Show use uie wood and copper for open circuit jack it will be found that a very good open circuit jack can be made as follows A block of wood inch square 8 inches long Is cut as shown at 0 procure two small pieces of copper and cut one of them 14 4 by L inch and the other J a by 1 inch bend the first piece as shown at A and the seea seca A e i ond one as at B A hole large enough 1 to the plug to pass through it Is bored in the panel exactly in front of the place where the block of wood Is to be nailed the gyp of copper A la Is screwed against the panel and above the hole 10 0 o that when the ping is pushed in it will make a good contact the strip B Is also screwed in place on the block eblock so BO that the up tip of the plu plug Z Is connected to it IL tiie the block Is now fastened in place and the jack Is com plated radio digest |