13cm S-Band Helical Antenna

13cm S-Band Helical antenna

Since the antenna has to go on the satellite mast, and there is not much room for a dish, I decided to start off with a Helical antenna.

I have build several in the past, and took the design from VE2ZAZ

Back in 2005-2007 I had good experience with this helical design, so I did not hessitate and started to build one again.
Only with some more Turns, to be precise 34 turns.. (That is what you max get from a roll of 5m 6mm2 wire from the store 🙂
Theoretical gain of 19dBI

After building this helical, I have set it up for testing, and the SWR was good enough 1/1.3 on 2400MHz 🙂 so no tuning needed further here..

I have made a drawing of my antenna, please refer to VE2ZAZ’s design for specific dimensions..

Click Image for full view

13cm-helix-support-dimensions

Some detailed pics of building the Antenna..

First I started to make the Reflector plate with the N Connector

13cmhelical3

A Detailed shot of the dielectricum of the N-Connector, That is cutoff at approx 1,2mm above the Reflector surface.
As you can read on the website of VE2ZAZ the coupling Tab needs to start off at this point..

13cmhelical4

All mounting is done with Stainless steel hardware! Never using anything other!

13cmhelical5

Drilling/Milling the standoff mounting points.. note that the standoffs start off from the inside.

13cmhelical1Detailed picture of the standoff mounting hole.

13cmhelical2

These cabinet handles are perfect material for making standoffs!, they are 10mm in diameter.
Tip for dutch hams, buy them at Praxis, they have 4 in the bag for a good price 😉
13cmhelical7

Detailed shot of the finalzed standoff, note the hole!, the wire is 2.9mm the hole is drilled at 3.5mm..
This because the wire is bend in a radius, so drilling it with 3mm will not fit!13cmhelical8The helical is wound on a 40mm PVC pipe.. when done and stretched out to the correct spacings, the diameter will just perfectly shrink down to the desired diameter 😉13cmhelical6

Detailed shot of the helical wound thru a standoff

13cmhelical14

Detailed shot of the finalzed standoff, note the hole!, the wire is 2.9mm the hole is drilled at 3.5mm..
This because the wire is bend in a radius, so drilling it with 3mm will not fit!13cmhelical8The helical is wound on a 40mm PVC pipe.. when done and stretched out to the correct spacings, the diameter will just perfectly shrink down to the desired diameter 😉13cmhelical6

Detailed shot of the helical wound thru a standoff

13cmhelical12

Detailed shot of the helical and coupling tab that is going to be soldered to the N-Connector

13cmhelical10Detailed shot of the helical and coupling tab that is going to be soldered to the N-Connector13cmhelical11

Voila a 13cm Helical for S-Band use 🙂

Tip!, Spray paint the antenna with an Acryllic blank paint, this for protecting the copper helical.13cmhelical9