the pilot able to select the desired transmitter and control the mode (Voice, MCW, CW) at the transmitter control box. The receivers were tuned at the pilot's control box by electrical cables and long mechanical tuning shafts, allowing remote control of power, mode, frequency, and volume. AN/ARC-5 set composition and control differed markedly from the earlier systems. Three-unit receiver racks were still predominant, but the receiver line-up was quite different. One receiver would usually be a R-4A homing receiver, another the VHF R-28/ARC-5, and the last an MF/HF communication receiver. The transmitter rack would hold a VHF T-23/ARC-5 and an MF/HF transmitter corresponding to the MF/HF receiver. Frequency-stabilized versions of the AN/ARC-5 communications receivers usually have a yellow circle-S stamped on the front panel. Such receivers were not remotely tuned by the pilot, but were instead lock-tuned to the associated transmitter's frequency before take-off. AN/ARC-5 navigation receivers are not so stabilized, and if installed in the rack a control that allows remote tuning is required. Because of these characteristics, AN/ARC-5 close equivalents to the control boxes of the ARA/ATA and SCR-274-N are rare or never existed. The most common AN/ARC-5 receiver remote control box is the C-38/ARC-5, which allows control only of audio volume of the VHF and MF/HF receivers. No power, mode, or frequency controls are present. The C-38 also has controls for the R-4A homing receiver. A common AN/ARC-5 transmitter control box C-30A/ARC-5 has controls for selecting the MF/HF transmitter or the VHF transmitter, and a switch to select the channel for both the VHF transmitter and receiver. Mode controls are normally set for voice and covered. The typical AN/ARC-5 three-receiver, two-transmitter installation reflects system capabilities that are quite sophisticated compared to the earlier systems, allowing VHF homing, four channel VHF-AM communications, and one channel MF/HF-AM communications. All unnecessary controls have been eliminated to simplify operation of this more capable system. Aircraft Radio Corporation, along with Stromberg-Carlson, made most AN/ARC-5 units except for the Western Electric VHF units. Legacy The AN/ARC-5 certainly represents the climax development of the pre-war MF/HF command set. But its VHF AN/ARC-5 set and the AN/ARR-2 homing adapter presaged a move toward higher frequencies. During World War II, the Navy began a slow movement toward VHF-AM for command functions in theaters where it made sense, beginning with the Western Electric WE-233A commercial airline set which was later re-designated the AN/ARC-4. By 1943 they began