Heathkit had been including schematic diagrams of nearly every major kit in its catalog since 1954. In addition, the DX-100's listing contained two interior pictures and a block diagram. The 15-tube design could transmit either CW or AM (voice) with 100 to 140 watts output on all seven short wave amateur bands. It had a built-in power supply and VFO, and weighed 100 pounds. Priced at $189.50, it was expensive for the time (), yet undercut other amateur transmitters having similar features. It became quite popular.