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Blown Up Anytone AT-6666

Discussion in 'General CB Services Discussion' started by TheRATT, Oct 11, 2018.

  1. TheRATT

    TheRATT Member

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    Ok, here is a fun one!



    I've had an AT-6666 since March and have used it at home and in my mobile. It has worked flawlessly with stock mic, power mic, 5/8-wave Sirio in the mobile and my dipole at home at all power rates.

    Last Friday when driving home from work, when I keyed up it showed SWR at 17:1 (it was 1:1 in the mobile) and then it died.

    I was wondering what caused it? It wasn't hot out, the Mic was turned up half way. I'm having it replaced for free but don't want to make the same mistake again -- unless this is just how they work... the just randomly blow up at some point.

    Suggestions?
     
    rabbiporkchop likes this.

  2. w9cll

    w9cll W9WDX Amateur Radio Club Member

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    Well they are cheap quality radios.
     
    rabbiporkchop and sp5it like this.
  3. TheRATT

    TheRATT Member

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    Well, they may well be, but still there has to a more accurate cause to why it failed. RF Power too high?

    Power mic?

    Mobile running?

    Fro some reason the SWR/Power safeties didn't kick in.
     
  4. Robb

    Robb Yup

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    First thing I would check is the integrity of the coax from the radio to the antenna including the PL-239 connector for continuity or shorts. Test it and wiggle everything to see if anything changes with your DVM meter. I suspect the coax/antenna system has an open circuit/no load situation.
     
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  5. TheRATT

    TheRATT Member

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    Thank you! I'm gonna give it a go tonight and then shoot off for a replacement if I can't find it. I've already got the company to replace it so it can't hurt to see if I can save myself some shipping!
     
  6. w9cll

    w9cll W9WDX Amateur Radio Club Member

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    Yes all of the above. Honestly, it was probably just a component failure.
     
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  7. Rwb

    Rwb Active Member

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    I like to use my electric tester and see if i got a short.
    Glad they are replacing it
     
  8. Robb

    Robb Yup

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    I do not recommend blindly buying something w/o testing first. You are looking for 'no load condition' on the radio. The antenna is supposed to be ~50 ohms @27mhz. If you have access to an antenna analyzer I would recommend doing that first, since the result will define the problem instantly if there is one.

    When a radio, regardless if it has a mosfet or bipolar type final transistor, doesn't have a continuous load on its output (50 ohm antenna or 50 ohm dummy load) when transmitting, it will show a bad SWR and ultimately burn up the final transistor. #1 cause to blowing a final in any radio. All it takes is if the coax has been cut or severely smashed to cause a lot of headaches. SO the issue may be a munched coax or a bad PL connector to the antenna. Not easily noticed unless monitoring. Either way, it can create a 'no load'condition' and the final transistor will fry. Cheap jumper coaxes are also notorious for causing problems like this too. Check all of it unless you want to continue to play tag with the store that sold you the radio.
     
    #8 Robb, Oct 11, 2018
    Last edited: Oct 12, 2018
    Shadetree Mechanic, Tallman and Rwb like this.
  9. 743SEPA

    743SEPA New Member

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    Did you get it replaced through Anytone or who you bought it from? I can't get an answer from from their tech support to some questions I have.
     
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  10. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

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    AnytoneAT-6666.jpg Well. I found a good looking inside pic, so I'm kinda curious to know if this board looks like what you got or have they made even more changes to the design?

    The SWR meter detector is the Toroid looking thingy near the bottom right - the Coax passes thru the center.

    I can see several areas where a major fail can cause a catastrophic fail - but you have been using it in both base an Mobile operations - so that means a lot of thumbscrew work - any possibility that the thumbscrews are causing the flexing and imminent failure of that board - I mean take a look at that back panel...I worry...
     
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  11. M0GVZ

    M0GVZ Sr. Member

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    Do you use a magmount? If so then it was likely the crushed coax where it comes into the vehicle which caused the failure. Just because it doesn't meter a dead short with a multimeter doesn't mean it isn't causing problems. The 50 ohm impedance of the coax is created by the ratio of the diameter of the outer skin of the core to the inner skin of the braid. Alter that spacing, such as when you crush the coax when you shut the door on it, and you alter the impedance of the coax. You can then end up in the situation where you've crushed the coax to half its thickness where it shows no short with a DC multimeter but appears as almost a radio killing dead short to RF giving a high SWR.

    Just one of the many reasons not to use a magmount for anything but the most short term temporary installations such as a hire car.
     
  12. TheRealPorkchop

    TheRealPorkchop Certified Sith Pimp

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    Or use a bulkhead or drill a hole, though still not the most optimal choice for an antenna. But I’ve had that very thing happen with my own antenna and a lesson was learned.
     
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  13. Rwb

    Rwb Active Member

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    I run my mag mount coax in through rubber gromments in firewall.i make sure of no pinch points or extra sharp bends routing coax.never was keen to the slam a door on coax idea
     
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  14. rabbiporkchop

    rabbiporkchop Well-Known Member

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    FPQ13N10's aren't exactly known for reliability. Time to upgrade. Couldn't hurt to have some beta matched spares.
    [​IMG]
     
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  15. TheRealPorkchop

    TheRealPorkchop Certified Sith Pimp

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    Come on now, really??
     
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