The instrument simultaneously injects fast rise time low voltage repetitive surges on each collector ring. The reflected wave forms are displayed on a dual trace scope. If there are no anomalies the reflected wave forms will be identical. The wave forms will be different if shorted turns are present. The instrument can be used with analog or digital dual trace scopes that have bandwidths of 20 megahertz or greater and a voltage resolutions of 0.5 volts to 2.0 volts per division. The instrument case is designed to carry the instruction manual and all necessary test leads.