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Trac TE-122 CMOS Keyer - need schematic

Discussion in 'General Technical Questions and Answers' started by W3HR, Oct 26, 2021.

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  1. W3HR

    W3HR Ham Member QRZ Page

    Does anyone have a schematic for the Trac TE-122 CMOS keyer they can upload, please?

    Thanks for your help.

    de W3HR
  2. N8YX

    N8YX Ham Member QRZ Page

    I have a TE-122 somewhere in my stash. There's a Trac schematic on the 'Net. As I remember it uses a Curtis 8044 keyer-on-a-chip.


    Found a 133. Could you open yours and post a pic of the internals?
    Last edited: Oct 26, 2021
  3. W3HR

    W3HR Ham Member QRZ Page

    Hi, thank you for looking. I saw the 133 drawing, too, but I've found absolutely nothing on the 122 on the web. It has 7 CMOS chips, not a Curtis device. A very bare-bones keyer.

  4. W9GB

    W9GB Ham Member QRZ Page

    The TE-122 sold for $36.50.
    It was an economical TE-133, without the functions: Weight, Tune, and Solid State Keying
    The TE-133 schematic should be identical to TE-122, with 3 features NOT installed.

    As stated in TRAC advertisement, on page 25 of the July 1980 issue of 73 Magazine.
    TTL/CMOS design keyers using TI 7000 / RCA 4000 series ICs were very common in 1970s / early 1980s … before programmable micro-controllers became more common.

    TRAC Electronics Inc.
    1106 Rand Bldg.
    Buffalo, NY 14203

    At the time the Trac TE-122 CMOS Electronic Keyer
    was sold with their iambic paddle "TRAC-KEY".
    Earlier QRZ Technical Forum Q&A, April 2017

    Dennis Doran, WB8WTU (Canfield, Ohio) MAY still have documentation
    (schematic, manual) for the Trac TE-133 keyer.
    Last edited: Oct 27, 2021
    W3HR likes this.
  5. N8YX

    N8YX Ham Member QRZ Page

    Compare those chips to the 133 schematic. That 122 may be a 133 circuit without the weighting controls brought out to the front panel.
    W3HR likes this.
  6. W3HR

    W3HR Ham Member QRZ Page

    Thank you both for the good information! I appreciate the links. I hadn't found anything online about the 122 model, so seeing the 73 ad was helpful. I'll compare the board to the 133 schematic.
  7. WB8DD

    WB8DD Ham Member QRZ Page


    I'm dennis, ex-WB8WTU. Tim, I replied to your email but I'll post the same info here if others are looking for a Trac keyer schematic.

    I've attached the schematic for a Trac TE-133. Basically, all Trac keyers use the same circuitry, with a few added parts between models, for memory and such. The actual keying circuitry is the same for all.

    The TE-122 was one of their first models and it is for grid-block keying only - the older radios. The TE-133 is capable of keying grid-block rigs and solid state rigs. Trac calls solid state keying "direct". With a few added parts, a TE-122 can be made the same as a TE-133. This simply involves adding a switch, a transistor, a few other parts. The TE-133 and most other Trac models already have a switch on the back panel to select grid-block or direct keying. I currently have a TE-122, TE-133 and TE-284 memory model.

    Trac keyers are cheap, basic devices that work as well as any other basic keyer. The are also fairly simple to repair. The old Nye SSK-1-K used a very similar circuit. I hope this information helps.

    Greg - thanks for the referral. You have a great memory and a source of all kinds of useful information.


    Attached Files:

  8. W9GB

    W9GB Ham Member QRZ Page

    When I started in 1970, it was a mix of old vacuum tube keyers (W9TO) and germanium or silicon transistor keyers.
    James Garrett, WB4VVF, Accu-Keyer, published in the August 1973 issue of QST Magazine , was a sensation (started my last year of high school). Photo, housed in a LMB Heeger CO-3 enclosure.
    The commercial market saw several keyers like TRAC (even one from the founder of Digi-Key).
    The TRAC used the RCA CMOS 4000 series (introduced in 1968).

    Good notes on using the 4000 series. of ICs
    • The output pins usually only support a few milliamps of sink or source current.
    • Lots of manufacturers have made these throughout time, so you’ll usually find the chip number with a prefix such as CD4xxx, HEF4xxx, or NTE4xxx.
    • All unused inputs (even from unused gates) should always be connected to either GND or VCC to avoid unnecessary current consumption.
    • Most chips support a voltage supply of between 3V and 15V. Some versions support up to 20V.
    List of 4000-series ICs
    4011 : Quad 2-input NAND gate: An IC with four standard NAND gates.
    Last edited: Oct 29, 2021

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