If you are interested in electromagnetics, engineering, and technology, G3YNH by David W. Knight is a good source of information for electronic components, data analysis projects, and testing laboratories.
He has been involved with numerous electronic, radio, and scientific instrumentation during his career. Awarded a Ph.D. in Microwave Spectroscopy at Bristol University in Radiation Laboratory. Also, a former co-founder of Cameras underwater Ltd. in 1995 – one of the leading suppliers of underwater photographic equipment in Europe.
For your scientific or engineering problem, you can contact him through his email at [email protected] or you may visit his website http://g3ynh.info/ for more information.