Theory Of Operation - Command Technologies COMMANDER HF-2500 Manual

Theory Of Operation

The Commander HF-2500\HF-2500 MAGNUM uses a pair of C.P.I.
Eimac 3CPX800A7 ceramic/metal triodes in a class AB2 grounded grid
configuration. Nominal drive power of 50 to 60 watts will deliver 1500
watts of clean RF output power. This amplifier will operate on the
following amateur bands: 160,80,40,20,17, and 15 meters. (12 and 10
meters with authorized modification) . File copy of proper license is
required for these instructions. Operation of this amplifier on the 11
meter (citizen band) is not possible as this unit employs RF chokes
with series resonance within this band. Attempted operation will cause
serious damage that will not be covered under warranty.
Metering Functions
The Commander HF-2500\HF-2500 MAGNUM has two illuminated
panel meters. The Grid Current meter provides a continuous reading
of the 3CPX800-A7 grid current. The meter scale is 2 MA per division,
the range is 0 to 200 MA. DO NOT EXCEED 100 MA OF GRID
CURRENT. DAMAGE TO YOUR TUBES COULD RESULT. Under
typical operating conditions the grid current will be 30-50 MA . Plate
voltage and Plate current are shown on the second meter. A function
switch on the front panel switches the meter from plate voltage to plate
current. Plate current is shown on the top scale. Each division is 30
MA, and full scale is 1,500 MA. The typical plate current under
nominal rated output (1500 Watts) should range from 1000 MA to 1200
MA on the HF-2500, and 700 MA to 800 MA on the HF-2500
MAGNUM. with an absolute maximum of 1500MA. for SSB. Plate
voltage is indicated on the bottom scale with each division reflecting
.06 KV. The scale has a range from 0-3.0 KV (0-3.5 KV HF-2500
MAGNUM). The nominal no-load plate voltage on the HF-2500 should
read approximately 2,600 volts, with 3,400 volts on the HF-2500
MAGNUM. Plate voltage under nominal full load should read
approximately 2,300 volts (3,200 volts HF-2500 MAGNUM).