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)
https://thesignman.com/qsl
The SignMan of Baton Rouge offers QSL cards specifically designed for the 10-10 International Net amateur radio organization, with multiple card styles including standard and eyeball business-card sizes. Pricing, ordering information, and design previews are all presented here, alongside links to other SignMan products like name badges, magnetic signs, and Skywarn items.
https://perezmedia.net/ceruleanarc/storm-chase-sum.html
Jeremy Perez's Cerulean Arc is a detailed storm chasing blog featuring firsthand summaries of tornado intercepts and severe weather events across the American Southwest and Great Plains, stretching back to 2009. Each entry combines narrative field accounts with meteorological analysis, road network strategy, and storm photography, making it a compelling read for weather enthusiasts and chasers alike.
https://www.qsl.net/k6eag
The Hayward Radio Club (K6EAG) is a non-profit amateur radio club serving the San Francisco Bay Area's East Bay community, offering member meetings, emergency preparedness drills, licensing upgrade classes, and access to 2M, 6M, and 70CM repeaters. Incorporated in California as an educational foundation, it provides a hub for ham radio enthusiasts in the Hayward region.
http://sten.astronomycafe.net/the-astronomy-cafe
NASA scientist-educator Sten Odenwald has maintained this astronomy education hub for over 20 years, filling it with popular essays on cosmology, black holes, space travel, and the weird corners of nature. Visitors will find Q&A resources, blog posts on recent space discoveries, and details on his published books including a photo-filled history of space exploration through 100 iconic objects.
https://hamexam.org/
HamExam.org has been helping aspiring ham radio operators pass their licensing exams since 2003, offering completely free practice tests and flash cards for Technician, General, and Extra class licenses. The site covers all current FCC question pools and includes account tracking so users can monitor their progress on problem areas.
https://heavens-above.com/?Lat=35.60
Heavens-Above, developed by Chris Peat, provides real-time satellite tracking and customized astronomical predictions based on your geographic location, including ISS passes, Starlink visibility, and deep space mission data. The site also offers interactive sky charts, solar eclipse information, comet and asteroid tracking, and a full satellite database spanning dozens of spacecraft.
https://w3eax.umd.edu/
W3EAX is the Amateur Radio Association at the University of Maryland, a student club with roots going back to 1933 and an ARRL-affiliated callsign. Their well-equipped shack includes HF, UHF/VHF, Amateur Television, and satellite gear, plus a full electronics workbench for hands-on radio experience.
https://w6ze.org/
The Orange County Amateur Radio Club (OCARC) has been serving Southern California ham radio enthusiasts since 1934, making it one of the longest-running ARRL-affiliated clubs in the region. Visitors will find meeting schedules, club nets, emergency communications info, a newsletter archive, VE testing sessions, and resources covering everything from satellite communications to digital modes like FT8 and D-STAR.
https://eskimo.com/~oolon/wwdxc
The Western Washington DX Club (W7DX) is a ham radio club based in the Pacific Northwest, offering members access to DX bulletins, contest calendars, propagation forecasts, QSL bureau info, and a newsletter called the Totem Tabloid. The site includes meeting announcements, officer rosters, club bylaws, and links to regional ham radio clubs and resources throughout the 7th call area.
http://circuitsage.com/newroutine.html
Circuit Sage offers free design routines and tools for analog and RF circuit engineers, covering topics like PLL design, LNA/PA design, impedance matching, bandgap references, and transmission lines. The site provides Mathcad-based calculation routines that serve as practical references for IC and wireless circuit design work.