How did we get 500 watts of HF power and an AC power supply to fit in one hand? The key to our new MINI LINI is efficiency. High efficiency amplifiers allow lower utility bills, less heat and smaller size that add up to less cost overall.

Our highly innovative MINI LINI has roots that go back to 1936 when W.H. Doherty developed a high efficiency linear amplifier. Around this same time, using a highly efficient non-linear class C amplifier that modulated the plate voltage quickly became standard practice.

The next step in the process was in 1951 when Leonard Kahn published his paper titled "Envelope Elimination and Restoration." Kahn's revolutionary EER method allowed linear control of output by modulating the supply voltage to expand from AM to SSB applications. Using this method, the envelope of the input SSB signal is detected and used to modulate the amplifier supply voltage. This reconstructs the input signal. It is this EER technology that allows the MINI LINI to be so efficient and compact.

The final event that made a huge impact in the development of the MINI LINI occurred in 1975 when Nathan Sokal patented the class E amplifier. His non-linear amplifier was capable of close to 90% efficiency in practical circuits. The pairing of class E technology and the EER method is how very efficient SSB transmitters became possible. For many years, shortwave SSB broadcast transmitters of 100 KW and more have been in regular use, proving this technology to be highly reliable.

In recent years, great progress has been made in high performance, low cost components for switching power supplies. As a result, medium power PWM modulators like the one used in the MINI LINI have been simplified and costs have been reduced. The availability of reasonably priced RF rated high voltage MOSFETs has also contributed to the MINI LINI's impressive performance and reasonable price.