It started when the dummyload was too small for a job. It's for 40 mtrs.
But making it is barely possible. It should have a Zo of 50 ohms ? And what
about the Q factor ? Looking on my swr meter it gets better when i put my
hands near it and at a very small C rate but still in the red.
Anyone ?

An LC circuit won't make a good dummy load.

A "pure" LC circuit is lossless... both the L and the C are pure
reactances, and neither will (or can) dissipate any power.

In practice, you could make an LC series circuit which would be 50
ohms resistive at a single frequency... you'd use a really lousy
inductor (one wound with many turns of small wire) which has a pretty
significant DC resistance. The series C would be just enough to tune
out (resonate) the inductance at the frequency you're going to be
using it with. The inductor's ESR at this frequency is going to be
higher than its DC resistance, due to skin effect and other loss
phenomena.

The resulting circuit would *not* be 50 ohms resistive at other
frequencies. It'll have a capacitive reactance at lower frequencies
and an inductive reactance at higher frequencies.

Seems like an expensive and annoying way to make a dummy load. Unless
you've got other requirements you haven't mentioned, I'd suggest just
making a halfway-decent dummy load from a bunch of noninductive
resistors (e.g. in series-parallel) mounted on some sort of heatsink.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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