| Navigation |
|---|
| Home |
| Quick info |
|---|
| Created on : |
| 2002-08-10 |
| Frequency band : |
| 23cm |
A 23 elements 23cm yagi antenna
The story
I have been looking around for antennas for a while for 23cm ATV reception. Everywhere I go, the prices are the same : far too high for me. The more elements you want, the higher the price of the antenna.
But than I saw Paul (PA0SON) walking with a nice and shiny 23 elements Tonna antenna. The design of the antenna is very straight forward. It's a boom made of aluminium with the elements 'floating' above it on plastic isolators.
I decided to try and rebuild the antenna using a PVC-tube to hold the elements. The elements I made of copper wire. In total this antenna cost me about 4 Euro. So for people with only a small hobby-budget this is a perfect project :)
The size of the elements
| Element name | Distance to the end of the boom (in cm) | Length of the element (in cm) |
| Reflector | 1,6 | 11,5 |
| Driving element | 5,1 | * (see text) |
| Director 1 | 7,6 | 9,9 |
| Director 2 | 11,0 | 9,6 |
| Director 3 | 17,5 | 9,5 |
| Director 4 | 24,3 | 9,4 |
| Director 5 | 31,0 | 9,3 |
| Director 6 | 39,1 | 9,2 |
| Director 7 | 48,0 | 9,1 |
| Director 8 | 57,1 | 9,0 |
| Director 9 | 66,1 | 9,0 |
| Director 10 | 75,1 | 9,0 |
| Director 11 | 84,1 | 9,0 |
| Director 12 | 93,1 | 9,0 |
| Director 13 | 102,1 | 9,0 |
| Director 14 | 111,2 | 9,0 |
| Director 15 | 120,2 | 9,0 |
| Director 16 | 129,1 | 9,0 |
| Director 17 | 138,2 | 9,0 |
| Director 18 | 147,2 | 9,0 |
| Director 19 | 156,2 | 9,0 |
| Director 20 | 165,2 | 9,0 |
| Director 21 | 172,6 | 9,0 |
All elements are placed 4,2 cm above the boom except for the driving element. All elements have a 3mm diameter.
The measures of the driving element are shown in the following picture :
I could not see how the driving element of the Tonna antenna is connected to the coax cable, because the element is one big block of plastic. I connected the cable as shown in the following picture. It works very well, but maybe there is a better way of matching the transmitter to the dipole...
Some images of the antenna :
(click to enlarge)
 |
 |
 |
 |
 |
 |
- Created by Daan Vreeken - PA4DAN -
Email me with questions/comments : Daan <Daan @ pa4dan . nl>