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.
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