DodecaWhip - V-Dipole HF portable antenna system

WORK IN PROGRESS - near final revisions.

*Please leave feedback on this tutorial and the prints. It will only help to improve the overall model. 

I am a big fan of open-source and improving upon established products and standards. I am also a big fan of, why spend big $$$ when you have the skills to make something yourself! I had found some Chinese V-Dipoles using telescopic whips, and some American companies versions. There were things that I liked and things that I did not like, and in this case I aimed to design a truly all-in-one sort of antenna with the maximum compatibility and versatility needed for just about any situation you could put it in. 

Meet the DodecaWhip system. Since there are some makers and companies using the Hex as their name brand, I have intentionally designed this hub to have 12 sides (6 large and 6 small) in order to distinguish that this is my original design. I did not just flatten the corners, I spent a long time truly modeling this in Shapr3D, printing/prototyping, and making the adjustments.

***Any similarity in looks or function to others work, or commercial products is just a by-product of a simplistic design that just... works.*** 

Notice that I said simplistic? We are talking about 3D printed parts, 6-10" of wire, several ring-terminal connections, screws, heat-sets and your choice of interface hardware (more on that in the BOM list below). This design and build is truly meant to be whatever you make it.

Here is my contribution to this design, and a parts list of what I have used in my most recent prototypes.

PRINT SETTINGS AT BOTTOM!

BILL OF MATERIALS (BOM)

2x Stainless steel whips (5.6m or 17ft)

• - 6x M3x4x5** heat inserts (lid/cover)

• - 6x M3x8 screws (lid/cover)

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Stainless if possible

• 1x M4x16 bolt (counterpoise)

• 1x M4 hex nut (counterpoise)

• 1x M4 wing nut (counterpoise)

• 1x M4 star washer (counterpoise)

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• 3x 3/8-24 OR M10x1.5 stainless bolts (depending on whip thread)

• 3x 3/8-24 OR M10x1.5 coupling nuts ( “3/8x24 heavy duty” works best, use whatever you can find for M10) If you don't get heavy duty coupling nuts, you are more likely to break your antenna base or studs like this...

• 3x M10 - 3/8 crimp insulated ring terminals (wiring hot and shield bolts)

• 3x M4 crimp insulated ring terminal (wiring counterpoise)

• 3x 3/8(M10) stainless washers (internal bolt mount)

• 3x 3/8 (M10) large stainless fender washers (external lug mount)

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BNC bulkhead mount

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SO-239 Panel mount

• 3x M3x10 stainless screws

• 1x M3x12 stainless screw (SO-239 mount)

• 4x M3 nuts (SO-239 mount)

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• 1x M4x16 stainless Tapered Head Machine screw (T-nut base plate secure)

  • You want a screw that will sit flush when fully inserted!!

• 1x M4 nut (Base plate secure - optionally electrical ground)

OPTIONS FOR MOUNTING!!!

Option 1:

• M10x1.5 OR 3/8-24 bolt through bottom (Dodeca_v1.0 file)

  • Mount without an adapter to other existing hardware

Option 2: (Current model)

• T-Nut base plate 3/8-16 thread (thick tripod thread)

  • 3/8-16 is usually found on light mast tripods for photography (like this)

• Tripod thread adapter 1/4-20 to 3/8-16 

• OPTION: 3/8-16 to 3/8-24 (male to male) adapter

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• 16 gauge wire for internals (smaller may not handle above QRP power, 14g recommended for high power)

  • 16AWG has handled 100w SSB/CW in the summer heat for my personal build. 

Wiring

I will give a brief rundown of how I handled the wiring as a baseline, but this is NOT the only way to wire this:

SO-239 center pin: Join top/center lug bolt AND one of the V-Side lugs. I chose to join the V-side just above the SO-239 panel mount. We will call these "HOT" lugs.

• The two HOT lugs AND the BNC center wires should be joined and soldered into the SO-239 center pin.

SO-239 shield (longer M3 mounting screw)

• Join the BNC panel mount connector ground, the counterpoise ground AND the wire from the shield lug into one M4 ring terminal. This ring terminal is better NOT insulated.

OPTIONAL  - additional ground/shield to the T-nut base. If you use this on a ground spike, you may want this electrically connected. I chose NOT to, I have a metal light stand tripod. 

Assembly

Assembling this is pretty straightforward, however there are some quirks I have learned to make life easier...

• Pre-bend the 3/8 wire insulated ring terminals to point into the housing.

  • Help with aiming the wire before crimping and measuring.

• Pre-solder the 3 HOT wires together after measuring to the SO-239 center pin area.

  • Make sure you measure AFTER crimping/soldering the insulated ring terminals to the wire.

  • Temporarily bolt the assembly together for measuring. 

• Solder the SO-239 un-mounted (wires pulled through this mounting hole)

• Use FLEXIBLE wire is possible, traditional PVC coated wire is tough to bend and maneuver. 

• Keep wires as SHORT as possible. 

• Install the counterpoise ring terminal and screw BEFORE installing the T-nut base.

• EPOXY the T-nut base to to the base of the printed hub. 

  • Yes, this has a M4 retaining screw, but I've noticed in the heat of the day, the T-nut will flex a bit. A little epoxy went a very long way in securing this further. 

Print Settings

Material: PETG or ABS (All of mine have been and current is PETG)

• I would NOT trust this in PLA.

• PETG is slightly flexible, which helps with the windy dynamic loads

Walls: 8

• You want this THICK. The extra walls give this a durable shell that does not damage easily, distributes loads from the whips and mounting. 

Infill: 25%

• Resist the urge to go above this, the walls have it handled!

Top/Bottom layers: 5/5

NO SUPPORTS

Brim if you need it