On Feb 24, 4:37 am, "Dave" wrote:
"K7ITM" wrote in message

...

Anyone have any practical LPY (log-periodic Yagi) antenna designs they
care to share? Something with about 4% or 5% bandwidth in the VHF/low
UHF range should do well--the element diameters should be appropriate
for scaling the design to my frequencies of interest. 10dBi or so
gain is probably fine.

Cheers,
Tom

define "log period yagi"??? ramsey has a line of products that they call
'log periodic and yagi' pcb antennas that has apparently been smushed into
"LPY" as the prefix to their part numbers... but 'Yagi' antennas are one
thing, and 'Log Periodic Dipole Array' antennas are something else. The
only place they cross practically that i have seen is the use of a log
periodic section feed section in between yagi style tuned parasitic elements
to give a wider bandwidth feed point... in this case it is usually just 2 or
3 elements worth of lpda feeding the yagi which i have always considered
just a way to add buzzwords to your antenna design description.

Yes, that's the design. I have data on a couple that suggest a pretty
"flat" gain across a modest range of frequencies, with a relatively
abrupt drop in gain outside that range. Googling got me to the
printed circuit antennas (I guess for wireless networks and the like),
but they aren't suitable to scale for what I want to do--too many
things different about them (flat elements on a dielectric substrate,
versus round elements in air).

Cheers,
Tom