Smith splicer, with a can of Edivue Diluent (developer) 3M Scotch Brand Aluminized Video splicing tape, and in the background, two 90-minute rolls of 3M Scotch Brand 400 recording tape. Missing from this photo, is the Trimming knife (which included a rubber roller), Trimming block and a pair of cotton gloves, such as those used by film editors, to handle the tape.
 


Figure 3 from the Smith Splicer manual. This is an exaggerated view of what the "developed" video tape looks like. The area inside the circle is what you see looking through the 40-power microscope.
 
The manual's "Recommended Procedure for Splicing TV Magnetic Tape" includes 37 detailed steps needed to make the splice.
 

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Scope Trace

An alternative to the traditional Smith Splicer, replaced the microscope with an oscilloscope and two magnetic pickup heads. These heads are located so they "read" the edit pulse on either side of the splice.   The tape was then positioned, so that the trace was in the center of the scope. This located the spot on the tape where the cut was to be made.   This technique eliminated the need to develop the tape, and to some extent, reduced the amount of tape handling required in making the spice.   Note: The greatest danger in tape handling, is the likelyhood of creating dropouts.