Henry Radio 3K Classic Mark II Operating And Maintenance Manual page 5

SECTION 2. INTRODUCTION
The 3K Classic Mark II, 3K Classic X Mark II, and the 5K. Classic are a fam-
ily of high quality, console model, one-stage linear RF amplifiers designed
around the rugged and economical Eimac
3CX1200A7 ceramic triode.
All three
models
employ
a grounded grid circuit to insure simplicity of design and
years of reliable operation.
The amplifiers are completely self contained
and use only the highest quality RF and DC c omponents available today.
The 3F; Classic Mark II uses a single tube offering about 13 dB of gain (the
output is about 20 times the drive power) making it drive easily with lower
power solid-state exciters. This model uses a moderate duty power supply
for operation in the United States. FCC regulations require that units
supplied in the United States can not operate on the 28 MHz band.
The 3f; Classic X Mark II is an export, military, or industrial version of
the 3K Classii. Mark II. This model mates a heavy duty power-, supply with
the ';k: Classic RF deck to coffer a high gain amplifier with the reliability
of an industrial type power supply.
The 5K Classic uses two 3CX120OA7 in conjunction with a special high v-31t--
age,
heavy duty power supply for a minimum of 3500 watts PEP output in mil-
itary or commercial applications. This amplifier is available for sale
only to military, export, or industrial users.
These are a family of amplifiers because they are all designed around the
same
basic RF deck design which employs a unique rotary tank inductor not
found in any other line of production amplifiers.
All the models can be
used for SSB, CW, RTTY, or AM operation on any frequency between 3.5 and 30
MHz (subject to United States restrictions on 28 MHz).
Please read the instruction manual carefully before operating the new
equipment.
Power amplifiers can be damaged by operation out of resonance.
The amplifiers are shipped with the tubes installed,
sr, no assembly is re-
quired before you can operate the equipment.
CAUTION:
There are dangerously high voltages present inside
the amplifier when the power
switch is turned
ON. Never
remove any covers when the amplifier is plugged in or turned
on!
Always exercise extreme caution when servicing any amp-
lifier.
THE VOLTAGES FROM THE HIGH VOLTAGE POWER SUPPLY CAN
BE LETHAL!
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