Geodesic Dome Dish Plans
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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.…
Radio observation in hydrogen line (1420MHz)
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…
Radio observation in hydrogen line (1420MHz)
SETI Horn of Plenty (Hydrogen Line Pyramidal Horn Design Antenna)
Waveguides
WR waveguide numbers and the frequency and wavelengths they cover for amateur adio astronomy projects
Here’s a practical WR waveguide reference table showing common WR numbers, their frequency range, and corresponding free-space wavelengths, and including a selection of sizes useful for radio astronomy and microwave…
Radio observation in hydrogen line (1420MHz)
SETI Horn of Plenty (Hydrogen Line Pyramidal Horn Design Antenna)
Round cantenna and square pyramidal horn calculators available online
Links to two useful calculators below (I have nothing to do with these websites): https://3g-aerial.biz/en/online-calculations/antenna-calculations/cantenna-online-calculator https://www.everythingrf.com/rf-calculators/pyramidal-horn-antenna-gain-calculator
Can I use a square coaxial to waveguide adapter to act as waveguide on my 1.5m dish for hydrogen line?
Short answer: Yes — but with caveats. A square/coax-to-waveguide adapter can act as a waveguide feed/aperture for a 1.5 m dish at the hydrogen line, provided its internal dimensions support…