A2 Global Electronics  Source of discontinued/hard-to-find semiconductors, ICs
Active Components  Canada
AF4K - Radio Crystals  Large selection
Allied Electronics
Barker & Williamson - B&W  Antennas, coils and accessories for HF radio
Battery Clerk, Canada  Replacement batteries for Two Way Radio
Budwig  Antenna insulators, dipole feed points, plastic and rubber feet (great for Heath SB-line)
ByteMark Corp. - U.S.A.  Amidon amateur products, W2FMI baluns, and more
Collins, Drake & Misc Parts  Harbach electronics
Coilcraft  Inductors, EMI / RFI filters
Cornell-Dubilier Capacitors
Creatron Inc.  Arduino, Components, Hardward, Tools, etc. (Toronto, Ontario)
Digi-Key  Free catalog
Electro Sonic, Inc.
Expanded Spectrum Systems  Crystals - vast offering of frequencies
Fair Radio Sales  Good source of tubes & other radio parts
Far Circuits  Circuit boards for amateur radio, and hobby enthusiasts
Fletcher Electronics (VA3NRF)  Vintage Components, Transistors, Chokes, Resistors, IC's, etc.
Giga-Tron  Coax switches, microwave components and more
Hammond Manufacturing  transformers, chokes, electronic enclosures
Intel
International Radio - INRAD  Crystals, crystal filters, and more
Intersil  High performance analog semiconductors
Jameco
Just Radios  Good source for high voltage capacitors and carbon resistors
Kanga USA
Keystone  Electronic hardware - Free catalog
Mini-Circuits  Frequency mixers, amplifiers, filters, application notes, and more
Motorola
Murata  Inductors, trap filters, variable inductors, etc.
NTE Electronics  Replacements for more than 3000 electronic components
Newark Electronics  Free catalog on request
Ontario Surplus  antenna masts, cable, manuals, misc. - focus on amateur radio
Palomar Engineers  Ferrite beads & cores, balun kit, RFI kit and more
Peter Dahl Transformer Company
Philips Semiconductors
R.F. Parts Company  RF semiconductors, tubes, and much more
RP Electronics - Canada  baluns, torrid coils, kits, tubes, and much more
Richardson Electronics  RF & microwave semiconductors
SND Tube Sales  Tubes, sockets, tube testers and more
Texas Instruments  Semiconductors
Toko  Inductors, filters (ceramic & helical), GPS antennas
Toshiba  Semiconductors, tubes, RF & microwave