On 1/19/11 12:36 PM, email@example.com wrote:
> Hi, thanks for the comment
> In the antenna I described, the antenna is ordinary wire, and the feed is
> ordinary coax.
> I'm planning on RG-6 actually (copper shield).
> The antenna I described doesn't have anything to do with bazooka designs?
> It's just a dipole with a coupled parasitic.
> If you're saying a single wire with LC match can have same bandwidth and
> lower loss, I guess I find that hard to believe?
> Am I missing a loss calculation in open sleeve designs?
When you say open sleeve, do you basically mean something where the
apparent diameter of the conductor is larger (e.g. like cage dipoles,
bowties, biconicals, and to a lesser extent, fan dipoles)?
In general, you can get pretty low loss in a lumped inductor, because
you can use larger diameter wire and you can get more inductance for a
given length of wire (i.e. a single turn has more L than a straight
wire, and 2 turns has 4 times the inductance of a single turn, with only
twice the resistance). You can wind inductors with ribbons, tubes, etc,
I think that Rick's comment is right on.. Doing a lumped network
(because it's higher Q, lower loss) tends to be more challenging to
construct and measure. A "distributed loading" scheme has more loss and
tends to be less construction picky.
For a builder with NO measurement tools other than a tape measure and
the reflected power meter in their rig, a "build it to these dimensions"
design has a lot of appeal (I know.. I've been there.. )
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