xianmingfeng/foldable-u9-yagi

A portable antenna design featuring uni-body, small storage form-factor and short deployment time for satellite QRV outdoor

Fold-able 9-El. 430M Yagi Antenna

This is a portable antenna design featuring uni-body, small storage form-factor and short deployment time for satellite QRV outdoor. The antenna is designed for no assembly and fully tool-free deploying. The building processes of this antenna are designed for DIY at home.

This project includes a fold-able boom using hinge, a connector for driven element and a set of element supports featuring fast deployment. They are not limited to this particular antenna, but can be applied to any antenna design with the same boom and element diameters.

The elements' dimensions are based on DK7ZB's Yagis ultralight 9-EL. 70cm 50Ω.

Here is a video demo for this antenna.

The objectives for this project are:

• Lower the required time of setting up antennas when QRV satellite outdoor.
• No screw driver is required.
• Less separated parts possible.
• Minimal adjustments required.
• Small form-factor when storage.
• Enough gain for satellite DX.
• Cheap to build.
• Ready for rotator installation.

Many thanks to DK7ZB, BG7XWF, BI7MPS and all the helps and feedback to make this happen.

Without them, this would not be in the current state.

Changes

• v0.1 (2022-11-20)
  • A new jig for element drilling.
  • A new jig for boom drilling.

Table of Content

Why This

Yagi antennas are usually required when challenging DX via satellite.

1. To get higher gain, a longer boom is required, resulting in inconvenient carrying of the antenna.
2. Portable yagis with fixed element supports are hard to store or carry due to the large size.
3. Detachable elements antennas are easy to carry, but the installation time would be long for all the elements need to be reordered.

Why can't we get a long, high gain antenna with a shorter boom when stored. And a non-fixed elements that no need to detach and assembly?

These are what this project trying to solve.

How it works

How to make one

Components

The fold-able boom requires:

• Hinge (the thing to connect 2 pieces of booms)
• Toggle latch (the thing to lock the booms)
• Adjustment end cap (the thing to make the joint solid)

The element support requires:

• Support base (3D printed part, two versions)
• Partial thread bolt (prevent elements from jamming)
• Spring (to push the elements down to the support)
• Teflon tube (reduce friction between elements and bolts)
• Nyloc nut (to lock the bolt)

The driven element connector requires:

• Fiberglass bar (to connect both side of the elements)
• POM tube (to keep away two side of elements)
• Ring terminal (for feeder connection)

The CAD with all the files are located Here.

General Bill of Materials (BOM)

Tools:

• Drill press
• 2.0mm Drill
• 3.0mm Drill
• 4.0mm Drill
• 10.0mm Drill (optional)
• 3D printer
• M2.5 Tap

Boom BOM:

Component	Standard	Qty
Aluminum Square Tube	16×16×0.9	2
Stainless Steel Hinge	16×86 4 holes	1
Toggle Latch	10mm hole pitch	1
FH M3 Bolt	M3×6	8
Hex Nut	M3	8
End Cap	3D printed	2

Support BOM:

Component	Standard	Qty
Support Base	3D printed	1
SH M3 Bolt	M3×20×6 partial thread	1
Teflon Tube	Φ4×3×6	1
Spring	4×0.4×5	1
Nyloc Nut	M3	1

Connector BOM:

Component	Standard	Qty
POM Tube	Φ6×4×10	1
Fiberglass Bar	Φ4×50	1
BH M2.5 Bolt	M2.5×4	2
Ring Terminal	TBD	2
Washer (Optional)	M3	4

How to use it

How to apply this design to your antenna