The M.O.P.A. is now 20 Megahertz capable with a variable built in carrier frequency of 2.2 to 3.8 MHz and is a 1930s/1950s replica. When connected to the GB-4000 it is capable of outputting 8 Frequencies Simultaneously.

The M.O.P.A. or Master Oscillator Power Amplifier uses the gas filled tube radiant method of outputting frequencies from 1 to 20 million Hertz. Many people ask what are the benefits of the M.O.P.A. over the SR-4 amplifier? First: The M.O.P.A. uses the gas filled tube method. The gas filled tube method allows for a greater power output of 190 watts compared to the SR-4's 15 watts output. Second: the M.O.P.A., for the first time since the 1930's, allows for the use of high frequencies directly output through the gas filled tube. This has been a long sought after feature that many have been asking for. If you are wanting to use the more powerful, versatile 1930's/1950's radiant method, then the M.O.P.A. amplifier is the instrument you will want to own.

When it comes to power the GB-4000, SR-4 and M.O.P.A. should be considered as good, better and best. If your budget only allows for the GB-4000 then you have one of the best frequency generators you can purchase. If your buget allows for the GB-4000 and SR-4 amplifier then you move up to the next level of performance. If you can afford the GB-4000 and M.O.P.A. amplifier then you know you have the very best gas filled tube system on the market today. You also have the a system that can output both the 1930's/1950's frequencies through a gas filled tube. Only purchase what you can afford because you can always add the SR-4 or M.O.P.A. amplifier at a later date.

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The M.O.P.A. Amplifier/Oscillator Technical Specifications and Features........

  • Warranty: Two year parts and labor starting 1-1-2016. (Only exception - 90 days on internal
    812a vacuum tube).

  • Fabrication: Built by hand and tested for quality assurance.

  • Proven design: Solid state combined with vacuum tube technology used for over 80 years.

  • Amplification method: Original vacuum tube amplification.

  • Amplification voltage: High voltage (1350 volts).

  • Amplification current : Low current (20 to 240 milliamps).

  • Vacuum tube vs Solid state amplification: Modern solid state uses low voltage and
    high current designs. The M.O.P.A. uses the high voltage low current design.

  • Milliamp meter: Built in.

  • Waveform: Harmonic sine wave producing harmonic sidebands in the same manner as the
    original equipment.

  • Sine wave: Analog.

  • Frequency Counter: Built in for accurate reading of the carrier frequency.

  • Carrier frequency: Variable.

  • Built in Carrier frequency range: Approximately 2.2 MHz to about 3.8 MHz. Once the carrier frequency is set using the frequency counter the carrier frequency will stay on that carrier frequency until it is changed to a new carrier frequency.

  • Carrier frequency tuning: Variable tuning capacitor.

  • Power output: Variable average modulated power of 190 watts at 240 milliamps
    (240 Milliamps Max).

  • Frequency input method: Designed to work exclusively with the GB-4000 frequency generator
    through a BNC connection.

  • Frequency output modulation: GB-4000 audio frequencies up to 400,000 Hertz square wave
    when using the "Audio Mode" @ 100% AM modulation.

  • Maximum number of frequencies output: When connected to the GB4000 it can transmit up to 8
    frequencies simultaneously.

  • New maximum frequency range: When using the "RF Mode" 1 Hertz to 20,000,000 Hertz.

  • Gating or pulsing: 1 to 40,000 Hertz using the GB-4000.

  • Frequency delivery: Gas tube (*Sold by another company. Limited warranty applies only if
    another type of gas tube is used, then there is no warranty)

  • Gas tube ignition: Instantaneous.

  • SWR meter: None. Gas tube is connected directly to the RF tank coil requiring no SWR
    (standing wave ratio) meter. This method, unlike the SWR meter systems, delivers almost 100%
    power output to and through the plasma tube.

  • Useful range of about 30 feet when using gas tube. Due to the laws of physics there are
    limitations to gas filled tubes and metal antennas that need to be understood. Both are very
    efficient and about 100% of the energy that you put into them comes out. But for every foot
    that you move away from these antennas you lose 75% of the power they output. To illustrate
    we will use the standard loss with metal antennas as the power loss ratio for a gas tube.
    With a 200 watt output at one foot away from the gas filled tube you will only get 50 watts.  At
    two feet away you only have 12.5 watts and at 3 feet you only have 3.125 watts. Because of the
    law of physics it is important to be as close to the gas filled tube as you can get if you
    want the greatest amount of the energy that comes out of it. One to six feet distance
    away from the gas tube would be the best choice. Always the closer the better.

  • Suggested range: 1 inch to 6 feet when using gas tube. Because there is no 1 foot to 3 foot null
    zone (non-effective range) it is not necessary to stay 3 to 6 feet away from the gas tube because
    it outputs the same as the 1930's/1950's equipment that was used within 6 inches of the target area.

  • Size: Compact design - 10.5" Wide X 17" Long X 10" High.

  • Power used: Can be built for use with 110/120 volts AC or 220/240 volts AC.

  • Power usage: 350 watts. When connected to the GB-4000 375 watts.
  • Weight: 19 pounds.

    a reflector. The new reflector now makes it so the energy is focused into one general direction.
    The reflector is removable for those who want to use the gas filled tube without it.

  • PLEASE NOTE: the gas filled tube including copper collars with wires and the gas tube holder with the new reflector are sold separately from another company for $333.00 plus shipping. Your distributor can give you the phone number for that company so you can order it when you order your M.O.P.A. This gas tube is made of Pyrex and is a 2" inch round by 14" inch long Helium, Argon or Helium/Argon filled tube. It is guaranteed to handle the power output of the M.O.P.A. (*The M.O.P.A. comes with a one year warrantybut if any other plasma tube is used there is no warranty)

  • For those who already own a GB-4000, the M.O.P.A. is priced at $2495.00. This price includes shipping in the USA. (No restocking fee only shipping and repackaging fee)

  • The M.O.P.A. with GB-4000 is priced at $4220.00 and includes shipping in the USA.

    All products sold by AAA Production come with two year parts and labor warranty and free
    technical support for as long as you own your instruments. See your distributor to purchase
    a GB-4000, SR-4 amplifier or a M.O.P.A. amplifier/oscillator.


Why you would want to purchase the GB-4000 and M.O.P.A!

When the GB-4000 is combined with the M.O.P.A. the ability to run from one to eight frequencies up to 40,000 hertz through a gas filled tube is possible. No other instrument has this capability.

The M.O.P.A. is the only original vacuum tube gas filled plasma tube instrument with the ability to use a variable frequency from 1 to 20,000,000 million Hertz. It also has a variable built in carrier frequency which goes from about 2.2 to 3.8 MHz.

We use the superior high voltage low current design over the low voltage high current design.

We can usually ship within 24 to 48 hours after receiving your purchase agreement.

Both the GB-4000 and M.O.P.A. come with two year parts and labor warranty
starting 1-1-2016.

We not only give superior support but give technical support by phone for as long as you own your instrument.


RF vs EM Systems


(*EM) All gas tube instruments that are EM (electro-magnetic) do not use RF (radio frequency)
frequencies or an RF carrier frequency. They use coils to produce a high electromagnetic field to carry
the frequencies to the target. Due to the fact that they use EM to deliver the frequencies they are limited
to about 10,000 Hertz but a few go to 30,000 Hertz.
Since they do not use an RF carrier frequency it is almost impossible to determine their power output. For this reason almost none of these manufacturers list the power output of their equipment. They generally are very good instruments except for their limited frequency range. Anyone who purchases the EM type of equipment should understand that they only output low audio frequencies and have no RF carrier frequency. All the original 1920's through the 1950's instruments used RF and had a power output from about 50 to 150 watts.


GB4000 with M.O.P.A. Amplifier



M.O.P.A. Vacuum tube amplifier.
190 watts maximum output.
Built in Frequency counter.

MOPA - Home of the GB-4000 Frequency Generator.