Do It Yourself

RF amplifier

6m band 300W RF power amplifier

            The 50MHz magic band will be on peak propagation at the last and this years. I am now currently use the homemade dipole and FT-736 + homemade 100W linear amplifier for the DX. Because of my dipole antenna is no gain, I feel that I always can listen the DX stations but cannot call back them at the same time. In this cause, I think I need to build a new higher power linear amplifier. I saw a 6m 450W RF power amplifier in UKSMG homepage. Two MRF448 were used in that amplifier. But in Hong Kong, by the license, the TX power on 6m should be less than 26dBW 400W ERP. So I am just use one of the Motorola MRF 448 RF power transistor in my project. Delete the splitter, combiner and half of the amplifier from the original circuit.

Full view

Front view	Back view

Inside 1	Inside 2

Inside 3	Inside 4

Inside 5

The main PCB

    Schematic Diagram in UKSMG homepage

    PCB Layout in PDF format

    Data sheet for MRF448 in PDF format

Specifications and Details :