The Satenna is a cheap, highly focused, high gain, antenna. It is made from:
- a standard Satellite TV dish, and
- an Antcaptenna, with modified mounting
The Satenna is based on this article by Trevor Marshall.
Introduction
The Satenna is a complete unit: 65cm satellite TV dish, plus
SatCap. The combined gain is about 29 dBi.
You can make your own Satenna by simply buying or building a
SatCap, and combining with a locally purchased satellite TV dish. Search your local 'Yellow Pages' for satellite TV installers for good prices on dishes and roof mounts.
Alternatively - you can purchase a complete Satenna from the Freenet-Antennas Online Store.
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Pictures show the Satenna with the feed oriented for a Horizontally
polarized signal.
Click images to enlarge |
This NetStumbler file shows two sections:
- First = Modified Galaxy 24dBi antenna
(with no extra cable)
- Second = Satenna (65 cm dish + SatCap) and
extension Coax with 1.4 dB loss.
The test setup was:
| AP |
30mW radio connected to a 180-degree waveguide
(See BICTON-AP for details) |
| Distance |
870m |
| Test End |
30mW RoamAboutDS PCMCIA card, 200mm pigtail,
plus antenna under test. |
|
Click image to see
full scale
Download
file |
Because of the high gain offered by this dish, you must attenuate the signal to remain within the maximum 4W/36 dBm EIRP permitted in Australia. The table below shows the configurations that meet the requirements.
EIRP (dBm) = TX Power (dBm) + Antenna Gain (dBi) - Cable Loss (dB)
| Transmitter Power |
Antenna Gain
dBi |
Cable Loss
dB |
Total EIRP
dBm |
| mW |
dBm |
| 30 |
15 |
29 |
8 |
36 |
| 60 |
18 |
29 |
11 |
36 |
| 100 |
20 |
29 |
13 |
36 |
Because of the wind loading with a solid dish, you can not mount up a mast. You
must mount with a dish mount, which you can get from your local satellite TV
installer - check your local Yellow Pages.
Satellite dish mounts come in a variety of standard types:
- Gutter Mount: For tiled roofs, with dish located above the gutter
- Pole mount: For Tiled roofs, located higher up the roof
- Tin Roof: For (you guessed it) metal roofs
- Universal Mount: For mounting on the side of a solid
(brick/Concrete) wall, and a variety of internal roof mounts.
The steps to making your own SatCap are:
- Download the Antcap antenna instructions
- Follow the Antcap antenna instructions, except:
- Bend the antcap differently
- Braze a short length of 38mm pipe on the back, insead of attaching the L-bracket
| Click on images to see full size |
| Picture 1 Cut and bend the Antcap to the shape shown here.
The edges are bent up 90 degrees.
The cutout is designed to suit your Satellite dish arm. |  |
| Picture 2 Another view of the Antcap after cutting and folding. |  |
| Picture 3 Place the LNB clamp in position (as shown in Picture 5).
Mark the insides of the LNB clamp. |  |
| Picture 4 Place a short length (approx 25mm) of 38mm Outside Diameter (OD)
pipe over the pen marks. Braze in place. I use 38mm copper water pipe.
Steel pipe of the same diameter would work as well. |  |
| Picture 5 The final appearance of the rear of the SatCap |  |
| Picture 6 Front of the Satcap with the weatherproof enclosure lid in place. |  |
| Picture 7 Final assembly - front. |  |
| Picture 8 Final assembly - rear. |  |
