The following codes are recommended as standards to be employed with traveling wave tubes, klystron tubes or crossed field devices. that are equipped with flying leads. It is intended that the insulation of the leads be colored and that these leads be an integral part of the tubes as supplied by the manufacturer. Spaghetti or other nonpermanent means of identifying lead colors should not be used.

Inasmuch as a color code is valuable only if the colors are easily identifiable, it is suggested that EIA Standard GEN-101-A Color Coding for Numerical Values be employed with the color limits as established by Supplement 1 to EIA GEN-101-A, Standard Color Chips.

Since different grids and possible combination of grids may be employed to control current no attempt is made to separate the "anode" or "control grid" from the others. The grids and helices are numbered 1, 2, 3, . . . ,, according to their relative position from the cathode, the lowest number being closest to the cathode. Numbers for grids or helices not available externally are omitted. Where two helices are equidistant from the cathode, the lower voltage helix will be assigned the lower number.