Formula for speed of light, and why it is a constant
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What is the formula for the speed of light? Why is it considered a constant if there is a formula? Great question! Let’s unpack it step by step: 1. The…
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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:
Normalising data files from multiple systems in ezRA
Ted Cline – N0RQV:secret ezCon command option …………. -ezConAntXTVTLevelL 1.3 -3.2 (multiply all AntXTVT sample values and add) Use per file (or batch files) to normnalise
How to take the signals from multiple antenna pairs and turn them into an actual sky image using Fourier transforms
Good question — you’re asking about the heart of radio interferometric imaging: how to take the signals from multiple antenna pairs and turn them into an actual sky image using…
Adding 2nd monopole onto cantenna to improve signal reception
Two monopoles at 90 degrees in cantenna One connects to splitter immediately Two connects via coax either 1/4 wavelength or 5/4 wavelength (more practical length = 26.5cm x 66% (velocity…
How do I normalise data from multiple radio telescope systems so I can combine them together?
How do I normalise data from multiple radio telescope systems so I can combine them together? Great question, Andrew. Here’s a practical, radio-astronomy-friendly playbook for putting multiple systems onto the…
Marcus’s reply about Soapysdr and Sdrplay. Seems the gain settings are backwards in software.
https://groups.google.com/g/sara-list/c/o7xGe2hYkHc/m/VnaAH2u9AgAJ
GPIO Labs 1420 MHz amplifier and filter
Provides an alternative to the Nooelec SAWBird H1 low noise amplifier and filter for hydrogen line radio astronomy. Currently the SAWBird is not available. I have not myself used the…
Cheap RF phase shifter boards
Readily available at cheap prices. The following is one example of many available.