Building tuneable waveguide probe
Admin
Since you’re building a tuneable waveguide probe (I’m assuming 1420 MHz given your past adventures…), here’s a clean, mechanically stable way to do it without it turning into a wobbly…
Radio observation in hydrogen line (1420MHz)
What brass tube will snugly fit inside or outside 1/8 inch diameter brass tubing, for making a tuneable cantenna monopole probe?
Here are the standard brass tube sizes that will fit snugly either inside or outside 1/8-inch brass tubing: 📏 Basic Dimensions of 1/8″ Brass Tube So you want tubing whose…
How does X-400 coaxial cable compare LMR 400?
Here’s a comparison of Paradar X-400 Ultra‑low‑loss Coaxial Cable (often called X-400) versus standard LMR‑400 Coaxial Cable (Per Metre) (the well-known low-loss 50 Ω coax): 📡 Purpose & Positioning X-400…
Software for Hydrogen-Line Radio Astronomy (H-Line RA, 1420 MHz)
https://www.astronomy.me.uk/wp-content/uploads/2026/02/Software-for-H-Line-RA-180226-DRAFT-090226@2200.pdf https://www.astronomy.me.uk/wp-content/uploads/2026/02/Software-for-H-Line-RA-180226-DRAFT-090226@2200.pptx
Radio observation in hydrogen line (1420MHz)
SETI Horn of Plenty (Hydrogen Line Pyramidal Horn Design Antenna)
Calculating pyramidal horn gain for range of different apertures
https://www.astronomy.me.uk/wp-content/uploads/2026/02/Calculating-pyramidal-horn-gain-different-apertures-080226.pdf
Signal attenuation (loss) for common coaxial cables at around 1.42 GHz (1420 MHz), relevant for builders of amateur Hydrogen Line radio telescopes.
Loss is a length multiplier, so a 200 ft length would have twice the loss shown above and a 50 ft length would have half the loss. This multiplier factor…
Parts and alternatives that might help you mount a ~30 cm or ~40 cm aluminium ring for a waveguide on AliExpress.
Some parts and alternatives that might help mount a ~30 cm or ~40 cm aluminium ring for waveguides — including raw material you can machine or tube rings / mounting…
How can a 50 ohm resistor be used to produce reference signal on a radio telescope with 50 ohm impedance?
Great question — this is one of those radio-astronomy tricks that feels almost too simple until you see why it works. The key idea A 50 Ω resistor at a…
How to service the 13-element Alex Pettit Hydrogen Line Yagi Antenna
This antenna is used on LRO-H3 at LRO. From Alex Pettit: The spacers and plates are aluminum. The threaded rod they sit on is steel. Measure the DC resistance from…