40m 3 Element Vertical Array

Description

40m hardware kit for either:

• Three-in-a-row Vertical Array
• Triangular array.

(Note alloy cap change from 2023 Spec model)

This is complete kit ready to go. What’s in the bag:

• 3 x DX Commander 10m poles
• 3 x Regular DX Commander Ground Plates
• 3 x SO239 for all element
• 3 x Retail guy points
• 100m DX10 antenna wire (good for 1500W SSB) antenna wire
• 100m Radial Wire
• Set of nuts, bolts and washers for all elements (circa 22 each with spares)
• Circa 22 fork connectors
• Circa 4 x heat shrink lengths
• 3 x 10m Paracord lengths for guying (just supply your own guy stakes)
• HCL Stay Up kit for each pole

The construction method is very easy and each element is based on a spacing of 8m between each vertical element.

For three-in-a-row users, the following dimensions produce a perfect match at 7.1Mhz.

INSTRUCTIONS:

• Fit the Ground Plate by unscrewing the cap at base of pole and gently screwing it back on again after nesting the Ground Plate over the threads.
• Fit SO239s and solder your elements (see below)
• Fit the bolts, washers and wing nuts to each of the Ground Plates
• Extend the telescopic pole
• Fit the guy point by slipping it all the way down the pole (It will sit on top of the tape and cable tie at the first join – see below)
• Fit HCL Clamps (as per the kit user guides)  (Optionally for OCD builder, use 2 x wraps of quality insulation tape on each of the joins – perhaps a wrap of self amalgamated tape)

Use spacing of 8.75m between all elements – and erect ONE element as a time.

Initially build all elements (use the SO239s supplied) and use an SWR meter to check for resonance as follows:

• Driven element tuned for 7.255 Mhz (use SWR meter)
• The front (director) element tuned for 7.395 Mhz
• The rear tuned for 7.035 Mhz

(You can proportionally move these frequencies up and down to achieve your desired part of the band but it will have a wide bandwidth).

Suggest cutting your element about 11.2m long, gently helically wind it around the pole (not more than 1 wrap per metre) and fold it back on itself so it comes back down the pole about 1.5 to 2m.

• TUNING: Initially, build a single vertical and get it tuned for 7.255 MHz on your analyser / SWR meter then lay it on the ground and do the same for the rear (reflector) and tune that for 7.395 MHz. Lay that down and again do the front (director) and tune that for 7.035.

Do the same with Reflector and Director then:

• Take 2 x PL259 connectors and SHORT them out with a small piece of wire between the centre conductor and the body. Screw together and cover in self-amalgamating tape.

Once complete, you should achieve an impedance of around 40-50 ohms. I achieved a perfect match at 7.175 Mhz (may be moved up by shortening 10cm).

Warning: Impedance can change depending on surroundings / ground. Consult your favorite antenna book (ON4UN’s Low Band DX Book is good).