Tektronix first curve tracer was the 570 and was introduced in 1955 to display the characteristic curves for tubes. These curve tracers are highly sought out by audiophiles for matching tubes and command high prices. All subsequent Tektronix curve tracers were to display the characteristic curves for transistors.
Transistor curve tracers are marvelous instruments. They feature two sockets for devices and a switch to select between them. This can be used to match devices. They display voltage-current curves so can be used to show the characteristic waveforms for bipolar and unijunction transistors and FETs, diodes, tunnel diodes and zeners, SCRs, resistors, and other devices. They can be used to check capacitor leakage, restore and charge rechargeable batteries, bring up and help locate shorts in PCBs, and a variety of other troubleshooting tasks.
The Measurement Concept book Semiconductor Device Measurements was first printed in 1968 and is devoted to curve tracer measurements on a variety of devices. This book is available used in our web store or may be purchased as a PDF file on CD.
The museum has three curve tracers on display and one in use. The first curve tracer for transistors was the 575 which was introduced in 1957 and had a long production life until replaced by the 576. The 575 was finally phased out in 1972. John Kobbe had a instrumental role in the development of both the 570 and 575 curve tracers.
The 576 curve tracer is not on display in the museum but is used for repairs in our restoration room. The 576 was introduced in 1969 and features a novel display readout using fiber optics and incandescent bulbs to display key operating parameters directly (see Fiber Optic Readout for more information). These readouts allow setup information to be captured in a screen photograph for future reference.
The 576 can deliver 220 watts of power to the device under test with voltages as high as 1500. There was a protective cover over the device under test with a safety switch for elevated voltages. Most of the protective covers have been removed as on this curve tracer. The 576 was phased out in 1978.
The 577-D1 (with a storage CRT) was introduced in 1974 and does not have the direct readout features. There was also a 577-D2 without the storage CRT. The 577 can test devices up to 1600V and up to 10A at the lowest voltage setting. Both models were in production until at least 1985.
The museum also has a 5CT1N plugin curve tracer for the 5000 series scopes. This plugin was introduced in 1972 and was in production until at least 1985.