RadCom February 2016, Vol. 92, No. 2

59 / 100

February 2016 59
Technical
worth knowing though that while experimenting
with this 5 band antenna I had no problems at
all with RF in the shack or problems with RF
detection in the microphone of my rig. I tested
the antenna with only 5m of RG58 coax and
100W, with the transformer box hanging a foot
outside my shack window.
I now use a single FT240-43 core for the
1:1 current balun with 12 windings of RG58
coaxial cable as found on the website by Steve,
G3TXQ [2] .
Summary
These end-fed antennas are relatively easy
to build and the 5 band version, only about
24m long, is a nice small antenna. The 3-band
version for 40, 20 and 10m is only about 12m
long so it is nice and compact.
How well do they work?
About the same as a shortened dipole of the
same length. If you build a full size version, the
antenna will perform as well as a full half wave
dipole on the lowest band of the end-fed.
Overall performance of the 5 band 24m
long 80, 40, 20, 15 and 10m band end-fed
is about the same as the performance of a
ZS6BKW, but there are no troubles hanging
the ladderline part of the ZS6BKW and, as I
explained before, end-fed antennas are often
quite easy to hang in small gardens or, like my
garden, in a very non-symmetrical fashion.
Do not forget placement of any antenna is
very important. You can very easily destroy the
performance of any antenna by putting it in a
totally wrong place and at the wrong height.
For horizontally polarised antennas for 40
and 80m, I would say keep the entire antenna
at least 5m (15 feet) above ground, also keep
the ends of the antenna at least 5m above
ground. This will reduce ground losses very
much in any wire antenna. For horizontally
polarised antennas on higher bands, try to get
them at least a half wave up from ground – the
higher the better.
Conclusion
I only once bought an HF antenna and was so
disappointed in its performance that I promised
myself to only use homebrew antennas in the
future. I now build all my own antennas for HF,
VHF and UHF. I have built over 200 and have
given away over 100 of them as I could not
possibly keep and use them all myself. Lots of
antenna parts were recycled from one design to
another. It has been fun!
WEBSEARCH
[1]
php?f=5&t=6682&start=45
[2] FIGURE 7: End-fed simulated performance on 10m.
FIGURE 6: End-fed simulated performance on 15m.
FIGURE 5: End-fed simulated performance on 30m.
FIGURE 4: End-fed simulated performance on 40m.