Heat Index
Admin
The Heat Index is one of the most useful composite weather measures, especially for gauging human comfort and safety in warm conditions. Here’s a concise breakdown: 🔹 What It Is…
November 2025
What is the “best index” on a weather monitor?
There are a few possibilities depending on what you’re interested in:
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…
Comparison of energy consumption of Raspberry PI generations 3, 4 and 5, and typical mini-PC used at LRO
Here’s a comparison of typical power consumption (no peripherals or display) for each device, measured at the wall under different workloads. Device Idle Power Moderate Load (e.g. data logging, web,…
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…
LRO-H2 Radio Telescope (150cm Solar Cooker Dish)
SDRplay RSPduo Software-Defined Radio (SDR)
Waveguides
Data collection video from LRO-H2 (150cm Dish & cantenna waveguide at 1420 MHz) with beta SDRplay RSPduo ezCol 01/11/2025-02/11/2025
Link below downloads video MP4 file:
Talk on Possible Radio Astronomy Projects to be taken forward by Walsall Astronomy Society 13/11/2025
https://www.astronomy.me.uk/wp-content/uploads/2025/11/Proposed-club-RA-projects-Walsall-Astro-Soc-131025-DRAFT-031125@1700.pdf https://www.astronomy.me.uk/wp-content/uploads/2025/11/Proposed-club-RA-projects-Walsall-Astro-Soc-131025-DRAFT-031125@1700.pptx