The 3K Classic Mark II, 3K Classic X Mark II, and the 5K Classic are a family 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 components available today. The 3K 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 3K Classic X Mark II is an export, military, or industrial version of the 3K Classic Mark II. This model mates a heavy duty power supply with the 3K Classic RF deck to offer a high gain amplifier with the reliability of an industrial type power supply. The 5K Classic uses two 3CX1200A7 in conjunction with a special high voltage, heavy duty power supply for a minimum of 3500 watts PEP output in military 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).