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Is a Magnum 257HP an overkill for a Texas Star 667V?

Discussion in 'General CB Services Discussion' started by Turbo T, Feb 21, 2013.

  1. Turbo T

    Turbo T Certified CB Rambo

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    Thought I'd ask. I'm wanting to get an amp for my 257HP. I see the 667V is a 500/650 watt amp. But isn't the knob on the front so you can adjust the sensitivity of the input power?



    Or would my 257HP be too much for a 667V?
     

  2. Robb

    Robb Yup

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  3. Bundy

    Bundy Tired and broke

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    That is a great link Robb, thanks
     
    #3 Bundy, Feb 21, 2013
    Last edited: Feb 21, 2013
  4. 2RT307

    2RT307 Sr. Member

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    Yes, it is overkill. Keep the variable out of the mix, and go with the DX500 to run with that rig (or any other one you want). Will make a nice setup with strong output.

    73,
    RT307
     
  5. Turbo T

    Turbo T Certified CB Rambo

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    Ok then is the 667V really only good for a 4 watt rig? Also when it was showing the 20 watts on that Texas Star page, is that modulation power or carrier power.....? Also what's so bad about the variable powered amps?
     
  6. space cowboy

    space cowboy Quack Quack

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    just set it for enough dead key to click on the relays and swing to 20W pep with your variable power knob on the radio as low as it will go. turn on the amp, turn the radio output as low as it can go. amp off, turn up the radio.

    from what I've read, the variable pot burns out.
     
  7. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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    IMHO get the 500, with that radio you do not need the driver in the 667, your radio will work fine with the 500.
    You have enough radio to get the Max power out of the 4, 2879`s with out feeding extra current to the drivers.
    The Dial-a-watt uses a 2 watt variable, pressing the green dial-a-watt button also inserts a 75 ohm 4 watt metal oxide resistor "pad" for protecting the variable.
    More often than not they get dirty, it is a small carbon track inside and they just do not hold up well twisting them back and forth, if you are buying new, skip it and get the 4 button 500 and use the radio to control the drive power.
    If you are buying used and it is a V model, just run the amp with the red button in and again control the drive with the radio.
    For SSB just use the Yellow delay button.


    73
    Jeff
     
  8. n0zna

    n0zna Digital master

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    the 257hp is a 75 wtt radio and to much for the tx667 and tx500...you need a amp that will take 100 wtt drive like tx1200 or tx 1600...the 257hp is way to much for the smaller tx star amps,even if you turn it down it will still peak to much,73 de JW
     
  9. Mudfoot

    Mudfoot Sr. Member

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    No he doesn't.
     
  10. 9C1Driver

    9C1Driver Sr. Member

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    Holy crap, I see I am way late on this but I still have to say WOW. A 257 HP would blow the holy he!! out of a 667. Get the TS500V and your good to go.
     
  11. RADIOOMAN

    RADIOOMAN Active Member

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    I would recommend a straight 4 pill or straight 8 pill.
    No driver stage needed.
     
  12. Turbo T

    Turbo T Certified CB Rambo

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    Thanks, guess I'll take my eyes off the 667V and keep the hunt out for a 4 pill then.

    Are there any other amps besides Texas Star and maybe the TNT/Midnight Special line to look for? Going to be using the 257 on both AM and SSB.
     
  13. ExitThirteen

    ExitThirteen Grumpy and Cranky

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    You can use any straight 4 pill as long as it's biased for SSB use. If you're wanting something already biased out of the box, the TS-500 would be your best bet. If you don't mind sending it to someone to have the biasing installed, you can even go with the Class C straight 4 pills, like Davemade, X-Force, etc.

    The biggest key is to make sure it's AB biased for clean SSB signals.

    If you get a TS-500, make sure to get the 4 button version and not the variable, as high amounts of PEP wattage will burn out the variable pot if you run the variable anywhere other than wide open.


    Good luck!


    ~Cheers~
     
  14. Turbo T

    Turbo T Certified CB Rambo

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    How about this one for my 257HP? I read this is a 4 pill amp with 2879's in it....

    [​IMG]
     
  15. ExitThirteen

    ExitThirteen Grumpy and Cranky

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    If you detune the Magnum a lil bit, and get a tech to properly bias the transistors in that amp, that'd work fine. Don't see why it wouldn't work.

    (edit) You might not have to detune the Magnum... it depends on how the input transformers are wound on that amp... I don't know specs of the Midnight Specials offhand. They might be setup to run a 100W driver into them and be ok.


    ~Cheers~
     

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