What are best specifications for cavity filters for 1420 MHz Hydrogen Line work?
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For 1420 MHz (the H I line at 1420.4058 MHz), the “best” cavity filter depends on where you place it in the chain (pre-LNA vs post-LNA) and what you need…
2025
How to control 12 V and 26 V coaxial relays through USB.
Good — that’s a nice setup for remotely switching antennas, receivers, or feed chains. Let’s outline how to get both coaxial relays (12 V and 26 V types) under PC…
Ultra-wideband (UWB) cavity filters
Ultra-wideband (UWB) cavity filters are specialized RF/microwave filters that maintain the low loss, high power handling, and excellent selectivity of traditional cavity filters, but over a much wider fractional bandwidth…
What is best type of power supply to use for bias-tees that power LNAs at dish feed in hydrogen line systems?
Short answer: use the quietest DC you can. In practice that means: Why (and how) Hydrogen-line work is extremely sensitive to conducted and radiated hash. Switching PSUs produce combs that…
What is a practical way of generating low resolution images of Milky Way using interferometry with 2 x 150cm dishes at 1420MHz?
What is a practical way of generating low resolution images of Milky Way using interferometry with 2 x 150cm dishes at 1420MHz? Following suggested process and Python script comes from…
Pros and cons of SAW filters vs Cavity filters
Here’s a concise, technically balanced comparison of SAW (Surface Acoustic Wave) filters and Cavity (Resonator) filters — especially relevant to radio astronomy, RF front-ends, and communications receiver design. 🧩 1.…
Compare the performance of 80cm, 90cm, 100cm, 110cm, 110cm, 140cm, 150cm, 180cm, 240cm, 300cm, 500cm, 1000cm dishes for 1420MHz amateur radioastronomy
The attachments mentioned in the discussion below are available in following downloadable ZIP archive: https://www.astronomy.me.uk/wp-content/uploads/2025/10/Comparing-dish-sizes-performance-H-Line-311025.zip Here’s a practical comparison for your dish sizes at the HI line (1420 MHz), assuming…
Compare the Intel Core i7‑1065G7 microprocessor with the first-generation desktop/server era Intel Core i7‑930 for amateur radio astronomy applications
If you compare the Intel Core i7‑1065G7 with the first-generation desktop/server era Intel Core i7‑930 (or broadly the 1st-gen “Nehalem” i7s) you’ll find major architectural, process, power-efficiency and functional differences. Below is a breakdown…
Mini‑Circuits ANNE‑50L+ 50 ohm 1W SMA coaxial terminator
The Mini‑Circuits ANNE‑50L+ is a very good choice for many purposes—let’s evaluate it specifically for your radio astronomy calibration use case (receive-only, around ~1.42 GHz). Below I’ll walk through its merits,…
Not all 50 Ω dummy loads are the same when used for calibration in radio astronomy
Excellent and subtle question — and one that’s very relevant for radio astronomy calibration.Short answer: not all 50 Ω dummy loads are the same, even though they nominally measure “50…