(click on the photographs to see the enlarged pictures)
160m inv-L to the right of the tower (separation to tower about 50 cm), going
up to 12m height and sloping about 29m downwards to the right (quarter wave
on 160m). Notice the KLM-KT34XA is missing half of the reflector element (after
the last autumn storm of 2008)
this picture is taken from the other side: 160m inv-L to the left of the tower,
sloping towards to left
the 160m inv-L is attached with an insulator to a wooden pole, which in its
turn is attached with some wire to the tower almost at 12m height. The wire
to the right of the inv-L, is the 80m shunt-feed wire (attached at about 11m
height and at about 50cm distance from tower; insulators=distance keepers are
(electrical) 5/8" pvc pipes
the 160m inv-L starts at the right hand side of the green cabinet, attached
to a small piece of 5/8" pvc pipe
the 5/8"pvc insulator is attached with a rope to an aluminum pipe. In front
of the aluminum pipe, you can see a copper ground rod. Two copper ground wires
are attached to the ground rod: one goes to the green cabinet, the other is
attached to the tower leg (the tower has on each leg a 6m deep copper ground
rod)
January 2004 I added a matching LC-network to get a 1.1:1 SWR. This is not necessary,
the SWR without the network was about 1.7:1 - notice the relay with a tap on
the coil, this switches from CW to SSB portion of the band. Total coverage (1.5:1
max SWR) is from 1810-1890 kHz
close-up of the LC-network. Total capacitance was 2nF in this picture (2004),
changed to 1.4nF September 2012. The value of the coil is 2uH.
to the left of the green cabinet, you can see chicken wire (3 cm diameter).
Before 2004, this was all I used...a ground rod and three chicken wires. Nowadays
I have 44 radials permanently under ground (in the garden) and in winter time
I add another 40 on the field. Cannot say I 'feel' much difference between before
and after 2004 (chicken wires versus many radials)
3 cm diameter chicken wire, about 50cm wide, length about 15m
here the three chicken wires are connected together. The chicken wires are each
held between two aluminum bars, with stainless steel screws. The aluminum bars
are then connected to each other. The front aluminum bars hold a chicken wire
with 4,5 cm diameter. All the other chicken wires are 3 cm
this is a view from the 160m inv-L from the street side towards the tower
the end of the inv-L is attached through an insulator and a piece of rope, to
a wooden pole. Height only about 1m above ground
another view of the sloping part of the 160m inv-L, with the 40m 1/4 wave vertical
in the background
this was the very beginning of my 160m inv-L, without radials, without matching
LC-network, just a piece of wire (on photo: brown wire - with green insulating
tape - soldered to an SO-239. The 50 ohm RG-213 coax is connected to the SO-239
with a PL259. Of course you could solder the coax direct to the wire) and some
chicken wire and ground rod (a piece of aluminum pipe, no copper rod yet). More
than 200 countries were worked with this simple inv-L on 160m band
in 2004 when we redid the garden, I buried 44 permanent radials in the garden.
On the field (click on picture) an additional 40 radials are laid out during
winter season. The length of the radials in the garden is variable (7 to 30m),
on the field I used to have both 20 and 40m lengths, but I have changed all
40 radials to 20m length.