MFJ 259B Analyzer Question

I know several of you also have the MFJ 259B Analyzer.  I have been keeping mine plugged into the charger wall-wart when not in use.  I now find that I get a LOW voltage reading a few seconds after unplugging it.  The voltage is 13+ as long as it is plugged in….but not conducive to field use.  I assume I need new re-chargeable batteries?  Should you leave it plugged in when not in use?  I found if I didn’t, the voltage would read LOW when I went to use it.  What is your experience on how to best have it ready for use?  How long do the batteries continue to take a charge? TNX & 73!

— John, W1XX 

4 comments on “MFJ 259B Analyzer Question

  1. John

    I don’t use rechargeable batteries and have had regular AA alkaline batteries in for months. It has been at least six months since I used the unit. I just checked and when starting up I see 14.8V displayed. I know its a pain to change them out but I have had good luck and long life with these. I use quality AA brand batteries.

    Good luck

    73

    Jim KS1J

  2. John,

    I have the 269 model and have left it plugged in for months at a time without a problem. I am just plugged into a 15 v power supply for charging. Maybe it depends on battery type and/or enviromentals? Dont know if the unit is smart enough to turn off the charge when the current goes below a certain point or not. If it continues to eat batteries I would look closer at the charging circuitry.

    Good luck

    73
    Rick KI1G

  3. G’morning, John:

    My 259B has the original rechargable batteries installed and it is about 8-10 years old. My typical routine has been to randomly get it off the shelf, turn it ON and check the voltage. When it displays <12V, I plug it in for an over night charge. I do not leave it continuously plugged in to the wall wart. After I read your posting yesterday, I realized that I had not checked the charge lately (meaning I don’t remember when last done). When I turned it ON, it very briefly displayed 12 volts and then rapidly faded to dark. After charging it overnight (I use the MFJ wall wart that came with the 259), it seems to be nicely charged up this morning.

    If you Google something like “rechargable battery charging” you will get move info than you can imagine… and some that you can’t imagine.

    Sounds like you need a new set of batteries.

    73, Ken K3IU

  4. TNX for the responses. I got new rechargeable batteries and all now seems well. BTW: other topic but you W1AW/x chasers, be sure to work W1AW/KH2 in Guam ./. which was a late entry and not listed in QST (I think). 73! — John, W1XX

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