Designing & Implementing Active BP filter
Shows design procedure and implementation of an active band-pass filter.
http://ite.gmu.edu/~aaljassa/ece464/project.html

TTE
Rf Filters: Specializing in radar application, analog filters, passive filters, uhf filters, vhf filters, antenna filters, differential filters, d/a filters, dac application filters, and adc filters
http://www.tte.com

Clampco Products Inc.
Clampco Products is a leading manufacturer of T-Bolt Band Clamps, Spring-Loaded Clamps, Worm Gear Hose Clamps, and V-Band Couplings used in Truck, Engine, Bus, Off-Road, Marine, Filter, Pump, and Aircraft Equipment.
http://www.clampco.com/

Butterworth Low-Pass Filter
Design of a 5th order Butterworth LP filter using Sallen-Key circuit design.
http://www.ece.uic.edu/~jmorisak/blpf.html

Band Passes.com
Provides backstage-pass type laminates and security badges for bands, events, sound, lighting, and production companies.
http://www.bandpasses.com

Filtronetics Inc.
Filtronetics has Bandpass Filters, Clock Oscillators, Quartz Crystals and RF SAW Filters. Highest quality Custom LC Filters|Microwave Filters|Ceramic Filters|RF SAW Filters|Crystal Filters|Bandpass Filters|Low Pass Filters|High Pass Filters|Clock Oscillators|Quartz Crystals. A valued supplier, designer and manufacturer of electronic frequency products Filtronetics based in Kansas City Missouri.
http://www.filtro.net

Oberlin Filter Company
Manufactures and distributes range of filtration products and equipment. Includes filter cloths, filter bags and cartridges, air filter units, and selection of new and used filter systems. Offers free analysis of wastewater samples.
http://www.oberlinfilter.com/

Superior Boiler Works
Waste heat boilers, Deaerators, Economizers, Feedwater tanks, Boiler Room Equipment, Custom Steel Fabrication
http://www.superiorboiler.com/

Detroit Band Saw Works.
In business since 1987, providing Carbon, Bimetal and Carbide Bandsaw Blades, Coolant and Machinery to the Metalworking and Woodworking Industries.
http://www.detroitbandsaw.com

TV 'helps pupils pass exams'
Watching television could help you pass your exams, say researchers at Reading University.
http://news.bbc.co.uk/1/hi/education/878512.stm