Not affected in a noisy place, and can judge at once the polarity of any types of loudspeaker and headphone, suitable in production line.   Can be linked with 3 other kinds of instruments ( Model-152A , 7117C and 7116C ).  Only one  person  is  needed  to make  the  operation,  save  labor  and  time .   Easy  to  learn,  to  operate,  high  reliability.   Has the Positive/Negative indicator extended device, only those Model-139B with serial no. "PLxxxxxxxxx" have this function.  (This extended device must be connected with the Extended Pilot (Model-139BL)) In a HI-FI Stereo System, Loudspeaker & Headphone with a correct polarity is very important.  If the phase ( polarity ) was reversed, HI-FI Stereo's effectiveness would  be seriously affected.  139B is not affected at all in a noisy place, and can judge at once the polarity of the loudspeaker and headphone. 139B can be connected with 152A, 7117K, 7116C to test 4 parameters.  Only one operator is needed ( see left page ). 139B is suitable for loudspeaker system, loudspeaker, multimedia, monitor, headphone  and  audio firms.

Specifications  of  Model - 139B

Pulse Testing Method. Polarity : Pos. polarity :Green LED indicator with beep sound. Neg. polarity : Red LED indicator with no sound. WF : suitable for the woofer. M & T : suitable for the midrange, tweeter & headphone. Ext.1 ~ Ext.3 : For connecting instruments. Sensor : ECM Five selecting switches : Dim. :  28 ( L ) × 9 ( H ) × 21 ( D ) cm. Net Weight : 2.5 KGS.