Tektronix 514: When are you from?

Here’s some of my notes about trying to understand a little bit more about the 514, in particular, mine (S/N 948)

The usual questions are:

  • When were they made and for how long?
  • how many different variants were there, and which were visibly different vs which ones were just internal revisions.
  • When is mine from, and which are the correct schematics?  Usually the schematics will indicate a range of serial numbers for which a particular schematic sheet is valid for.

Some of the things I observed in the manuals:

  • the schematics in the BAMA manual for this manual aren’t just raw scans, they’ve been re-composited.  It’s evident elsewhere in the manual as well.  Generally whoever put together the PDF manual did a nice job, but it appears they cropped out the serial number info when assembling the PDF schematic pages.  d’oh.
  • There’s a few pictures in the BAMA manual:
                          SERIES “A”
      With the “serial” field on the bottom left of the unit.  Mine like this, except without the ‘SERIES “A”’ text. (no S/N shown next to “Serial” callout)
      with the serial directly under that. (S/N #5181)
  • Comparing the BAMA schematics to the paper one I bought, I can confirm that the BAMA manual schematics are for S/N 3150 – 3408.
  • There’s a note in my manual that says:
    “Major circuit changes occurred in the Type 514AD oscilloscope at S/N 3409. Numbers in parenthesis indicate the earlier values in the Type 514D oscilloscope.”
    So the ‘A’ version is anything after 3409.  OK great.
  • But, looking at the versions of the vertical amplifier schematic, there is:
    1. “Type 514 / 514D Oscilloscope” S/N 101 – 3149.
    2. “Type 514 Series A Cathode Ray Oscilloscope”, S/N 3150-3408 (same one from BAMA) dated March ’53,
    3. “Type 514 D Cathode Ray Oscilloscope” S/N 3409+, dated March ’56, which has notes about changes in S/N 3650+
  • So it seems like there’s the 514, the 514 series A, and the 514A, all available with or without the ‘D’ for delay line.  The ‘Series A’ seems like it might be the precursor to the plain-old ‘A’ suffix, common of later models, but there’s some inconsistencies in naming conventions across the versions of schematics, so it’s difficult to be certain.  These are the earliest years of the company, so it’s not surprising to see evolution in the documentation.

Observations looking through the catalogs:

  • October ’50 514D is listed for $950.
  • August ’51 514D is listed for $950.  no ‘D’ in silkscreen.
  • March ’52: 514D is listed for $950.  Underside photo shows PS caps identical to mine, but ‘D’ looks like a part of the silkscreen.
  • March ‘53: catalog says there was a 514-D, but there’s no page for it.
  • August ’54: there was -AD only
  • August ’55: gone.

The punchline:

  • Made from 1950 – 1956
  • Mine is from somewhere between ’50 & ’52.  Had to guess I’d say ’51.
  • There were a few different milestones:
    1. S/N 101 – 3149
    2. S/N 3150 – 3408
    3. S/N 3409 – at least 5181
  • some minor changes within the first few hundred are called out in the schematics.
  • They weren’t advertised after ’53, but available until at least ’56.
  • BAMA schematics are incomplete (I’ll upload mine, promise)
  • I wonder if there were examples where the delay line was added post-sale, and the ‘D’ was hand-stamped in, like mine?

6 thoughts on “Tektronix 514: When are you from?

  1. Paul, I had a Tek 514D I bought in 1973 for $150. It was a later production with the flat face CRT. I used it for over 10 years. It was a very good scope for audio work. I loved the fine CRT trace. I upgraded a Tek 465M in the early 80’s for digital work.
    It ran much cooler and quietly. 🙂

    • For one thing it’s a piece of history. 🙂
      It’s really a good scope within it’s limitations.
      The down side is it’s size, weight, heat and fan noise.

  2. At one point, ca 1977, I needed a schematic for my 514D. The lady at the local, Tek place, in San Antonio, was surprised it had still worked. Tried to sell me a later model. I told her it was usually just fine but I needed a print for it. She rolled her eyes, thought for a minute, and said let me look in the microfiche files. I lucked out! She gave me a copy and I was on my way. The problem turned out to be a cap in the HV supply.

    Somewhere along the line I came up with some circuit update mods. They may have been on the microfiche. There weren’t many things involved, just minor stuff. The only one I recall involved removing a few turns from a small inductor. It really sweetened the operation of the trigger and sync controls. Me and that old beast spent many hours together.

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