How to calculate F/D ratio of radio dish?
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F/D is purely geometric. Once you know any two of diameter, focal length, or depth, you can calculate it. Definitions: D = dish diameterf = focal length (vertex to focus)d…
Radio observation in hydrogen line (1420MHz)
How do the dimensions of the hydrogen line horn made by SETI League & listed on astronomy.me.uk compare to the ones in https://lweb.cfa.harvard.edu/~npatel/hornAntennaAASposterPDF2.pdf and https://www.ece.mcmaster.ca/faculty/nikolova/antenna_dload/
Here’s a side-by-side comparison of horn-antenna dimensions for hydrogen-line (≈1420 MHz, λ ≈ 21 cm) observation from SETI League / astronomy.me.uk recommendations and the academic designs referenced in the Harvard/McMaster…
What is maximum flare angles of hydrogen line horn antennas before the antenna develops problems?
Short answer first, then the nuance. TL;DR (rule-of-thumb) For 1420 MHz hydrogen-line pyramidal horns: That’s why almost all serious 21 cm horns cluster around 15–25°. What “problems” actually appear —…
Scaling the SETI Horn of Plenty (Hydrogen Line Horn Antenna)
Hi Andy, You recently asked a question on the SARA forum “I notice that the SETI Horn of Plenty is a smaller version of the original Ewen Horn that first…
If I want to make a bigger version of the SETI Horn of Plenty, still for 1420 MHz, how do I increase the dimensions?
Same frequency, physically bigger horn — not frequency scaling.This is where horns stop being “just scaled” and start being designed. Short answer first:You increase the aperture size, but you do…
How does flared section of hydrogen line horn antenna scale with changes in wavelength measured?
Short answer: it scales linearly with wavelength.Longer answer (the bit you actually care about 🙂): For a hydrogen-line horn (≈1420 MHz, λ ≈ 21 cm), the flare geometry is set…
Find me an URL for original SETI Horn of Plenty dimensions
Following is result of asking ChatGPT the above question 27/1/2026!!!! Here’s a source that actually describes the original SETI Horn of Plenty antenna design and its dimensions: 🔗 SETI League…
Data .txt Files & Timelapse Video of Data Collection of comparison between ezCol.py & ezColGR (GNU Radio version) on LRO-H2(SCRT) using same 150cm dish, feed and SDR 24-25/1/2026
These are both relatively long integration times on the Intel i5 MiniPC used for this experiment. The numbers are not equivalent – in both cases I attempted to obtain an…
Data Collection Videos from LRO-H1(Ptarmigan Array) 23-24/1/2026 with use of ezColGR test GNU Radio Script
Screenshot: Data Collection Videos: Data Files: https://www.astronomy.me.uk/wp-content/uploads/2026/01/LRO-H2_ezColGR260104GR_260123_13.txt https://www.astronomy.me.uk/wp-content/uploads/2026/01/LRO-H2_ezColGR260104GR_260123_14.txt https://www.astronomy.me.uk/wp-content/uploads/2026/01/LRO-H2_ezColGR260104GR_260124_00.txt