The Digital Display Unit for Elecraft's KPA500

Discussion in 'Amateur Radio News' started by KV5J, Jul 13, 2020.

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  1. KV5J

    KV5J XML Subscriber QRZ Page

    Keith Ennis (KV5J) is proud to introduce the second in his line of Digital Display Units.
    The Digital Display Unit for Elecraft's KPA500.

    HF Amplifiers have always been large and heavy. So placing them near your tranceiver's operating position can be cumbersome. Tube amps need to be close to your operating position so you can tune the amp when changing frequencies. Solid state amps have solved most of the problem allowing amps to be located away from the operating position. Still they needed to be close enough to monitor the displays and readouts.

    So for the Elecraft KPA500 I have designed a compact, easy to read Digital Display Unit (DDU). It allows the monitoring of five crucial readings all at the same time.

    1. Power amplifier's heat sink temperature
    2. Power amplifier's high voltage supply voltage
    3. Power amplifier's current
    4. Power amplifier's output power
    5. SWR that the KPA500 sees at its output

    The DDU measures only 4X4X2 with an easy to read 2 line display that can be located at the operating position and the KPA500 located up to 10 feet away.

    The DDU is designed with the following features:

    Easy to read 2 line display
    No USB or serial cable to computer
    No com port in Windows to manage
    No computer needed
    Plug and Play
    Simply connect the supplied DC power cable to power supply and PC data jumper cable to the KPA500
    Retains all functions of the KPA500 front panel
    All displayed info obtained directly from the KPA500

    The DDU will poll the KPA500 and display PA voltage and PA temperature during receive and transmit cycles. It will add watts, SWR and current during transmit. There is a built in hold time to keep the watts and SWR displayed for a short amount of time after unkeying the amp.

    For more information about the DDU visit: WWW.KV5J.COM

    Attached Files:

  2. RAYAN008

    RAYAN008 QRZ Member

    That seems normal in my opinion. Solid state amplifiers are very sensitive to high SWR's. The best thing to do is to turn the amplifier off, go to all the different bands and tune each band so that the tuner can learn and store the tuned settings. When that is done then turn the amplifier back on and go back to the different bands and operate, then the KPA should not fault. The amplifier only faults because it is seeing the high SWR's when you switch bands and tune. I have two solid state amplifiers and that is how I operate them otherwise I end up with the same response.

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