"Jeff" wrote in message
. com...

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
I have modelled it in MMANA (my cage is similar to 'fat dipole2.maa') and it
looks feasible. The cage resonant frequency drops a tad but the extension
after the trap, modelled with a 3mm wire, does resonant nicely. This allows
me to add an extra band somewhat below the normal low limit of the cage
dipole. My modelling still shows a reasonable bandwidth for the main cage
dipole but I suspect the trap will have some complex effects above and below
resonance. I will have to try it to see how much it affects it will have.
It will be easy to clip a trap to each end of the main dipole for the tests.

73 de Dick G4BBH