A nice piece of homebrew inspiration worth sharing: fellow amateur YG1BQO has designed and built a shortened rotary dipole for the 40m band, aimed squarely at operators working with limited space.
The design uses loading coils partway along each element to electrically “shorten” the antenna while keeping it resonant around 7.100 MHz — bringing the total span down to roughly 12 metres, considerably shorter than a full-size 40m dipole. Key elements of the build include a central boom with mast clamp for rotation, a 1:1 balun at the feed point, and a pair of hand-wound loading coils (around 43 turns on a 25mm former) built from enamelled copper wire on PVC formers.
As with most shortened/loaded antenna designs, final tuning comes down to trimming the outer whip length in small increments until the SWR dip lands where you want it.
A great example of the kind of practical, space-conscious antenna engineering that keeps HF accessible even without a large garden — the kind of homebrew project worth discussing at one of our sessions if you’re working with a similarly tight footprint.
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