[G0KYA] A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m

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G0KYA's Amateur Radio Blog

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A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m

Posted: 27 Jan 2017 02:40 PM PST
http://g0kya.blogspot.com/2017/01/a-shortened-multi-band-end-fed-half.html

The 80-10m EFHW
This is a shortened multiband antenna, about 23m long, for 80m-10m that
offers low SWR (1.3:1) on 80m and 40m, and below 3:1 on 20, 15 and 10m. The
antenna has almost 300kHz bandwidth on 80m between 3:1 SWR points. But
performance is down about 8-12db on a dipole on 80m.

This design came from attempts to find an 80m antenna that could fit into a
small space. This was because Norfolk Amateur Radio Club likes to take part
in the 80m Club Championship (we won in 2016), but many members don't have
enough space for a full size (132ft) dipole or the 100-102 feet needed for
a G5RV or W5GI antenna.

This antenna lets you get on to 80m in a horizontal distance of about 12m
(40ft) when used as an inverted sloper with the apex at 8m, although you'll
be down a couple of S points on a dipole. But if the other station is
59+20dB, you'll be about 59 +5 or 10db, so all is not lost!
I take little credit for this as it was outlined in PD7MAA's and IK0IXI's
blogs after extensive work on the antenna in the Netherlands. However,
there was little on their blogs in terms of its performance or SWR
characteristics. Hence this write-up.
Don't forget I have a designs for high performance monoband and multiband
verticals for HF that are proven performers.
Download the 80-10m EFHW antenna guide