These jacks are in all Model 7 Series Polygraph Driver amplifiers, 7P122, 7P511 amplifiers, and 8&9 Series EEG amplifiers. They are miniature 2-terminal, single-ended phone jacks with a single "hot" terminal and a ground terminal. These jacks accept a standard 0.141" diameter mating phone plug. We stock the Switchcraft #780 plug (PLU-780), and also offer an 8-foot shielded cable having a right angle molded plug at one end and the other end unterminated. (#4336) DO NOT ATTEMPT TO PURCHASE OR SUGGEST THAT A MATING CONNECTOR CAN BE OBTAINED FROM RADIO SHACK. These foreign plugs do not fit properly.

The J5 is an Input and is intended to accept 1 volt RMS (2.8 V peak to peak). NOTE: WHEN THE PLUG IS INSERTED, ALL FRONT PANEL CONTROLS ARE INOPERATIVE. The only controls available are on the rear chassis of the 7DA,7P122,7P511; one for positioning (J5 BLP) and one for sensitivity (J5 SENS).

The J6 is an output and provides 1 volt RMS (2.8 V peak to peak) corresponding to full scale pen deflection (either 30 mm or 50 mm with 811G or 711G oscillographs). The signal is available independent of the chart paper. The low freq response is controlled by the low filter on the preamplifier; the high is controlled by the high frequency filter.

With an upward pen deflection, the signal is negative (See Tek-Tips Polarity Issues). Note the use of the J6 output for BrainTree systems.

Contrary to normal logic, the J6 output precedes the J5 input in the amplifier chain, so it is not possible to input to J5 and take the signal out of J6 as some try to do. It is possible to input to J5 and take the signal out of J7 (Model 7DA,7P122,7P511) or J10 (Model 8 and 9). There are front and rear panel J5/J6 jacks on the 7DA,7P122,7P511 amplifiers making it possible to cable from the rear panel and connect to two devices simultaneously.

A nice feature of the J5/J6 arrangement is the possibility to output a signal from the J6 jack, manipulate it with external devices (filters, etc.) and connect it back into the J5 jack of the same channel for write out on paper. The original intent was for the simultaneous recording and playing back using instrumentation tape recorders. This technique provided a means of monitoring the data being placed on tape, since the playback signal was that signal taken from the playback head of the recorder.

Note that there is a rear panel "ALL CHANNEL J6 OUTPUT" (SRJ6) connector on most Model 8 and 9 EEGs, and all new Model 7 series polygraphs. We can retrofit this output on Model 7 series with the 7SRJ6 unit.