Polarity Tester 139b Loudspeaker Tester Model-139b

Even in a very noisy environment, Model-139B still can determine quickly and precisely the positive and negative polarity of a loudspeaker headphone receiver, and every single unit in a loudspeaker system. Model-139B also includes 3 sets of external input terminals and selector which can be used to combine with other instruments, to measure the other features of a loudspeaker simultaneously. It is quite suitable for 100% Q.C. testing for loudspeakers in the production line.

Technical specification:
(1) Pulse measuring method.
(2) Polarity indicator :
(a) Green indicator: Positive polarity with beep sound.
(b) Red indicator: Negative polarity with no sound at all.
(3) Five touch switches :
(a) WF range: Suitable for measuring the polarity of the woofer.
(b) M & T range: Suitable for measuring the polarity of midrange and tweeter.
(c) EXT.1 to EXT.3 : Used to select the instrument connected to the external input terminal.
(4) Model-139B can be connected with Model-7116C, to measure the buzz, rattle of a loudspeaker. Only one operator is needed.
(5) Measuring distance: 2 to 4 Cm. from the center point. of the dust cover of the pre-measure loudspeaker.
(6) Measuring sensor: Uses ECM.