Erste Erfahrungen mit einem zusammenfaltbaren …...March 24th, 2014 Slide 11 OV Ludwigsburg P06...

Slide 1March 24th, 2014 OV Ludwigsburg P06 Oliver Durm, DL3SDW / N7SDW

Assembly & Setup Folding Antenna

Eine kompakte 6-Band Richtantenne für KW

Erste Erfahrungen mit einem zusammenfaltbaren Hexbeam

von Oliver Durm (DL3SDW / N7SDW)



Contents

• The following slides are an extraction out of the presentation „1st Experiences with a foldable Hexbeam“ which was presented at the monthly meeting of the HAM club of OV- Ludwigsburg (DOK P06) on March 24th, 2014



Assembly of the folding Hexbeam

Hints and Experiences



Inserting the carriage bolts into the hub

A piece of wood for supporting the assembly




Another piece of wood with a 7mm hole for supporting the assembly




Pressing the square sectionOf the bolts intoHub halves



DL3SDW's approach of mechanical tuning...

for a symmetrical shape



DL3SDW's approach for mechanical tuning...

• The basic shape is a hexagon with 6 equilateral triangles

• Keeping b = constant at all triangles

• No bending of the spreaders possible• Will (must) result in a symmetric look of the hexagon

α = 60° → a = b = c

Shape of the Hexagonal Beam

α α

α

b

a c



Mechanical tuning – step by step 1/4

• Mount the wire clips on each spreader at the „start location“ which is suggested in the manual

Default distance - out of manual

Distance d

Distance @ DL3SDW

Final positions of wire clips at DL3SDW`s folding antenna after electrical and mechanical tuning:

20m band: 308,0 cm17m band: 237,0 cm15m band: 203,0 cm12m band: 170,0 cm10m band: 150,5 cm




• Connect one dipole leg of the 10m dipole to the feeder

• Attach the wire to the 1st clip and STOP:

• (a) measure the distance d between centre of the wire clip and the outside of the feeder tube (blue arrow)

• (b) the mounting wire length from spreader to spreader (centre of wire clip's) is calculated as follows: elem_length = d+1.5cm

• (c) mark this length and click the element wire into the wire clip that this marking is at the centre of the wire clip

elem_length

Distance d

1.5cm




• (d) Now, measure the element_length to the next wire clip and lay the element into this next wire clip

• (e) by proceeding so, you ensure that all distances between the spreader stay constant and the spreaders won't bend to left or right side.

• (f) take the wire back to the feeder and tighten it with the screw. If it fits well, continue with the next element of the consecutive frequency band

• In case the wire is too short and you can't connect it with the screw to the feeder, move all wire clips 1cm towards the feeder and restart again measuring the distances as in (a), continue then as described in (b) to (f)

• In case the wire is too long, please continue in the following way (g)




• (g) If the wire is too long, bend it as shown on the sketch to determine the length 'half_delta_too_long' of which it is too longdelta_too_long = 2 * half_delta_too_long

• (h) Now you can re-calculate the new wire clip position:move_wire_clip = delta_too_long / 6

• (i) Move the wire clip's by the value you calculated in (h) away from the feeder

• Restart at (a) by continueing so, your folding antenna will always look symmetrical and you achieve the optimum tension of the wire elements between each spreader

Half_delta_too_long



Now, the antenna looks symmetrical



Now, the antenna looks symmetrical



Summary

• The Hexbeam as a folding antenna is

• Lightweight and compact for transportation• Small wind cross section, however:

• let's see how it behaves at extreme weather conditions (e.g. rain with ice, snow)

• Versus time and continous UV light exposure

• Only about 3.20m turning radius• Nearly equivalent to a 3-element beam in terms of Gain and F/B

ratio• No significant sidelopes• Wideband – no antenna tuner required• Without any traps

• thus no Q-decreasing nesting place for little animals like bugs, spiders, ...

• For up to 6 bands (20m .. 6m)

The „Allrounder“ for portable and permanent Installations



Thanks for your attention



Appendix

Source of Information, Links



Appendix & Source of Information

• Www.foldingantennas.com• Www.g3txq-hexbeam.com• Www.karinya.net/g3txq/hexbeam• Www.dl7io.de/reflectedw/• Www.dj4uf.de/antennen/hexbeam.html• Www.Sp7idx-hexbeam.eu• Www.k4io.com/index.html• www.leoshoemaker.com• http://www.midcoast.com/~w1gql/hex/hexbeam.htm• Http://kk7s.net/2012/08/11/the-dl1elu-folding-antenna/

http://Www.foldingantennas.com/

http://Www.g3txq-hexbeam.com/

http://Www.karinya.net/g3txq/hexbeam

http://Www.dl7io.de/reflectedw/

http://Www.dj4uf.de/antennen/hexbeam.html

http://Www.Sp7idx-hexbeam.eu/

http://Www.k4io.com/index.html

http://www.leoshoemaker.com/

http://www.midcoast.com/~w1gql/hex/hexbeam.htm

http://kk7s.net/2012/08/11/the-dl1elu-folding-antenna/

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Erste Erfahrungen mit einem zusammenfaltbaren …...March 24th, 2014 Slide 11 OV Ludwigsburg P06...

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