IC-7300 Clock Battery Failure

Discussion in 'Radio Circuits, Repair & Performance' started by NZ4J, Jun 25, 2018.

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  1. W1TRY

    W1TRY XML Subscriber QRZ Page

    Telling time? :rolleyes:
    KA9JLM likes this.
  2. W9WQA

    W9WQA Ham Member QRZ Page

    ill look at using an "extra" , "tanker" batt to feed the internal one.
    one thing is certain: if i ever remove the original, i would never replace it!!
    i will run one wire out where i can work with it, not the board.
  3. W9WQA

    W9WQA Ham Member QRZ Page

    still lookin? wondering?, see "THE FIX" thread.
    no soldering,no mess with icom battery,2 parts...inside...done

    btw, im curious. i cant trace the schematic to see where the 3 v charging comes from.
    its not needed for fix but id like to know how it gets there with rig off...
    Last edited: Dec 20, 2019
  4. W9WQA

    W9WQA Ham Member QRZ Page

  5. KA9JLM

    KA9JLM Ham Member QRZ Page

    It comes from the Always On 5V regulator.
  6. W9WQA

    W9WQA Ham Member QRZ Page

    i saw 3v at the 3k resistor fed from an ic and a line labeled 3v?.
    ill double check. seems like a lot of stuff for only 25ua.
    i tested at 7v input, it still read about 10 ua so i "assume" it would still charge there. ill see when i get the batt.
  7. W1RNY

    W1RNY Ham Member QRZ Page

    I just picked up a 7300 and 9700 after having been out of the hobby for many years.
    I have to say after reading this thread I am considering returning both radios to HRO.
    This has to be one of the most absolutely stupid design flaws I have run into.
    I am 67 years old....having grown up in NYC, so there is very little that shocks or surprises me.

    But, this. I am finding it hard to believe that ICOM in this day and age with decades of experience with BIOS batteries, they could make such a design decision. It is not only the clock but that the clock function makes the use of the transceiver problematic.

    Why hasn't ICOM responded to this and made changes since the radio came out?

    Knowing that switching supplies generate "dirty" RF, despite a footprint that is really too large for our condo, I purchased a 30 amp, adjustable voltage Astron. (I told my wife that it will do double duty as an exercise weight.)

    I really do not want to have to leave the Astron on all the time

    Question: Will the battery charge when the unit is simply supplied power but not turned on?

    The reason I asked is that it occurred to me that another solution would be to use a much larger rechargeable battery attached to the unit. (I want to be able to run both the 7300 and 9700 using relative QRP during portable operations when the XYL and I take a xcountry trip in the spring. So, I was going to purchase one anyway.

    If the battery is charged when the unit is off, the current drain could be measured to see if this solution is possible using a battery of reasonable size.
  8. W9WQA

    W9WQA Ham Member QRZ Page

    more info in the "fix" thread
  9. KA9JLM

    KA9JLM Ham Member QRZ Page

    You should post a link to it here. ;)

    It is hard to keep up with two.
  10. W9WQA

    W9WQA Ham Member QRZ Page

    7300 clock batt, "THE FIX"
    KA9JLM likes this.

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