Free dictation software on different platforms
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What does 0.73 dB above background equate to in dBi for hydrogen line horn? I have a typical SETI of Plenty, 4 feet long and 3 feet wide, at 1420 MHz. Read the caveat that comes with this post.
Hydrogen-Line Detection vs Antenna Gain A measurement of 0.73 dB above background does not directly convert to dBi because they describe different things: So, whilst an attempt is made below…
Calculating gain achieved with LRO SETI Horn of Plenty using RTL-SDR V4 software-defined receiver 29/5/2026
Jason has calculated gain based on my plot below: I’m getting about 0.73 dB above background for that trace so pretty consistent with your previous results. Looks good! Jason Burnfield
Table comparing dB and dbi gain of SETI Horn of Plenty compared to 1m dish, 1.5m dish, 2m dish, 3m dish, 17 element patch Yagi, 86cm Ptarmigan Triffid 4 x 4 dipole array.
At the 1420.405 MHz hydrogen line, the SETI Horn of Plenty is generally quoted at about +20 dBi gain (roughly +18 dBd). For comparison: Antenna Approx Gain (dBi) Approx Gain…
Would the Active Antenna Amplifier (model AAA-1C) make a good masthead amplifier for a VLF loop antenna (SIDs)?
https://active-antenna.eu/amplifier-kit Yes — the is actually a very good choice for VLF loop work and SID detection, much better suited than the LA-200 type devices. The important point is that…
Is a LA-200 active audio loop amplifier a good choice for amplifying VLF loop antennas for SID detection?
If by “LA-200” you mean the common audio induction-loop amplifier units (such as the Sarabec LA-200), then no — it is generally not a good choice as a front-end amplifier…
It is commonly stated that acceptable error in flare angle on a SETI Horn of Plenty is lambda/4. Why is this amount chosen?
The commonly quoted lambda/4 criterion is not really a limit on the flare angle itself; it is a limit on the resulting path-length or surface-position error caused by a construction…
How to disable automatic updates on my Linux Ubuntu computers operating radio telescopes, so that the systems are stable.
Yes. On Ubuntu you can disable automatic updates completely, or just stop the update notifications while still updating manually when you choose. Temporary: stop automatic updates Open a terminal and…
Calculate for me, with downloadable sheet with equations as well, the practical maximum acceptable deviation in flare angle (give the actual angles too) of SETI Horn of Plenty with usual dimensions (give those) and with extension 1m in length on end.
https://www.astronomy.me.uk/wp-content/uploads/2026/05/SETI_Horn_Flare_Angle_Calculations-1.docx Using the usual amateur SETI “Horn of Plenty” dimensions: the flare half-angle is: alpha = arctan((A – a)/(2L)) Substituting: alpha = arctan((0.91 – 0.165)/(2 x 1.22)) alpha = arctan(0.3053)…