The local hardware store offers broomsticks made of aluminum for a price of next to nothing. Some months ago, I picked two of those up, the plan was to build a loaded dipole of sort... I never really got to use them for anything interesting yet, until today, an idea came along.
This could be a blue-print for things to come:
Looking a the TW-antennae, this is what I can see: a centre loaded short vertical dipole with end-capacitors. The company offers manuals for download, I could not resist doing so ;-) The only difference between the various models seems the centre loading box, the mechanical structure appears common to all models.
And here the broomstick come into the game. I figure, a similar structure can be build using 6 of those above mentioned aluminum broomsticks. Electrical insulation, like for the centre piece of the connection to a stand, can easily be done using PVC-plumbing parts.
For ease of manufacturing, I would probably go for a modular setup inside the loading box, meaning, exchangable sets of coils for different frequencies. The box holding the loading network will therefore be picket slightly oversized with a skrew-on lid. I recall to have seen boxed for outdoor electrical installations having such properties.
Not sure when to start with this project, I will however post pictures, as soon as there is something to show.