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The PA1 Rife Plasma Tube Amplifier

Information current as of 03 December 2017

The PA1 amplifier with the HS2 heat sink.

Designed to operate with the SSQ-2F v3.21, the PA1 is a specially designed high power Rife Plasma tube amplifier.

The price of the PA1 ssembled and tested, with HS2 heat sink & fan is $175.00.

Kit version also available.

The PA1 is a high-frequency switch-mode power supply designed to convert DC power into semi-square wave pulses of energy at 3.1 MHz at power levels sufficient to drive the largest plasma tube. The PA1 has been designed so that its output matches a standard 50-ohm load impedance, making it possible to connect the output of the PA1 to a conventional antenna tuner or to the our LC31 coupler system. The PA1 with its innovative design amplifies the high quality signal from the SSQ-2F v3.21.

The PA1 is designed to be driven by the SSQ-2F v3.21. The PA1 increases the power output of the SSQ-2F v3.21 to a power level of between 300 to 500 Watts peak power depending upon the voltage of the DC power supply and the modulation duty cycle. When using a modulation duty cycle of between 0 to 100%, the PA1 will produce at least 300 Watts peak or continuous power output. For a modulation duty cycles between 1 to 50%, the PA1 can produce up to 500 Watts peak power output. These power levels are sufficient to operate even the largest plasma tubes.

Please download and read the operating manual for the PA1 before placing your order. It is important to read and understand the information about using an adequate heat sink with the PA1. Although the PA1 is physically very small, it handles a lot of power. Just as with any high power RF amplifier, a substantial heat sink is required for proper operation.

  • This is a professionally manufactured etched printed circuit board incorporating 3-ounce tin-plated copper traces, and plated-through holes. All parts are high-quality through-hole components.
  • Resistors are high stability carbon or metal film, 5% tolerance.
  • The SSQ-2F Controller Board is available assembled and fully tested, or as a do-it-yourself kit.
  • Screw terminals are provided for all connections to the PA1 - there are no wires to solder!
  • 1-year warranty against manufacturing defects.
  • Lead-free construction for ROHS compliance.


DC Power Supply Input:

1) +15 to +190 V DC at a maximum current of 3.0 amperes. Average operating current less than 2.1 amperes, depending on output power level and modulation duty cycle.

2) +150 V DC required for a nominal peak power output of 300 Watts across a 50-ohm load resistance.

3) +190 V DC required for a nominal peak power output of 500 Watts across a 50-ohm load resistance.

Output Load Impedance:

50 ohms.

Input Drive Signal:

5 Watts, semi-square wave pulse waveform at 3.1 or 3.3 MHz from the SSQ-2F v3.21.

Operating Frequency:

2.8 to 3.8 MHz. Operation outside of this frequency range may cause damage to the PA1. Nominal operating frequency is 3.1 or 3.3 MHz.

RF Power Output:

1) The PA1 will produce up to 500 watts peak power, or 250 watts average power across a 50-ohm load when the carrier is modulated by a 50% duty cycle square wave.

2) When operated at a peak power level of 300 watts, the PA1 may be operated with any duty cycle between 0 to 100%.

3) The power output of the PA1 may be adjusted by varying the DC voltage supplied to the PA1.

PA1 Output Waveforms at a Power Level of 300 Watts

The left side photos are of the PA1 output waveform across a 50-ohm dummy load.

The right side photos are of the PA1 output waveform across a Cheb 8-inch Phanotron tube.

The PA1 was coupled to the Phanotron tube using the 3.1 MHz link coil coupler.

The carrier frequency was 3.1 MHz. The modulation duty cycle was approximately 50%.

Modulation frequency 20 Hz.

Modulation frequency 2 KHz.

Modulation frequency 20 KHz.

Modulation frequency 200 KHz.


The PA1 is a high-frequency switch mode power supply module designed to furnish a square wave modulated high voltage alternating current at a frequency of approximately 3.1 MHz across a 50-ohm load impedance. If the PA1 is installed incorrectly or used improperly, it is capable of causing severe radio frequency interference. To prevent this from occurring, observe the following warnings:
  • The PA1 is to be used as a research device only, or as part of a complete system to drive a plasma tube.
  • The PA1 is not intended to be used for any form of radio transmission in any manner whatsoever.
  • The PA1 is not intended to be connected to an antenna or to any radiating element or to be used for any form of radio communications purposes in any manner whatsoever.
  • The PA1 is designed solely to be a source of power to light a plasma tube.
  • All electrical connections to the output terminals of the PA1 are to be made by the use of properly shielded 50-ohm coaxial cable capable of handling at least 500 watts at 3.1 MHz.
  • All connections are to be made in such a manner as to minimize any RF radiation from the connecting wires to the PA1.
  • The PA1 has been specifically designed to be driven by a high-level signal that is generated by the SSQ-2F v3.21 circuit board. The PA1 cannot be driven by a sine wave signal, such as from a low-powered transmitter. It is not a linear amplifier, and it will not function as such.
  • The operating frequency range of the PA1 has been restricted to a 1 MHz portion of the spectrum centered at 3.1 MHz.
Any attempt to drive the PA1 with a radio frequency source such as a CB radio transmitter, will result in either no power output from the PA1 or immediate destruction of the STW20NK50Z MOSFET in the PA1.

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This web site and all contents including pictures, text and diagrams is Copyright 2012 - 2018 by Ralph M Hartwell.