1-1. GENERAL. 1-2, The VFO, Model 666 is made by WRL Electronics Inc. of Council Bluffs, Iowa. The VFO, model 666 is completely self-contained, including Power Supply and is calibrated for the six meter amateur band. RF output from the VFO is on the fundamental frequencies between 8330 and 9000 KC requiring suitable multiplier stages in the Transmitter to obtain six meter output. Full 170° bandspread of the tuning dial is incorporated for operating convenience. I-3. DESCRIPTION. 1-⅛. The VFO, model 666 is housed in a distinctive cabinet of modern design. Dimensions are 6-5/8" high, 7⅛11 long and 7" vide. Weight is approximately 7 pounds. Among the various features is the CALIBRATE switch on the front panel of the VFO. The switch allows the operator to energize the VFO independently of the Transmitter in order to "zero- beat" a received signal. A new exclusive feature called VFO BANDSPREAD permits very precise tuning of the VFO and eliminates "overshoot" when "zero-beating" a specific signal. RF output is obtained through a cable connected to the rear chassis connector labeled OUTPUT. Length of this cable should not exceed four feet. The VFO may be removed from the cabinet for service and inspection by removing the two top panel screws and the two rear chassis screws. Power requirements are 115V AC, 50/60 cycles, 10 watts.