Testing Helical Antenna


#1

Hello, here reporting my new helical antenna, in terms of the measurements I have used this web page: https://www.jcoppens.com/ant/helix/calc.en.php
These are the data that I entered in the calculator of the page:
Design frequency: 1539.87 MHz
Number of turns: 6
Turn spacing 0.19 (wavelengths)
Materials:

  • Bronze square of 140 mm and thickness: 1,5 mm
  • Copper wire: 3.8 mm (Thickness)
  • SMA Female connector adapter
  • 1 Bolt and Thin wood stick to support the spiral and Cable Plastic Zip ties

The signal is more stable, less packages with errors and good values of SNR that although it is not constant at least maintains higher values with a fine pointing, I would like to know your comments and opinions, suggestions …Here are some photos and screenshots.

Thanks


#2

This is really groovy.


#3

Can you send some side shots and bottom shots of how the SMA connector is installed.

Also some side shots of how the spiraling antenna connects to the SMA etc.

Seasalt


#4

Hi Seasalt, to connect the SMA connector to the spiral I drilled a small hole at beginning of the copper wire but before I flattened the surface a little with a hammer blow so that it is easier to drill…and then place the spiral in its position and thus the pin of the sma connector is inside the hole of the copper wire and then only solder in the hole.


#5

Thanks for the photos.
Does it have to be brass for the refelctor base?, Could I use aluminum or mild steel from a old desktop computer case

The helical wire at the bottom is very near the reflector base where it connects to the SMA, does this affect performance?


#6

You are welcome!..Regarding the material of the reflector can be aluminum or other metal, in my next test I will use aluminum … I have read that this type of antennas is ideal to experiment…about the distance between the reflector and the spiral there must be a Distance of 1.8 mm during the first quarter turn as seen in the instructions and results of the page calculator I used.


#7

Thanks for this.

Last one I promise.

Does it matter if the reflector is a square or circle.

Can the reflector be bigger ? Giving more reflection and therefore a stronger signal?

Seasalt


#8

In most cases I have seen reflectors with a circular shape but also there are square shape … you have to do the tests and compare the results … all this is something new for me and I’m learning along the way.


#9

@Seasalt based on your observations on my helical antenna I have isolated the connection of the spiral to the sma connector with which I have managed to decrease packages with error, but I have discovered that when changing the configuration of the network so that instead of creating an access point Connect to a wireless network the errors were reduced to the minimum practically to 0 as you will see in the screenshot