When used together, the SB-300 receiver and SB-400 transmitter could transceive and had many other features of the "S/Line", including crystal bandwidth filters and 1 kHz tuning dial resolution. They could also operate separately (if the optional crystal pack was installed in the transmitter), giving the operator more flexibility in communicating with foreign stations, aka "DX Stations", who were not authorized to transmit within the same frequency ranges as the U.S. stations were authorized to use. The "S/Line" influence was easy to "see" too, in its cabinet styling, tuning mechanism and knobs. But by designing them as kits and using less expensive construction, Heathkit could offer these units at much lower prices. The pair sold for $590 that same year (). The matching SB-200 1,200-watt input/700-800-watt output linear amplifier completed the line for 1965.