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Thread: TS480HX transmitting issues

  1. #1

    Exclamation TS480HX transmitting issues

    Recently from a friend I purchased TS-480HX radio.
    I connected to my longwire antenna and MFJ 971 ATU.

    I must say I had 2 PSU's capable of giving 20Amps and both are used on my Icom 706 MKII radio without any problem.
    When in ssb mode max given current that is shown is around 10-12 amps so I suppose both psu's are working well (Icom 706 MKII).

    In RX mode it works well, good sensitivity, but...
    When in TX mode , TS480HXI had issue of resseting of unit during or after TX (SSB mode).
    I tried everything and all I can get better is not resseting up to 60W, one PSU as a power supply and only in "setting mode" where I set my antenna SWR.
    When CQ-ing or making QSO it reset it self.
    I have video where it can be seen. First seconds are with bad adjusted SWR from my ATU and after that SWR is adjusted so it can be see that SWR is low.
    Any one having this issue with it's radio ?

  2. #2
    K7KBN's Avatar
    Join Date
    Jul 2008
    Bremerton WA USA


    Try using an automobile battery (around 12 - 13 volts) to see if the radio faults. It might even be a good idea to have the vehicle running to keep the battery from discharging too much.
    Pat K7KBN
    Semper ubi sub ubi.

  3. #3


    I think K7KBN's suggestion will prove the radio is just fine. A quick look online shows that is a 200w radio with split finals having separate power supplies and that the radio requires 41A of current (if using one power supply to run the radio). Id bet its shutting down to protect the radio from damage. I think you will need to pigtail both DC1 and DC2 when using one PSU or if you are using two, make sure they are within a volt of each other.
    Last edited by brandon lind; Sat 11th Jan 2020 at 19:28.

  4. #4


    That looks like a low power reset to me as well.

  5. #5


    I think I have found the problem: It is common current returning from antenna.

    I made tests at original site (my friend that gives me this radio) and we made tests with:
    - 25amps power supply
    - G5RV antenna
    - LDG auto tuner
    - set to 130W CW and SSB on 80m and 40m (made couple of qso's as confirmation radio works well)

    and everything goes well.

    Now I am preparing 1:1 curren air choke (ugly balun) and new antenna - longwire with 9:1 balun. My prevoius antenna was random wire with 49:1 balun.
    I use MFJ 971 manual antenna tuner.

    Also I have to re-check my two psu's for possible faults (I doubt there is but to re-check).

    73 de Z34PEC

  6. #6


    It appears to me that the TS480HX Power Amp may be going into Protect Mode.
    I recall two times of extended use ( during long contest operation , hours , hours and Higher SWR Tuning scenarios ), I have seen the TS480HX base unit get warm, resulting in higher Fan speed. Then the Base Unit shuts the Radio down , with a Power Down : Power Reset on its own. This was during Summer month’s higher room temps / high humidity.

    If it is a used Radio - may suspect the Finals or Power Amplifier protect circuit.
    Last edited by AJ4UY; Fri 21st Feb 2020 at 05:02. Reason: Environmental

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