Chokes for hydrogen line cantenna feeds
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A choke can be added to a cantenna feed to improve performance by suppressing unwanted common-mode currents on the outside of the coaxial cable shield. This results in a cleaner…
Radio observation in hydrogen line (1420MHz)
SETI Horn of Plenty (Hydrogen Line Pyramidal Horn Design Antenna)
Pyramidal Horn Calculator with examples for 1420 MHz hydrogen-line pyramidal horn build.
This calculator calculates the optimal dimensions of a Pyramidal Horn. Click on link below to see examples of calculation for hydrogen line radio observing (1420 MHz): https://www.astronomy.me.uk/wp-content/uploads/2025/12/Pyramidal-Horn-Calculator-with-examples-091225.pdf
Radio observation in hydrogen line (1420MHz)
SETI Horn of Plenty (Hydrogen Line Pyramidal Horn Design Antenna)
Designing and building a 1-metre-aperture horn antenna for 1420.405 MHz suitable for hydrogen-line work.
Below is a complete, practical guide to designing and building a 1-metre-aperture horn antenna for 1420.405 MHz suitable for hydrogen-line work. I’ll give you dimensions, materials, flare angles, feed options,…
In normal retail use paint tins are not made of stainless steel (relevant when used for making cantennas for radio astronomy)
In normal retail use paint tins are not made of stainless steel. Here’s the breakdown: ✔ What paint tins are made of Most commercial paint cans are made from tin-plated…
Geodesic Dome Dish Plans
Creating a geodesic dish can be an exciting project. These structures are efficient, robust, and aesthetically pleasing. Here’s a detailed guide to help you plan and construct a geodesic dish.…
I find that a 2.5 litre paint tin provides the 150mm diameter that seems to suit hydrogen line cantenna. Can I put it inside 5 litre paint tin so that 5 litre tin acts as choke on cantenna? I use the cantenna as waveguide.
Short answer: maybe — but probably not the way you hope. Putting a smaller 2.5 L can inside a larger 5 L can will change the electromagnetic environment of the…
How to make quarter-wave choke for a hydrogen-line cantenna
Below is the simplest and most reliable way to add an effective quarter-wave choke to a hydrogen-line cantenna. This is a standard method used on feedhorns to reduce spillover and…
Ideal diameter and length (or height) of cantenna for hydrogen line radio astronomy
For a hydrogen-line (1420.405 MHz) cantenna, the “ideal length” depends on which style of design you’re aiming for. A cantenna is really a short section of cylindrical waveguide, so its…
Diameter and height of 2.5 litre paint tins in UK
Good question. In the UK, tins of paint come in a standard set of metric sizes. Here’s roughly how diameter corresponds to size — and what you’d see that’s close…
What is widest diameter that works effectively for making hydrogen line cantennas?
Widest usable diameter for a hydrogen-line cantenna For a round “cantenna” (a short section of circular waveguide) working at the hydrogen line (1420.4 MHz), the widest internal diameter that still…