Dave D'Epagnier wrote:
> I'm intrigued by the prospect of not having to fuss with tuning every
> time I change frequencies and especially not having to obnoxiously
> tune
> up on the air.
> So, I'm looking into designing and building a 1-1.5kw broadband solid
> state amplifier that needs no tuning, and considering using Motorola
You probably know this, but Motorola have produced lots of application
notes on using their devices for this sort of application. Eg AN758, 'A
Two Stage 1kW Solid-State Linear Amplifier'. This uses 8xMRF428 + 2 x
MRF427A's.
Most, if not all the earlier application notes (including AN768) can be
found in 'RF Application Reports', HB215/D, which is a soft-backed book
over 500 pages long. You can (or at least could) get this free by
ordering from Motorola's web site. A gold-mine of information. Some of
the earlier editions of this book are even better than the late ones -
hence I hang on to my old editions.
See http://www.maneapc.demon.co.uk/motorola/ for UK hams. I think
www.motorola.com is better for the US.
To me, the effort of building a tube amp, and tuning it, seems almost
trivial in comparison to building these solid state ones. I also expect
the solid state amp will cost a lot more than a tube amp built from
surplus tubes - your chances of getting enough surplus
transistosr/modules must be almost nil. However, that's a personal
opinion.
G8WRB
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