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Old November 23rd 09, 07:15 PM posted to rec.radio.amateur.antenna
Ronald Ronald is offline
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First recorded activity by RadioBanter: Nov 2009
Posts: 4
Default How can one make a dummyload from a LC circuit ?


"Dave Platt" wrote to us
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 ?

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


Not dissipate but surely radiate in a closed box!


In practice, you could make an LC series circuit which would be 50
ohms resistive at a single frequency...


Yes, it's for a single frequency. Since an antenne is also a LC-circuit
that doesn't get warm but radiates in fields.

I had it all open built so i suspect mantelwaves etc. But on paper a series
LC circuit forms a loading of a particular Zo. This statement is still right?
Lets say an input on a semiconductor p.a. stage with an LC series circuit..