In 1946 as Howard Vollum was wrapping up the design of the 511, the Directors of Tektronix decided to introduce a smaller and less complicated product to be able to more easily ramp up a brand new manufacturing organization.  Howard had designed a square wave generator to test his oscilloscope so they introduced this as the Type 101 Video Calibrator.  They built a total of 10 instruments and sold none!  Tektronix first product was a flop.  However, it served its purpose to get manufacturing ready for the Type 511 oscilloscope.  Later the Type 101 Video Calibrator was replaced by the Type 104 Square Wave Generator which had modest sales.

This photo is of Howard Vollum with the Type 101 Video Calibrator on the left and the Type 511 Oscilloscope on the right.  This is the first version of the 511 as noted by the external graticule light and the single sweep speed knob.

Here is a photo of Jack Murdock with the Type 101 Video Calibrator.

The 511 was very well received and the small Hawthorn facility had to add a swing and grave shift and even with 3 full shifts running the lead time stretched out to over 6 months.

The 511 was designed for medium and high frequency work but did not effectively work with frequencies below 60 Hz.  Other weaknesses included lack of sufficient vertical gain, the inability to see the trigger portion of the waveform, and the lack of voltage regulation.  The first enhancement was to add a delay line which could be installed as an option.  The second enhancement was to add voltage regulation to the power supply.  Improving the lower bandwidth and more vertical gain became the basis for the follow-on Type 512 Oscilloscope.

The first advertisement for the 511 appeared in the September 1948 issue of Electronics.

Also in that issue was an article on the transistor called A Crystal Triode.

At the museum we have both the Type 101 Video Calibrator and the first version of the Type 511 Oscilloscope operational and prominently displayed as you enter the museum.  The serial number of the Type 101 is 11461 which represents the date and number of manufacturing: November 1946 #1.  This is the very first product that Tektronix manufactured!

We also know of the existence of #5 which resides in California.

The serial number of the Type 511 Oscilloscope is 441 so it was the 340th product manufactured.

SN 101 was sold to Dr. Archie Tunturi (yes, the man with the 50 channel oscilloscope) and was traded back to Tektronix in 1960.  This article appeared in the February 1961 Servicescope announcing the return of this product to Tektronix.


These two early photos with notes from Frank Hood cast some doubt on whether the original SN 101 was returned to Tektronix (note the Ser # 101 ? legend on the right top edge of both photos).  We simply assume that a number of modifications and repairs were made on the product during the 13 years that Dr. Tunturi used the product.

At the museum we also have a front panel for a 511 that appears to be hand drilled with a serial number 101.  We suspect this was probably a reject panel.

This photo shows a large shipment of 511AD products from the Hawthorne building.

This photo shows a 511A being calibrated and dates from around 1951.

This photo shows the largest single order to date of thirty 511D oscilloscopes shipped to Hughes Aircraft in Culver City, California, on November 7, 1951 from the Sunset plant.  The individuals are (left to Right) Paul Billes, Waldo Johnson, and Dale Holiday.