Applying the Nyquist theorem to radio astronomy
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Great question — this is a very common confusion when first applying the Nyquist theorem to radio astronomy. You do not need a 2.8 GHz sample rate to observe the…
Radio observation in hydrogen line (1420MHz)
I have installed usbrelay softwate on Ubuntu for my 4 relay control board (which works on Windows). Running the command usbrelay detects device but can’t open it.
I have installed usbrelay softwate on Ubuntu for my 4 relay control board (which works on Windows). Running the command usbrelay detects device but can’t open it. If usbrelay sees…
Batch file used at LRO to process data Nov 2025
REM Identify data folder structure. REM The folder structure should be LRO folder with sub-folder called data. Save .txt data files in data and any .ezb and .npz data files…
British Astronomical Association Hydrogen Line Sub-group meeting 1/12/2025
https://files.ad.thornett.net/astronet/BAA_H-Line_Meeting_011225.mp4
How does amplification on Nooelec SAWBird H1 vary with voltage on power supply input?
Short answer: the SAWbird H1’s gain is essentially fixed by its RF amplifier bias network and SAW filter — within the manufacturer’s recommended supply window (≈3.3–5.5 V) you should see…
Comparing RTL-SDR v3 and v4 software defined radios
Here’s what’s inside — i.e. the chips used: In short: R820T2 tuner + RTL2832U demodulator/ADC. Since you’re already familiar with SDR and radio-astronomy, here’s a summary of the key components…
What does following product do? RFandEMF TM-195: 3 Axis High Frequency/RF Measurement, EMF Meter covers 50MHz – 3.5GHz
Here’s what does — and when/how you might use it: ✅ What the device does 🔎 Typical Uses / Why People Use It This kind of RF/EMF meter is commonly…
Dave Bracey’s Hydrogen Line 3D modelling of Milky Way arms
From Dave’s brilliant data set suppled 27/11/2025 – (c) Dave Bracey 2025 – all rights reserved. Taken using Dave’s 150cm homemade backyard radio telescope in Bromyard, England, UK, 2025.
How does the radio frequency SAW filter in a Nooelec SAWBird LNA and filter?
In the SAWBird line of LNAs (e.g., for 1420 MHz, GPS, L-band), the SAW filter is the component that provides the ultra-narrow preselection that makes these modules so effective for…
What is spillover vs ground reflection in radio astronomy?
In a radio telescope’s noise budget, spillover and ground reflection are two distinct ways unwanted radiation enters your receiver. They’re related but not the same: Spillover Spillover is receiver noise…