The 3K Ultra and 8K Ultra are a family of high quality,
console model, single stage linear RF amplifiers designed
around rugged and economical ceramic triode power tubes. All
models employ the same grounded grid design to insure
simplicity of concept and all employ conservatively rated
components to insure years of reliable operation. The
amplifiers are completely self-contained and use the highest
quality RF, DC and AC components available today. AH that is
necessary for operation is an HF transceiver, a 230 VAC AC
mains source (other voltages available) and a 50 ohm antenna
The 3K Ultra uses a single 3CX1200D7 tube offering about 11
to 13 dB of power gain (the output power is approximately 20
times the input power). This makes it easy to drive to full
output with most popular low power solid state transceivers.
It will delivery 1500 watts PEP and 1500 watts continuous
wave into a 50 ohm load. FCC regulations require that the
units supplied in the United States can not be capable of
operating above 25 MHz.
The 8K Ultra uses a single 3CX3000A7 tube ovvering about 13
dB of power gain which will deliver a minimum of 3500 watts
PEP in SSB service and 2500 watts in a CW mode. It is not
available for sale to amateur radio operators in the United
With proof of a valid amateur service license, Henry Radio
will give a United States purchaser information on how to
extend the frequency coverage to 30 MHz. All other customers
are considered export customers and their units will be
supplied with coverage through 30 MHz.
The 3K Ultra and 8K Ultra are for amateur, industrial,
scientific, medical, commercial and export users in the 1.8
through 30 MHz frequency range.
All models are designed around the same basic RF chassis
which employs a pair of unique rotary tank inductors not
found in any other line of production amplifiers. All models
can be used for AM, FM, SSB, CW RTTY or pulse operation.
Frequency coverage is instantaneously in any 200 KHz segment
between 1.8 and 30 MHz and can be tuned to any frequency
between 1.8 and 30 MHz.
The amplifiers are shipped with their tubes installed at the
factory. No tube installation is required.