Lostgallifreyan wrote:
wrote in :
The rhombic was a big deal in it's day back when huge, empty areas were
readily available and better antennas had not yet been invented.
I like apples and strawberries, but I'll not go into it. 
I had a very quick look at log-periodic antennas before I sleep. That looks
like a much more practical notion to me. I guess practical DIY might still be
limited to shorter wavelengths, but it looks like a neat, compact and solid
antenna design, ideally suited to anyone with some accurate tooling and a
need for directivity combined with a relatively broad bandwith reducing need
for adjustments. Would it be a contender against a tuned magnetic loop for a
beginner's experiment?
Like all things in life it is a trade off of various things.
The accuracy requirement, at HF anyway, is not that bad and there are
LOTS of plans for DIY log periodic antennas out there.
Upside: Basically frequency independant (over a range), all metal
construction, can directly match 50 Ohms, and gain can be increased
by increasing the number of elements and making it longer.
Downside: A high gain antenna can be quite large, require a lot of
expensive aluminum, be quite heavy and like any beam needs a tower
and a rotor.
Since it is truely frequency independant, for certain uses, like military
that could be operating on any frequency, it is an almost ideal solution.
For hams that are constrained to bands, something like a hex beam
might be a more economical solution.
Your call.
--
Jim Pennino