Curtis EK-480 with IM-480 Keyer

Discussion in 'Straight Keys - CW Enthusiasts' started by NT4U, Feb 24, 2018.

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  1. NT4U

    NT4U Ham Member QRZ Page

    I picked up a working Curtis EK-480 Keyer with the IM-480 (Instructo-memorymate) unit at the Orlando swap. There appears to be some issues with the IM unit. Does anyone have a copy of the operations manual and or circuit diagram for these units? or maybe a link?
    Any assistance would be greatly appreciated.
    Thanks & 73

    Alan NT4U
  2. N6KZ

    N6KZ Ham Member QRZ Page


    I also need a manual for my Curtis EK-480 Keyer. Did you obtain a manual for yours and, if so, is it possible for me to obtain a copy of yours?

    Thank you,

    Jim Zimmerman N6KZ
    Prescott, AZ
  3. K7MEM

    K7MEM Ham Member QRZ Page

    I did a lot of searching, but I can't find much of anything for that keyer.

    That means it's time to open it up and reverse engineer it. There is a 8044 Series Keyer-on-a-Chip: Application Note that should give you lots of information about the Curtis chip. You don't have to add much to access all the functionality. You might also look at some older issues of the ARRL Radio Amateurs Handbook. The 1979 issue has a keyer using the Curtis chip.

    I had a similar problem with a MFJ-482B Grandmaster Memory Keyer that I bought at a ham fest. There was information on similar units, but nothing on the MFJ-482B. I opened it up and reverse engineered it. Some time later, another ham sent me a copy of the manual.

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