Ideal focus position for Discovery Dish feed (hydrogen line)
Admin
From Alex Pettit 23/12/2025, published on SARA Mailing List, sara-list@googlegroups.com Performance Exceeds anything I’ve seen in the ‘out of the box’ beginner systems ..
Admin
Effect of small hardware changes on 1m class hydrogen line radio dishes on removing radio frequency interference (RFI).
The following information is from Alex Pettit 23/12/2025: For Example, in this case where local RFI is seen from an adjacent monitor to the receiver. The following 3 plots show:…
How much voltage would I loose on 5v linear power supply 5m cable to my LNA?
To work this out properly we need one key missing detail: the cable conductor size (wire gauge or cross-section) and ideally the current drawn by the LNA. That said, I…
How linear power supplies work
Andrew, yes it appears to be pretty much the type of power supply that I was referring to. Although I generally dislike Amazon listings as far as technical information details,…
Is there a better RF switch than HMC849?
Whether a “better” switch than the HMC849 exists depends entirely on the specific application requirements, as different switches are optimized for different parameters. The HMC849 is a specific high-performance, non-reflective…
HMC8038 RF Switch Data Sheet and specifications
https://www.astronomy.me.uk/wp-content/uploads/2025/12/HMC8038-RF-Switch-Data-Sheet.pdf https://www.astronomy.me.uk/wp-content/uploads/2025/12/HMC8038-RF-Switch-Specifications.pdf
Calculating wavelength inside a cantenna at 1420 MHz (Hydrogen Line)
Use <ctrl> <+> on your keyboard to enlarge the image (full image over 1000 pixels wide)
SARA Website Page on Analysis of Data at 20m Skynet dish at Greenbank
SARA’s web Analytical Section … https://www.radio-astronomy.org/node/200 talks of the 20m dish telescope.
Cygnus A hydrogen source type from SARA Meeting 21/12/2025
@Rick K0GD Cyg A is a continuum source, so you won’t see it in hydrogen line. Instead you will just see an increase in power over the whole spectrum when…
Linear vs switched mode power supplies
Here’s a clear, practical comparison, with an emphasis on noise-sensitive and technical uses. Linear Power Supply (LPS) How it works Mains → transformer → rectifier → smoothing capacitors → linear…