Some issues, 1943-July 1948, include separately paged and numbered section called Radio-electronic engineering edition (called in 1943 Radionics edition).In order that this need may be adequately filled, International Correspondence Schools offer a modern course in Radio Servicing. Prepared by ... coupon! With the Experimenters (Continued from page 555) blue-black discs are composed of copper sulphide. ... A small angle of heavy copper or brass is bent as in Figure 2 and a hole is bored in the side for the set-screw. ... The meter can be calibrated by comparison with an a.c. meter, but this is not necessary for use as an output meter.