AMSAT-SA Dual-band 145/435 MHz Yagi
AMSAT SA have made available a new dual-band 145/435 MHz Yagi antenna for amateur satellite operation.
The Yagi has a unique element called an ‘Open Sleeve’ which is a director very close to the driven element. The driven element is sized for 2 metres. When operating on 70 cm the ‘Open Sleeve’ acts as part of the driven element on 70 cm (Third harmonic of 2 m).
The AMSAT SA version is based on a design by Martin Steyer, DK7ZB with modifications by the late Larry Brown, WB5CXC. The first South African version was a collaboration between Guy Eales, ZS6GUY and Gary Immelman, ZS6YI. It was developed for YOTA 2018 where young people successfully used the antenna operating satellites using hand-held transceivers.
The mechanical structure of the AMSAT SA version was redesigned by Gary, ZS6YI. A choke around the boom was added to isolate the antenna from the coax and reduce the effect human contact has on the antenna. A handle was added on the boom end which makes it more comfortable to hold and further isolates the antenna from the handler.
The antenna is plug and play. No tools are needed except for soldering on a connector to suit the application. It comes complete in a carry bag with full instructions. This antenna can be assembled and dissembled in minutes. For more details and how to order, visit http://www.amsatsa.org.za/
SARL and AMSAT SA members get a discount.
Source SARL News
NORsat-2 in space deploying its antenna. (Credit: Space Norway AS)
Radio amateurs Sean Hum VA3SHV and Jeff Nicholls VA3NGJ worked on the design for a deployable VHF crossed Yagi antenna on the recently launched NORsat-2.
The very high frequency (VHF) antenna was designed to unfold from the CubeSat after receiving a command from the Norwegian Space Center to deploy once in orbit. “This antenna is a completely new type of deployable antenna — it unfolds to be more than three times as large as the satellite that took it into orbit,” says Hum. “This is the first time that a deployable antenna of this type has been contemplated and successfully used as a main mission antenna for a CubeSat.”
On July 20, cameras on board the CubeSat confirmed the successful deployment of the antenna.
Read the full story at http://news.engineering.utoronto.ca/u-t-engineering-designed-cubesats-novel-deployable-antenna-launched-orbit/
Chertsey Radio Club is running a virtual build-a-thon to construct a dual-band satellite antenna for 2m/70cm using low-cost parts and it’s open to all.
They will be using WebEx so access to a PC/Tablet, webcam and Internet will be needed to take advantage of the sessions.
They will be starting the virtual buildathon with the small diplexer kit by HA8LFK, kits will no more than £20 depending on shipping and import tax, as always you pay what we pay, no additional costs.
Please email chertseyradioclub <at> hotmail.com to register your interest.
Further information at
N9TAX Slim Jim mounted on top of the 3-meter mast
The AMSAT-SM website has an article on the dual-band omni-directional 145/435 MHz Slim Jim antenna developed by N9TAX.
Lars SM0TGU comments that the antenna works great for satellite passes below 30 degrees elevation, but signals are considerably weaker on high elevation passes.
Read the AMSAT-SM article in Google English at
Further information on the N9TAX dual-band Slim-Jim antenna is at http://n9tax.com/Slim Jim Info.html
The antenna is available via the Two Way Electronix website at