General Radio Company Develops 535-A scope in 1931 - vintageTEK – A Museum of vintage Tektronix Equipment

General Radio Company Develops 535-A scope in 1931

Posted on: July 5th, 2012 by vtek_admin 9 Comments

I recently obtained a copy of A History of The General Radio Company, published in 1965 by Arthur E. Thiessen Board Chairman of General Radio. The management style and policies of GR as Tek employees later referred to it, were strikingly similar to those of Tektronix.

Furthermore, General Radio, who was a quality leader in instrumentation before Tektronix was born, was also started by an Oregon native named Melville Eastham. Eastham was born on June 26, 1885 in Oregon City, OR. He left school at an early age, but his main philanthropic interest was the Massachusetts Institute of Technology, and many GR employees hailed from MIT.

An interesting piece of history is related on pages 39 & 40. GR developed The Electron Oscillograph Type 535-A in 1931, that was made in two parts. The CRT was mounted separately on a stand,  and the power supply in  a separate cabinet, and was connected to it by a cable. Following the invention of the so-called linear sweep circuit by Professor Frederick Bedell of Cornell University, GR produced the first commercial linear sweep circuit, called the 506-A Bedell Sweep Circuit. It was housed in a separate cabinet, so that a complete oscilloscope consisted of three parts.

The rest of the story, and the development of the monolithic scopes 687-A, and the 770-A to follow, and their dissolution, is explained in the attached .pdf excerpt from the book.

General Radio Scope History

Ed Sinclair

 

9 Responses

  1. Put my snail mail address in and got an Error message when I tried to submit this, chuckle. Well, you didn’t ask for an Email Address!!

    My question is – why did GR not enter the ‘scope market considering all the prework they did in this area?

    • Arnie Frisch says:

      Too early to market?
      Too expensive?
      Unreliable?
      No demand?
      Dumont?

      Radio was the big market then. Why do you think it was named General Radio? Scopes were not big till WWII, where they were needed for radar development. That’s probably where Howard got the idea to pursue this. He was in the signal corps.

  2. I am a student doing a research paper and I would like some information if you can find it in your heart to help me.

    I would like to know the maximum frequency the o-scopes of the 1930’s could read accurately.
    For example:
    The type 535-A in 1931
    The type 687-A in 1934
    The type 770-A

    Any help you can give me would be appreciated more than you can know.
    I like your site and will donate a little when I can because keeping the past history available and alive is more important than most people realize.

    Thanks in advance,
    Greg

  3. Ratib says:

    GR did enter the scope market briefly, but felt that they could not sell the scope as it was “too expensive”. They discontinued developement on it and allowed it to fail due to lack of vision on the potential uses and need for this device. They could have cornered the market as it was a great solution that no one knew they needed yet. This has happened to many companies in the past, including biggies such as Xerox, Kodak and RCA.

  4. Carl Quinn says:

    Having worked on many General radio electronic instruments my opinion is based on the maintenance of these heavy and difficult instruments. Fir example, a great deal of mechanical disassembly and alignment was usually required to return a GR signal generator to normal operation. Too many parts which would make the item expensive. Laboratory instruments such as Bridges, decade boxes and basic electrical standards were good products that stood the test of time and warranted the rugged designs Gen Rad gave them. Competition was way ahead of GR in General purpose test equipment. They operated like a phone company.

  5. Alan Douglas has this to say in his book “Tube Testers, and Classic Electronic Test Gear”:
    “GR attempted to lower the price by combining items in one cabinet, but it was perhaps evident that Du Mont and others would capture the radio-servicing market, and the GR engineers felt that oscilloscopes were unsuitable to accurate laboratory work. There seemed to be no champion at GR to push scopes: the original work had been done by H.H Scott who preferred audio equipment, and Donald B. Sinclair who was soon to make his mark in RF bridges and generators and who eventually became president. Sinclair designed a model 770 scope with advanced features, but the GR executives felt that it was too expensive for its probable market, and abandoned the oscilloscope field.”
    My input here is that scopes did not become laboratory instruments until Dick Ropietquet designed his timebase for the Tek 315, the first sweep circuit that could truly support time-calibration of the X-axis. This is true even of Howard Vollum’s 511 (I have restored one and can attest to this.) Until the Ropietquet circuit, scopes were little more than visual aids, this aligns with the GR view; GR were in the business of precision electronic measurements.

  6. Geoff Bunza says:

    As once the Director of Engineering for GenRad in Concord, MA, I saw the original scope in a display blissfully called the GenRad Museum (at the time, near our metrology lab) and asked an ol’timer (30 plus years ago) about it, and THE question- why didn’t they sell it? Answer back then: the engineers (yes, I said the engineers) didn’t think it would be used much, and didn’t have a wide application. Word had it that they sold the rights (Dumont maybe?). The rest was history.
    On another note, Bill Thurston (GR CEO) once told be of a visit by two gentlemen (Hewlett and Packard) who were starting a company and wanted to understand the culture of GR so they could model their company on what they considered the best engineering company at the time!

  7. chuck house says:

    GR flubbed two significant arenas that they pioneered — the ‘scope was one, and the microwave signal generator or sweeper (basis of the spectrum analyzer) was the other. Both were pioneered by GR during the depression, and both were expensive kludges at the time in a very soft economy. Trying to stay alive, GR also invented the Variac, which found much more ready acceptance, and gave the company some breathing room. When WW II broke out, GR’s key folk (incl. CEO/founder and Chief Engr) went to MIT Lincoln Labs working on radar, etc. and microwave communications. The Navy A-project, designed and built by GR folk, was canceled at war end, and GR elected not to re-acquire it. Hewlett-Packard did so instead, and within ten years had outstripped GR as the revenue and profit leader in instrumentation. GR also felt that the CRTs of the day were inferior to what was needed for a decent ‘scope, and they felt that RCA and DuMont with TV bottles had that technology sort of under control. Howard Vollum, actually with Bill Hewlett’s encouragement, saw an opening, but HP was fully occupied with the unfolding microwave business. Within a decade, Tek had more annual profit dollars than HP even, but they had deprived their reps from a ‘scope when they set up their own sales force. This ostensibly forced HP to ‘go into the ‘scope business’ although it took them years to be credible. GR never really entered either one, and the smugness of Thiessen at the company’s 1965 annual meeting and 50th anniversary is remarkable, given that HP was now 8x as big and Tek 4x as big as GR. I have a paper, entitled “You Should Meet Melville Eastham” written in December 2010, available for the asking, that delineates this. The upshot is that all three companies — GR, HP, and Tek — owe much of their culture to the original approach that Eastham instilled. We all were lucky!

  8. John Minck says:

    In my Narrative History of HP, I reproduced about 10 pages of Fred Terman’s Oral History of his time at Stanford. Terman made the connection between Hewlett and Packard and Melville Eastham a founder of GR. Terman was personal friends with Eastham and asked him to give starting out advice to Bill and Dave.

    John Minck

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