Looking at the Dave Benson schematics is a good suggestion ... I would also
look at Elecraft who also has manuals online with schematics. I would also
look at the hfpacker amp (www.hfprojects.com). This was a project ran a
couple years ago to build an amp to basically take the QRP rigs in the 2.5
watt range to 30 watts or so. The design actually could do it with a watt
of drive but they put an attenuator in the front to allow flexibility with
different rigs that didn't have completely adjustable output power.

But I also have to ask the same question Tom asks. 80 is a noisy band, and
one that demands large antennas. To get past the noise you need power, and
that adds a lot of weight. Don't forget, you not only have the amp to carry
around, but you gotta carry the DC to run all this, too.

If you are line of sight, then you can go very high in frequency, but
certainly in the higher parts of the HF spectrum, the antennas are more
manageable and the bands are quieter, which means power is less of an issue.
You could even go to VHF but then the whole construction thing becomes more
challenging.

But then, if you are looking for a 100-200 mile path, then 80 probably is
the ticket, but you're going to have to constrain your playing to days when
the A index is low. Indeed, I would suspect you would want to be balooning
in the daylight - precisely when 80 is very noisy. So you better be paying
close attention to the propagation reports if you want to hear your baloon.

...

"Tom Bruhns" wrote in message
m...
Shouldn't be too difficult to come up with the brute-force answer, but
I have to ask: Why?