The Hentenna was originally designed during the 1970’s in Japan by JE1DEU / JH1FCZ/ JH1YST etal.
Why use a hentenna
- Good performance
- 2.5-3 dBd gain
- Low angle radiation, good for DXing
- Easy to make
- Wide Bandwidth
* Total performance is equivalent to 2-3 element Yagi-uda antenna, Wide band width
How does it work?
The outside loop acts as a 1 and 1/3λ Loop. the smaller loop acts as a matching loop (many make the loop adjustable).
The Vertical Long loop has more gain than a square loop as well as lower impedance.
When mounted vertically it emits horizontal radiation and when mounted horizontal it emits vertical radiation!
To adjust the SWR move the matching rectangle in small steps until you have achieved the SWR you are looking for.
in Fig 1. a MMana-Gal plot for SWR whilst in Fig . we ave a Radiated far field Plot
I have made these for a number of bands and still use it on 4m. All of mine have been made using a wooden frame with dowels to support the wire following the pattern of the antenna (2 vertical pieces and three horizontal) at the feed point you can either direct feed the coax straight to the antenna or install an appropriate Connector to connect your feeder (I prefer direct feed with lots of weatherproofing.)
I have used these antennas with great success on
* Oddly the 2m Hentenna also works on 70cm without any alterations, do the math it doesn’t add up but it sure as heck works, and with a low SWR Too, making building a 70cm Hentenna Pointless!