Topband: wideband inv-L

[Michael Tope]

----- Original Message -----
From: "DAVID CUTHBERT" <DAVIDNNAN at MSN.COM>

>
> I did experiment with shunt T-lines and LC networks for further extending
the bandwidth (using WinSmith). I do see the double VSWR hump and I do see a
modest increase in bandwidth. However, the slightest loss really extends the
bandwidth and I suspect this is what many find. I think we will avoid this
route.
>

Yes, but the loss in the lumped LC compensating network used for
generating the double VSWR hump is not the primary mechanism
responsible for extending the impedance bandwidth. In principle,
these losses can be minimized to an insignificant level without any
significant bandwidth penalty if good enough components are
available. The LC approach and the small loss in efficiency (0.5 to
1.0dB) in many instances may represent a good tradeoff when
compared to the mechanical complexity of a cage or multiwire
structure.

73 de Mike, W4EF........................................................