British Astronomical Association Radio Astronomy Group H-Line Sub-Group Meeting Recordings
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There is now a new playlist, to make it easier to access these recordings: https://www.youtube.com/playlist?list=PLzBTybazXT4123hs3KiBO28PeMTzc6Cks
Radio observation in hydrogen line (1420MHz)
Solid state coaxial relay
Or….Options in the “RF switching without the clacky bits”! A solid-state coaxial relay is basically an RF switch that uses PIN diodes or GaAs FETs instead of a mechanical armature.…
Best coaxial switching device for my 1420 MHz for reference samples. Does not need to be fast.
ChatGPT: For 1420 MHz reference switching where speed doesn’t matter, go with a latching electromechanical DPDT transfer (coaxial) switch. It gives you the cleanest path, excellent isolation, and rock-solid matching.…
Was Tohtsu CX-520D a good choice?
Question: I am concerned that I have made a bad choice by buying Tohtsu CX-520D coaxial relay from ebay to use to switch reference signal in amd out of my…
Tohtsu CX-520D Coaxial Relay
Tohtsu CX-520D coaxial relay purchased from ebay Nov 2025: Specifications: Three x type N female connector, has a common and a NC contact. Max input power: 300W pp at 1000…
Better to use a portion of signal spectrum as reference signal, rather than image shift.
From Alex Pettit, via SARA Mailing List, 5/11/2025: Andrew, see if this analogy helps : The Top 3 Data/Drift Pair shows using an image shift to measure system or sky…
What if any is potential benefit for adding filtering and amplification at antenna in meteor scatter detection arrangement at 143.050 MHz?
What if any is potential benefit for adding filtering and amplification at antenna in meteor scatter detection arrangement at 143.050 MHz? Short answer: yes—put a low-noise preamp at the antenna…
Potential Small Radio Telescope Drift Sources
Following from Alex Pettit by email 4/11/2025:
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…
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,…