John Berman’s SID Presentation from BAA VLF Meeting 16/3/2026
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Click on link below to download: https://www.astronomy.me.uk/wp-content/uploads/2026/03/John-Berman-SID-Presentation-BAA-VLF-Meeting-160326.pdf
Radio Astronomy
Sketch a practical 20 kHz tuning arrangement (variometer vs switched L/C vs active front-end) tailored to radio astronomy
At 20 kHz you’re really designing a resonant system, not just adding a tuner box. For your kind of radio astronomy / interferometry work, the most practical approach is a…
Does anyone sell off the shelf antenna tuners that cover 20khz for VLF SID Monitoring?
Short answer: yes—but not in the way you’re probably expecting. 🚫 Off-the-shelf ham tuners: no All the usual amateur ATUs—like only cover roughly 1.8–30 MHz (HF). Even the “wideband” ones…
When making a VLF loop antenna to monitor SIDs, do you get better signal using less copper wire but on a bigger frame?
For a VLF loop antenna used to monitor Sudden Ionospheric Disturbances (SIDs), the received signal strength mainly depends on the loop area × number of turns, not simply the total…
Very Low Frequency (VLF) Aerials at Lichfield Radio Observatory (LRO)
70cm aerial for UKRAA 23 kHz receiver: The 134cm LRO Aerial:
Latest Spectrum Lab USR settings file that works successfully with LRO 134cm VLF aerial with direct input into USB soundcard and Spectrum Lab Software as of 16/3/2026
Click on link below to download – provided as ZIP file – unzip this into your Spectrum Lab configurations folder: https://www.astronomy.me.uk/wp-content/uploads/2026/03/LRO_VLF_Config_works-with-134cm-aerial-LRO-PC-10-210226@1800.zip
Alex Pettit’s new RFI removal regime in H-Line 3D
New process to clean up hydrogen line data, removing RFI. https://github.com/AP-HLine-3D/HLine3D/blob/main/JAVA_HL3D_mX%2Bb_RFI_V2.2_08Mar26_IFAvg2csv.jar start with zero frequency width and gradually widen.
Tell me what a SID (Sudden Ionospheric Disturbance) is and what range of frequencies are covered when monitoring for SIDs.
A SID stands for Sudden Ionospheric Disturbance. It refers to a rapid change in the ionosphere caused by intense solar radiation, usually from a solar flare. These disturbances are commonly…
Are there disadvantages of using SAWBird H1 vs Cavity filter?
Yes — there are several practical disadvantages of using a SAWBird H1 (or similar surface-acoustic-wave bandpass filter) compared with a cavity filter in RF front-ends, especially at VHF/UHF, narrow-channel, or…
Can I use cavity filter followed by amplifier to get better effect than SAWBird H1?
Amplifier examples relevant to discussion below of receiver chains that involve amplifier before a cavity filter: Budget amplifiers: Better quality amplifiers: Even better and more expensive amplifiers: Description: Yes —…