Science & Nature
1439 sites
Subcategories:
- Astronomy & Space (396)
- Chemistry (8)
- Earth Sciences (26)
- Biology (79)
- Physics (30)
- Mathematics (59)
- Weather & Climate (104)
- Amateur Radio (682)
- Electronics (47)
http://ibiblio.org/modena/hamradio.html
Steve Modena (AB4EL) built this focused ham radio link archive hosted on ibiblio, collecting mailing list digests, USENET archives, and FAQs across specialized topics like QRP, boatanchors, Collins radios, glowbugs, Heathkit, homebrew, and the 160-meter topband. A handy centralized gateway for vintage and low-power radio enthusiasts looking to dig into discussion archives and community resources from the late 1990s and early 2000s.
https://winsystem.org/
The WIN System is a linked amateur radio repeater network based around the KA6WIN reflector, connecting operators across multiple nodes via IRLP and ALLStar technology. The site offers operating tips, member rosters, net schedules, FAQs on repeater use and antenna selection, and information on joining the network or becoming an affiliate.
https://iasindy.org/
The Indiana Astronomical Society is a membership-based club dedicated to amateur astronomy, offering monthly public lectures, access to the historic Goethe Link Observatory, dark-sky observing sites, and outreach programs for students across central Indiana. With resources ranging from a beginner Astronomy 101 crash course to star party event listings and a member collaboration site, it serves everyone from curious newcomers to seasoned sky watchers.
https://cdxa.org/
The Carolina DX Association (CDXA) is a ham radio club based in the Carolinas, dedicated to DX hunting and contesting under callsign W4DXA. The virtual club room offers members antenna calculators, packet cluster links, photo albums, contest resources, roster management, and event payment tools for club luncheons.
http://seboldt.net/k0jd
K0JD's Ham Homebrew Site is a personal amateur radio page by the operator behind the callsign K0JD, focused on homebrewing radio equipment and DIY ham radio projects. The frames-based layout is a classic hallmark of old-web personal pages dedicated to the ham radio hobby.
https://qsl.net/ve3bdb
The ORIGINAL Wireless Set No. 19 Group is a long-running online community dedicated to collectors and users of the WWII-era military radio known as the Wireless Set No. 19, active since 1997. Visitors can explore technical notes, photo galleries, a world inventory of surviving sets, history of the radio in Canadian service, and member submissions covering everything from operating tips to movie appearances.
http://blackcatsystems.com/
Black Cat Systems offers a wide catalog of Windows and macOS software focused on ham radio, shortwave listening, and audio utilities, including tools for SSTV decoding, ACARS, ALE, propagation forecasting, and Morse code training. The site serves as both a software storefront and a hub for amateur radio enthusiasts, with free trials available for most programs.
https://r-knott.surrey.ac.uk/Fibonacci/fib.html
Dr Ron Knott's comprehensive mathematics resource, hosted by Surrey University since 1996, covers Fibonacci numbers, the golden ratio, and their appearances in nature, art, geometry, architecture, and music. Packed with interactive calculators, puzzles, investigations, and dozens of linked pages exploring everything from Lucas sequences to phyllotaxis, this is one of the oldest and most thorough maths sites on the web.
https://pfaf.org/user/Default.aspx
Plants For A Future (PFAF) is a searchable database of over 8,000 plants catalogued by their edible, medicinal, and other practical uses, making it an essential reference for permaculture enthusiasts and herbalists alike. The site covers topics ranging from food forests and carbon farming to rare and unusual perennial plants, with browsable indexes and habitat guides built up over decades by a UK-registered charity.
http://hamradio.de/
Hamradio.de is a German-language community hub for amateur radio enthusiasts, offering a fleamarket for used equipment, forums, contesting resources, club directories, and software. With sections dedicated to awards, DX, and contests, it serves as a comprehensive gathering point for the German-speaking ham radio community.