NOTES TO THE INSTRUCTOR ON THE ELECTRONIC 

 EQUIPMENT USED IN EXERCISE XVIII 



APPENDIX B 



The most satisfactory equipment now avail- 

 able for teaching electrophysiology to students 

 at any level is the Tektronix "160 series" of 

 instruments, manufactured by Tektronix, Inc., 

 Beaverton, Oregon. This equipment, designed 

 originally for teaching medical school neuro- 

 physiology, has proved to be extremely depend- 

 able, easy to operate, and of high research 

 quality. For the experiments chosen here, we 

 purchased the following pieces of equipment 

 (prices as of early 1961): 



Type 360 Tektronix Indicator Unit at $250.00 



at $125.00 



Type 762 Tektronix Waveform 

 Generator 



Type 161 Tektronix Pulse 



Generator at $125.00 



Type 160A Tektronix Power 



Supply at $175.00 



Type 122 Tektronix Preamplifier at $130.00 



Type 125 Tektronix Amplifier 



Power Supply at $250.00* 



The waveform generator provides the proper 

 voltage to drive the horizontal sweep (100 ^lsec 

 to 10 sec) of the electron beam of the indicator, 

 and also to trigger the pulse generator. Pulse 

 stimuli of to 50 volts amplitude and 10 /isec 

 to 0.1 sec duration from the pulse generator are 

 therefore always synchronized with the sweep 



* One 125 preamplifier power supply serves for 

 four setups. 



of the horizontal beam of the indicator, thereby 

 facilitating the observation of electrically evoked 

 responses. 



The 122 preamplifier (a-c, 0.16 cycles to 40 

 kilocycles) provides amplification of 100 or 

 1000, and together with the 360 indicator unit 

 provides a sensitivity of 50 /xv/cm. 



The 160A power supply provides the required 

 voltages and currents for the 360 indicator unit, 

 the 162 waveform generator, and the 161 pulse 

 generator; while the 125 preamplifier power 

 supply powers up to four 122 preamplifiers. 

 The need for batteries with this equipment is 

 therefore eliminated; all the current needed is 

 provided by a 110- or 220-volt a-c wall outlet. 



The instruments may be attractively and con- 

 veniently mounted in frames of standard rack- 

 mount dimensions, and either placed in open 

 racks or cabinets. We have frame-mounted the 

 360 indicator, 161 pulse generator, 162 wave- 

 form generator, and 160A power supply to- 

 gether; and with a rack-mounting model 122 

 preamplifier housed our instruments in a Bud 

 cabinet (model CR 1736, Bud Radio Co., 

 Cleveland, Ohio). Each 125 amplifier power 

 supply is placed conveniently to four such 

 setups, and connected via cables with the 

 amplifiers. 



The nerve chambers which we have found 

 satisfactory were purchased from the Harvard 

 Apparatus Company, Dover, Mass. ($13.75 a- 

 piece). The wick electrodes used for recording 

 the electrical activity of the Limulus eye were 

 designed for this experiment, but undoubtedly 

 would be satisfactory for any experiment in 

 which wick electrodes were required. 



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