718U Driver & Receiver in K0CXX Transceiver Display

Center left in this display of 30 years of Collins HF transceiver evolution, is a presentation of a 618U-4A Receiver Exciter that covers 2-30 mHz and outputs 200 mW nominal from the exciter. The 618U-4A is on the right in the display of Rockwell boxes and the 514A-7 digital control head is mounted in a custom 718U-12 power supply/audio amplifier to make up a complete system. It is interesting to note that the 618U-4A shares many of the same PC boards with the ARC-138 and also the 651S-1 receiver. This receiver exciter is then used to drive the 204H-1 autotune (servo tuned) 2.5 kW linear amplifier that stands just to the left out of the picture. The shelf units contain Collins HF transceivers ranging in age from the KWM-1 from the 50s to the airborne 718U system.