NOTE: Tubes marked "SEE NOTE" IAY2, IBH2, IBL2,etc. do not have sockets but can be tested as follows: • Connect 2 pieces of wire to bottom leads or screw terminals on base of tube. • Insert these wires into socket #3, pin numbers 1 and 12 (these pins are on each side of wide space on socket #3). • Connect top cap to cap on tube using another wire if necessary. • Test tube per setup instructions in chart. Do not touch exposed leads while testing INDICATES MULTI-SECTION TUBE For your convenience we have added a foreign vs American cross reference type guide on pages 43 through 49. The foreign tube types listed may be tested on the Model 667 by simply referring to the test information for the American type number.