[Amps] MRF150 based 1500 watt amp design/cost

[Dan Levin]

NB: What I know about solid state power amps can be written down on less than one sheet of paper.

That said, Motorola's engineering bulletin EB104 seems to lay out the design for a fairly clean 600 watt HF amplifier based on 4 MRF150 transistors.

Application note AR347 includes the design for a 4 way splitter and combiner that, with some modification, should be able to handle 1.5 KW.

If you married up the splitter and combiner from AR347 with four of the 600 watt amp modules from EB104, you would have an amplifier capable of running 1500 watts out while requiring only ~95 watts out from each MRF150 - right at the sweet spot of the MRF150's IM curve (about -40 db at 30 mhz).

MRF150's retail (list price) for $60 ea. from RF Parts.  The boards for the EB104 amp modules are about $65 fully populated (less power transistors) from Communications Concepts.  So we are talking about $1200 for the core electronics (still need a cabinet, control circuitry, fans, heat sink, power supply, meters, etc.).

Seems pretty reasonable for a 10-160 meter auto tune amp that should loaf at 1500 watts out and require well less than 100 watts of drive.

What am I missing?

                                ***dan, K6IF