The SPA5 Processor-Amplifier

The SPA5 can be supplied with your choice of either 3.1 MHz or 3.3 MHz carrier frequency oscillators.

Complete technical details and setup information for the SPA5 is available in the Instruction Manual.

(Oops! The photo has an error. It seems that I forgot to attach the driver transistor and its heat sink to the SPA5 before I took the photo.
You can see where the driver transistor is supposed to be if you look at the photo of the PA3 amplifier.)

Overview -

The SPA5 is a combination system which includes an audio signal processor an automatic level controller, a 3.10 MHz carrier oscillator/modulator/RF driver stage, and high-power switch-mode RF power amplifier.

The SPA5 can produce output power levels of up to 500 watts peak power or 300 watts average power when connected to a 50 Ohm load. The power output of the SPA5 is adjustable from zero to full power simply by adjusting the DC power supply voltage connected to the SPA5’s RF power amplifier.

The SPA5 is fully automatic, and accurately tracks any variations in the input signal frequency or amplitude to correctly maintain a nominal 50% duty cycle modulated RF output signal. Diagnostic LED’s are built into the SPA5 for verification of proper operation and as an aid in troubleshooting, should that be necessary.

The audio processor circuitry of the SPA5 has been designed to accept a sine wave frequency generated by a computer. Most computer sound systems are unable to reproduce high quality square waves above just a few hundred Hz. Most computers with standard sound cards will not produce sine wave signals correctly above 19,000 Hz. These problems can make computer sound cards virtually unusable when square wave modulated Rife systems are used. However, computers with sound reproduction systems using high sample rate hardware are capable of reproducing sine waves of much higher frequencies, in some cases, up to 90 KHz or more. These systems will also work very well with the SPA5.

The inability to generate sharp-edged square waves is a serious problem. In order to generate the higher frequency harmonic energy required for a Rife plasma tube system to work properly, the leading and trailing edges of the square wave must be “sharp,” that is, the square wave must have very fast rise and fall times.

To solve this problem, the SPA5 has been designed to accept sine wave audio frequencies within the frequency range that the computer sound card can generate. The SPA5 then doubles those frequencies and converts them to clean square waves before using the square wave to modulate the 3.1 MHz carrier wave.

By doubling the input frequency, modulation frequencies of 38,000 Hz or higher (depending on the sound card) may be obtained using a standard computer sound card as the signal source. This allows the 3.1 MHz carrier to be modulated across the entire 500 to 25,000 Hz frequency range required for the 3.1 MHz Rife sweep. A frequency generator program such as Ken Uzzell’s FreX16 or FreXmcm is optimal for driving the SPA5. See: http://spectrotek.com/frex/

The SPA5 audio frequency doubling system allows the researcher to be able to properly implement the 3.1 or 3.3 MHz Rife Sweep protocol as outlined in the document posted at: http://rifevideos.com/dr_rife_and_philip_hoylands_3.3mhz_sweep.html

SPECIFICATIONS:

DC Power Supply Input:

SPA5 Logic circuits: +19 to +22 volts DC filtered and regulated, at 1.75 Ampere maximum. The actual current required varies with the modulation duty cycle.
SPA5 RF output amplifier: +12 to +190 volts DC maximum, filtered and regulated at 2.5 amperes maximum. The actual current required varies with the RF power output and the modulation duty cycle.

Input “A” - Audio Signal Limits:

Sine wave audio signal from a computer, or other frequency source.
Signal level must be within the limits of 1.0 to 6.0 volts peak-to-peak.
5 to 120,000 Hz when using a +HV voltage of 170 volt or less.
5 to 75,000 Hz when using a +HV voltage of 190 volt or less.

Input “A” – Duty Cycle Control:

For an input signal level between 1.0 and 6.0 volts, the modulation duty cycle of the RF output will remain within the limits of 48 to 50%.
The modulation duty cycle of the modulated RF output is constant when the frequency of the input signal is between 5 to 120,000 Hz.

Input “B” - Audio Signal Limits:

Square wave with a 50% duty cycle.
The input signal level must be within the limits of 0 to 6.0 volts peak-to-peak.
1 to 400,000 Hz when using a +HV voltage of 170 volt or less.
1 to 150,000 Hz when using a +HV voltage of 190 volt or less.

Carrier Frequency:

3.1MHz (standard) or 3.3 MHz (alternate) or custom. The carrier frequency must be specified at time of order. The carrier frequency may be changed by the user. This is done by replacing the plug-in standard frequency oscillator module with a custom module of a different frequency.
Customer requested frequencies in the range of 2.7 MHz to 3.7 MHz are available on special order.

RF Power Output:

The SPA5 will produce up to 500 watts peak power, or 250 watts average power as measured across a 50-ohm load when the carrier is modulated by a 50% duty cycle square wave.