Diffraction effects on prime focus radio dishes
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This comes up a lot in both radio astronomy and satellite communication when using prime-focus reflectors. On a prime-focus parabolic dish, diffraction effects mainly arise from: 1. Feed Support Legs…
Radio Astronomy
Open-source software tools and libraries for interferometry / correlator / radio astronomy
There are several open-source software tools and libraries for interferometry / correlator / radio astronomy work. Depending on how much of the pipeline you want (just correlation, calibration + imaging,…
The “loss surface area” from a prime-focus feed
The “loss surface area” from a prime-focus feed is just the blocked (shadowed) aperture from the feed assembly (feed + support struts). You can estimate it with: So: Ablocked≈Afeed+N w D2,Fraction blocked=AblockedAdishA_\text{blocked}…
Typical weight of plywood used to make ribs on homemade radio dish
The weight of a 6 ft × 4 ft sheet of plywood depends on its thickness and the wood species/density. Let’s go step by step: 1. Area of sheet 6…
Typical weight of 5 ft × 5 ft sheet of fine aluminium window screening used to cover homemade radio dish
Weight of a 5 ft × 5 ft sheet of fine aluminium window screening. Let’s work it out step by step: 5 ft×5 ft=25 ft^2. 25 ft^2×0.035 lb/ft^2≈0.875 lb. That’s…
Comparing signal attenuation at 1420 MHz in short 30cm jumper coaxial cables RG174 vs RG316
For a 30 cm jumper at 1420 MHz (H I line), RG174 and RG316 are effectively neck-and-neck—both cost you ~⅓–½ dB pre-LNA. Quick comparison (30 cm @ ~1.5 GHz) That…
Comparing Software Defined Radios for Radio Astronomy
Here’s a compact, practical comparison of the popular low-to-mid cost SDRs you named (RTL-SDR v3/v4, ADALM-PLUTO, Ettus B210, LimeSDR family) plus a few other often-used SDRs (HackRF, Airspy, SDRplay) produced…
Normalising data produced by Easy Radio Astronomy Software Suite (ezRA) from multiple telescope systems to allow them to be combined to generate combined plots and maps.
This is very much a work in progress, so there isn’t a definitive answer from this post……. Andy Hi Ted, I asked ChatGPT to have a go at this and…
Dipole vs radio dish or horn
If your “two cables joined in the middle, held aloft on poles with a single feed down the centre” is a centre-fed wire dipole / inverted-V style tuned to 1420…
British Astronomical Association Hydrogen Line Group (BAA H-Line Group) Meeting 1st September 2025
The video from this meeting is available here: