes AC from the unit
when the cover is removed. Never attempt to
defeat this switch.
6. Operate/Standby Switch: Used to remove the
amplifier from the RF line while filament and
plate voltages are maintained for "barefoot"
7. XMT Indicator LED: Provides a front panel
indication of proper amplifier keying by the
exciter during operation.
8. ALC Voltage: The drive level is detected to
provide a negative control voltage for the exciter.
ALC prevents overdriving of the linear and
reduces distortion from excessive drive power.