"
I have been looking at the properties of a cage or fat dipole. This is
efficient and has a wide bandwidth. But what happens if a trap is added

Hi Dick,

It would seem to be a contradiction in sizes (the coil and cap have to
be much smaller), but then when I think of cage antennas, I see:
http://home.comcast.net/~kb7qhc/ante.../Cage/cage.htm

The point of the cage is to not need adornments.

73's
Richard Clark, KB7QHC

Since the elements of a cage dipole usually come to a point at both ends
(the feed and the far end for attachment of a support) I can see no problem
in physically adding a trap.

Above the trap cut-off frequency the extensions will have little effect on
the performance. At lower frequencies where you will effectively have a
dipole element with a fat portion and then a thinner bit at the end , it
should work ok but you may need some modelling to see exactly what happens
to the bandwidth.

73
Jeff