1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
    Dismiss Notice
Dismiss Notice
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.

Galaxy DX 959 Not Holding Dead Key

Discussion in 'General CB Services Discussion' started by 8113 Northern MN, Jul 3, 2014.

  1. 8113 Northern MN

    8113 Northern MN Active Member

    Joined:
    Aug 9, 2013
    Messages:
    156
    Likes Received:
    16
    Ive been trying to diagnose a strange problem with my DX 959. On AM when trying to check my SWRs I key the mic, it swings up to about 5 watts on the power meter and then instantly drops to zero. Ive tried using the AM Power VR-? to lower the wattage and no matter where I try to set it, when I key up it goes to a certain point but then instantly falls back to zero. Ive been told this means that something is wrong with the AM Carrier but am unsure how to diagnose which part of the radio is causing this issue or which components to start testing for failure.

    Has anyone ever encountered this problem or know how to start diagnosing what is causing it. Thanks!


     

  2. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

    Joined:
    May 1, 2013
    Messages:
    5,123
    Likes Received:
    5,913
    Does the Antenna Warning light come on? Some radios will shut down if the SWR is too high. I don't know if the 959 has that feature.
     
  3. 8113 Northern MN

    8113 Northern MN Active Member

    Joined:
    Aug 9, 2013
    Messages:
    156
    Likes Received:
    16
    No it doesnt. I actually have my President Washington base normally hooked up to this antenna and have know that I have it set at a perfect 1:1. I was just using the not being able to test SWR as a way of showing what I mean by it not holding a carrier/dead key
     
  4. wavrider

    wavrider W9WDX Amateur Radio Club Member

    Joined:
    Jun 2, 2009
    Messages:
    3,375
    Likes Received:
    1,217
    Maybe a bad microphone, wiring or contact in the switch?
     
  5. Robb

    Robb Yup

    Joined:
    Dec 18, 2008
    Messages:
    11,416
    Likes Received:
    3,478
    Does the TX light stay on when the output drops down?
    Any dimming in the channel LED?
     
  6. 8113 Northern MN

    8113 Northern MN Active Member

    Joined:
    Aug 9, 2013
    Messages:
    156
    Likes Received:
    16
    Happens regardless of which microphone we use when testing. There is no dimming at all in the LED and the TX light does stay on when holding the mic even though the power meter shows the quick drop off. Have tested the power meter on my base station and it deadkeys just fine on AM.
     
  7. loosecannon

    loosecannon Sr. Member

    Joined:
    Mar 9, 2006
    Messages:
    3,962
    Likes Received:
    3,143
    do you have an external wattmeter to confirm that the radio is actually dropping out and not just the meter itself?
    LC
     
  8. milkman21218

    milkman21218 W9WDX Amateur Radio Club Member

    Joined:
    Aug 12, 2006
    Messages:
    197
    Likes Received:
    31
    May be a bad driver. I had a Galaxy DX-99V do that.
     
    #8 milkman21218, Jul 4, 2014
    Last edited: Jul 4, 2014
  9. vkrules

    vkrules Sr. Member

    Joined:
    Feb 18, 2012
    Messages:
    1,185
    Likes Received:
    541
    I'd be checking for bad solder joints in the PA section before I went any further.
     
    2 people like this.
  10. Robb

    Robb Yup

    Joined:
    Dec 18, 2008
    Messages:
    11,416
    Likes Received:
    3,478
    Yup.
    To take it another step further, I would get a can of air, turn it upside down, key the radio, give the driver a blast and see if it doesn't come back on. Then, do the final the same way. Might be a thermal failure if the solder joints are OK. In the event that doesn't pan out a failure, you would have to begin troubleshooting further. Since the radio didn't lose the TX light, I would begin looking for poor solder joints in the PA section too.

    Doubtful that the voltage regulator has a problem; but it wouldn't hurt to put a DMM on its output lead and test it under TX load for any unacceptable voltage drop - just to make sure.

    IOW, it is easier to find a failure point by finding out what is still working right. Careful visual inspection of parts can sometimes find problems too, so you might want to get out your magnifying glass.

    BTW - does the radio have any problem with output in SSB mode?
     
  11. hammer0630

    hammer0630 Active Member

    Joined:
    Sep 10, 2011
    Messages:
    474
    Likes Received:
    62
    My 959 had to be fixed basically right out of the box. My radio guy found a cold solder joint bad with in minutes of getting the covers off.
     
  12. Z-MAN 369

    Z-MAN 369 Active Member

    Joined:
    Dec 21, 2012
    Messages:
    148
    Likes Received:
    25
    I use a plastic tuning tool or pencil and push down on the board to find cold soldering around the IC's and etc. Try that while keying the mic?
     
  13. jetman

    jetman Member

    Joined:
    Feb 6, 2013
    Messages:
    47
    Likes Received:
    4
    You have a trickle to gnd somewhere in your tx section. Recheck and make sure a solder joint hasn't leached on to a grounding joint.
     
    #13 jetman, Jul 11, 2014
    Last edited: Jul 11, 2014

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!