Potential Small Radio Telescope Drift Sources
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Following from Alex Pettit by email 4/11/2025:
Radio observation in hydrogen line (1420MHz)
Best method to obtain reference samples for Hydrogen Line work
On 2025-11-04 03:27, ‘Andrew Thornett’ via Society of Amateur Radio Astronomers wrote following in bold, then Marcus Leech responded with answers in italics. Hi All, Interesting discussion on the resistor…
Three versions of Nooelec SAWBird H1 LNA
I made following comment on SARA mailing list 3/11/2025. “I was talking about the Nooelec SAWBird H1 LNA, which it turns out has 3 versions. Worth saying that it is…
Real life test results comparing amplifier performance at 1420 MHz
These results were presented by Andrew Sutkowski at the BAA Hydrogen Line Sub-Group Meeting 3/11/2025. His preference is the WVURAIL ones, which are designed as part of the DSPIRA project,…
In the design of a cantenna for 1420 MHz radio astronomy, how far from bottom of can should be monopole be located?
In a cantenna for 1420 MHz, how far from bottom of can should be the monopole? Short answer: place the monopole about a quarter of the waveguide wavelength (λg/4) up…
Does it matter what the monopole aerials inside a waveguide such as a cantenna waveguide are made of?
Andrew Sutkowski checked his feed and found monopole probe made of 1/8 inch copper tube far better at picking up 1420 MHz hydrogen signal than bare copper wire (information from…
What is a Kumar choke for radio frequencies?
A Kumar choke (often called the VE4MA or Kumar feed/choke) is a choke-ring / cavity around a horn/feed that suppresses unwanted surface and coaxial currents and “traps” or reflects energy…
LRO-H2 Radio Telescope (150cm Solar Cooker Dish)
Radio observation in hydrogen line (1420MHz)
Waveguides
In LRO-H2, I use a cantenna as my waveguide, and aim this at the dish, rather than out into space. Does the presence of the dish change the ideal dimensions for the cantenna and position and length of the monopole inside it?
Short answer: No—the dish doesn’t change the waveguide dimensions of the cantenna.The can’s internal diameter and the probe/back-short geometry are set by your operating frequency and waveguide mode, not by…
Results drift scan LRO-H2 two orthogonal monopoles for SARA RTOP 2/11/2025
https://www.astronomy.me.uk/wp-content/uploads/2025/11/Results-drift-scan-LRO-H2-two-orthogonal-monopoles-for-SARA-RTOP-021125.pptx
LRO-H2 Radio Telescope (150cm Solar Cooker Dish)
Radio observation in hydrogen line (1420MHz)
SDRplay RSPduo Software-Defined Radio (SDR)
Processing first light data from LRO-H2 using beta ezCol SDRplay Python script 2/11/2025
https://www.astronomy.me.uk/wp-content/uploads/2025/11/Beta-ezCol-SDRplay-Data-Analysis-First-Light-for-SARA-RTOP-021125.pptx https://www.astronomy.me.uk/wp-content/uploads/2025/11/LRO-H2_RSPduo_251102_00.zip https://www.astronomy.me.uk/wp-content/uploads/2025/11/Ted-Clines-new-ezCol-and-SDRplay-drivers-251101a.zip