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| The SRC X65 with its original box, now long gone. |
I've been using a
65ft inverted L with a 9:1 unun for some time. It was originally made
by the Snowdonia Radio Company (SRC), but I have had to rebox it as
the unun box cracked and filled with water.
With a new box and stainless steel bolts and fittings, the antenna works well from
20m – 10m, with coverage of 40m and 80m as well, although
performance isn't fantastic on these lower bands.
The antenna is a
vertical for the first 8m, supported on a fibreglass fishing pole. It
then goes off at quite an acute angle down to the garden fence. The
pole is held against a tree trunk with a couple of bungee cords and
has a single earth stake. It is fed with RG213 coax with a 10-turn
choke at the feedpoint.
What I did notice
was that the antenna didn't work very well on medium wave, long wave
or with LF aeronautical NDBs, so I thought about trying something.
The unun box now has
a DPDT switch attached that switches out the unun and feeds the
antenna directly. This has made a big difference to medium wave with
signals romping in. The switch is waterproofed so all I have to do is
go outside, flick it if I want to use the antenna on medium or long
wave, and flick it back to engage the unun, which gives a better
match on the upper HF amateur bands.
Without the unun I
also get a better match on 80m, which is a bonus. Simon and SRC are
no longer trading unfortunately, but you can build your own 9:1 unun
quite easily.
While it is no Flag,
Kaz or Wellbrook Loop, it does make a simple omnidirectional antenna
for SWLs and hams.
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