This exciter unit was developed to answer quite particular requirements: It consists of two different oscillators multipliers, one v.f.o. and one fixed-frequency oscillator, controlled by a crystal. The first one oscillates on a fundamental frequency in the 18 Me region. This is multiplied in consecutive stages and produces a final frequency in the 144 to 148 Me band. The crystal, however, oscillates on 12 Me. Its fundamental is multiplied in consecutive stages to produce a fixed final frequency of 144 Me. The aim of having two different oscillators, the VFO type and the crystal type, is that of using the former for brief connections (for the research of a correspondent, etc.) and the latter (having a greater frequency stability) for a normal connection. Note: Several crystals may be used, tuned on various frequencies from 12 to 12.333 Me for 144 -j- 148 Me. band, and from 12 to 12,166 Me. for 144 -T- 146 Me. band.