Difference between revisions of "Antennas"

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Revision as of 20:12, 2 February 2019

The type of antenna largely depends on the type of ground station. A no rotator ground station will benefit from a different type of antenna (omnidirectional) than a rotator based ground station (directional). The two different approaches are explored below. In addition to the choice of antenna the choice of location for the ground station will have an effect on the quality of observations.

Non-Rotator Ground Station (Omnidirectional)

This type of ground station will require an antenna that will give a broad coverage from its fixed position. It is therefore not just the antenna that needs to be considered but also the proximity of buildings, geography or metallic structures that might be in the path of a line of sight between the ground station and satellite.

Typical ground stations have had success with simple wire antennas that can be commercially bought or made at home. Colinear or ‘white stick’ antennas are vertically polarised omnidirectional antennas. These have anecdotally been used for successful satellite work but should be avoided. The following are considered suitable choices:

It is highly recommended that you use a mast-mounted Low-Noise Amplifier (LNA) with these antennas.

Commercial Antennas

Homebrew Antennas

WiMo TA-1.gif

WiMo TA-1

VHF Turnstile

Estimated cost: 90€

Some SatNOGS stations using this antenna:

141 - balcony-only-east-passes

33 - G7KSE

129 - Chabot Space And Science Center

VHF Turnstile.jpg

Turnstile

Estimated cost: TBD

Some SatNOGS stations using this antenna:

13 - OZ9AEC-VHF1

7 - Stony

16 - VK5QI-70CM

M2 Eggbeaters.png

M2 Eggbeater

VHF / UHF Eggbeater Antennas

Estimated cost: $304 (VHF), $280 (UHF), $573 (combo)

Some SatNOGS stations using this antenna:

50 - N5CNB-UHF

77 - N5CNB-VHF

VHF EZ-Lindenblad.png

Lindenblad

Estimated cost: TBD

Some SatNOGS stations using this antenna:

12 - W2BFJ

98 - Grove-UHF-01

442 - DL1UNX-FFB VHF

Winkler Turnstile.jpg

Winkler Turnstile

VHF/UHF Turnstile Antennas

Estimated cost: 40€ (VHF), 30€ (UHF)

Some SatNOGS stations using this antenna:

TBD

UHF Paralindy.jpg

UHF Parasitic Lindenblad

Estimated cost: $15 (with access to a 3D printer)

Some SatNOGS stations using this antenna:

300 - KB9JHU-Experimental

32 - SV1QZZ - UHF #2

187 - K3LRD UHF Lindenblad

Quadrifilar Antennas.png

Quadrifilar Helix Antenna (QFH)

Estimated cost: TBD

Some SatNOGS stations using this antenna:

272 - K3LRD VHF QFH

255 - EA5BZ - Elche

183 - SPUTNIX-R2ANF-VHF/UHF-stationary

Vhf moxon turnstile.png

"Turnstiled" Moxon

Estimated cost: TBD

Some SatNOGS stations using this antenna:

TBD

Rotator Ground Station

A rotator based ground station is able to make use of directional antennas. These will have a directional gain, meaning that you will need to point them in the direction of the satellite but the signal you receive will be stronger and for longer. They will allow much lower to the horizon passes to be received and more successful observations. These are not complex antennas but the choice will depend on the type of satellite and there are variations on the main types: yagi, helical and quad.

Commercial Antennas

Homebrew Antennas

M2 Leopack.png

M2 Circularly Polarized Yagis

VHF/UHF Cross-element Yagi

Estimated cost: $296 (UHF), $296 (VHF), $638 (Combo kit)

Some SatNOGS stations using this antenna:

2 - KB9JHU

109 - EA6WQ - Tomas Orzaez

25 - N7IPY

Cross element UHF yagi.jpg

Yagi Antennas, Cross-element yagi antennas

VHF/UHF directional antenna

Estimated cost: TBD

A common type of antenna that is either horizontally or vertically polarised. Simple to construct and suitable for a large number of satellites.

Some SatNOGS stations using this antenna:

TBD

Wimo xquad vhf.jpg

WiMo X Quad

VHF/UHF Cross-element Quad

Estimated cost: 149€ (VHF), 149€ (UHF)

Some SatNOGS stations using this antenna:

6 - Apomahon

49 - OZ7SAT

232 - VK5QI-AZ/EL

Satnogs helical v1.jpg

Helical Antennas

UHF circularly polarized directional antenna

Estimated cost: TBD

A less common type that are circularly polarized. The antenna looks a bit like a corkscrew and can be either LHCP (Left hand circular polarisation) or RHCP (right hand circular polarisation).

Some SatNOGS stations using this antenna:

6 - Apomahon

Arrow Portable Yagi.jpg

Arrow Dual-band portable yagi

VHF/UHF portable yagi

Estimated cost: $83-$149

Some SatNOGS stations using this antenna:

TBD

Elk Log Periodic.jpg

Elk Log Periodic

VHF/UHF portable yagi

Estimated cost: $130-$163

Some SatNOGS stations using this antenna:

TBD

A radome design is available from SatNOGS. This will protect the ground station from the elements in all but extra ordinary conditions. The design can be found here and construction guide here