"John Sandin" wrote in message
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I guess it would have been easier and even cheaper to buy a kit. But
I had fun building this, and I guess I'll have almost as much fun
rebuilding it.

One of the wonderful things about amateur radio is that there are so many
facets to explore. Each of us finds his own favorites, but in my mind,
there are few things in life as fun as building and operating your own
equipment.

Your low pass filter leaps out at me. Typically, the coil windings are
spread out over 80% of the toroid, rather than 20%. If, in fact, this was
the intent of the low pass filter design, then your inductances could be
quite a way off. Not only would this change the cutoff frequency of your
LPF (raising it most probably, so not likely the direct cause of low
output), but it would also change the impedance the transmitter sees. (I'm
leaping to the conclusion here that the LPF is between the transmitter and
the antenna). What this means is that the transmitter isn't seeing 50 ohms
even if your antenna is resonant. This would result in the final heating,
and could also favor the parasitics that I suspect we have going on here.

As you explore what's going on here, keep in mind that these things aren't
magic, what they do is always goverened by the laws of physics. Validate by
measurement that what you think is happening is, in fact, what is going on.
You really don't need a ton of test equipment. Granted, lacking lots of
gear, each measurement can be a bit of a project in itself, but once you
have a DMM and have built an RF probe (about a buck's worth of parts), you
can make pretty much any measurement if you think it through.

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