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? Max. Safe Dead Key Out On Texas Star 500 ?

Discussion in 'CB and Export Equipment and Accessories' started by Wire Weasel, Jun 26, 2018.

  1. Wire Weasel

    Wire Weasel Senior Moment

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    Hi guys, Texas Star 500V, 4 x 2879's. What is the maximum safe short term AM dead key out for these? It should do 100 watts all day long with proper fan cooling of course. But how high can you go without risking damage? Thanks !!


     

  2. Ranch55

    Ranch55 Well-Known Member

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    I have several Texas Star 500 amplifiers. All have Toshiba 2SC2879 transistors.
    With that said, on any Texas Star 500 with any brand transistor, I recommend a maximum transceiver dead key on AM, with mic gain turned off, an input of 4 watts from the radio......into the amplifier.
     
  3. Onelasttime

    Onelasttime Well-Known Member

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    I was thinking like you that he meant input watts from the radio going into the amp. After reading his post though I think he means what is a safe level of output that the TS-500 can sustain as in safe continuous duty cycle.

    Illegal CB amps are not really designed with a continuous duty cycle of sorts. It is not just the rf transistors you need to worry about. Builders do not use enough heat sink or pressurized air to allow for something like that as a norm.

    On top of that the type of modulation the radio has and the type of final it has have a huge impact on carrier vs modulated signal.

    If you thinking you can set the chicken choker and just walk away and come back 3 days later and all is good your not looking at a design can do that. Their are amps that can do not but none of them are built with CB'er's in mind.

    Trying to do this by carrier level is not the way to do this. What you need is to set a thermal limit that is unacceptable for long life. You need to have a thermal protection fault that can and will turn the unit off if that temp is reached. In this way it would not matter what you have the dead key set for if the temp goes to hi it trips the breaker and turns amp off.

    I live in a cold winter state so in the winter I could run at a power level that if ran for any time in the deep south would kill a device but it is safe for me due to low ambient temps.

    So rethink the question if you want to keep the parts happy and enjoy long life.
     
    Handy Andy likes this.
  4. nomadradio

    nomadradio Analog Retentive

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    Sweet spot is around 100 Watts carrier output. More than 150 will compromise the modulation, as a rule.

    73
     

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