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Tube amplifier

Discussion in 'CB Radio Gear SwapShop' started by fritzoreo, Dec 7, 2018.

  1. fritzoreo

    fritzoreo Supporting Member

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    Can anyone tell me who builds a good 11 meter tube amp besides wizard. Thanks


     

  2. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Ameritron Amplifier, made in the USA!
    Good equipment.
     
    w9cll, sp5it and Shadetree Mechanic like this.
  3. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Why by a crap 11m amp when amateur radio amps are MUCH cleaner and better made? Unless of course you want to run ridiculous power levels and splatter all over the band.
     
  4. jessejamesdallas

    jessejamesdallas Sr. Member

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    I can think of a couple of reasons...one being "Price"...

    You can run one of the old "CB" tube amps and get a clean signal out, without splattering 40-up and 40-down if you have the amp and radio properly tuned...

    With my Cobra 2000 I run either a "Kicker 500" (1x3 tube) or my Palomar 300A (2x4 tube), and have a very clean sounding signal both on AM and SSB...Don't bleed on anything in the house or my neighbors house's...and get complements daily on how good and clean the radio sounds...

    Tubes ar fairly expencive now days tho, but they last forever as long as you don't push the snot out of them...
     
    Shadetree Mechanic likes this.
  5. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Precisely why I said an amateur amp would be fine unless he wanted to run a splatterbox which is typically the kind of customers Whizard sees. Tube amps are much cleaner when run PROPERLY than SS amps are and I don't mean just in regards to harmonics but IMD as well.
     
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  6. wavrider

    wavrider W9WDX Amateur Radio Club Member

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    To answer the question posted???

    Wizard made amps are questionable to say the least, and I have heard rumors that he is now calling his products Eagle made but that is only rumor.

    Now what exactly type operations are you looking to do with your "tube" amp?
    AM or SSB, the different modes will require different type power supplies.

    SSB is usually a lighter type PS due to the duty cycle of the mode roughly 15 to 20% duty cycle.

    If you wanting to be a BIG HAMMER splatter box operator on AM then get ready to pay out the $$$ for the power supply required to operate a "tube" amp on AM mode.

    Many amateur amps on the market, local adds craigslist, etc etc that if operated with common sense will gives years of trouble free use and clean signals.

    Over drive them to get "MO WATTTS" and you will be visiting your repair tech on a regular basis.

    There are a few amp builders out there that do take the time and expense to make a good product, but you are going pay $$$ for that product.
     
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  7. Shockwave

    Shockwave Sr. Member

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    How clean a tube amp runs usually has more to do with who is operating it rather than who built it.
     
  8. RT431

    RT431 New Member

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    Precisely. A dirty signal I , a dirty signal out.
     
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  9. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    Shadetree Mechanic likes this.
  10. 543_Dallas

    543_Dallas Sr. Member

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    I've fallen out of the loop on who builds what these days because it all seems to be on Facebook. BM Technology used to be what I suggested but I don't even know of he's still building amps.

    Big sweep tube amps are a money pit. Not much plate dissipation for your dollar.
     
  11. Shockwave

    Shockwave Sr. Member

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    The biggest problem with sweep tube amps is I can't remember when the last time I've seen one for this band with a decent bias circuit. The designers couldn't resist the temptation to just ground the cathodes in transmit. With 900 volts on the plate when you ground the cathode without applying a negative bias voltage, the DC alone is enough to turn the sweep tubes red without any RF drive. Some diodes with an RF bypass cap work well when placed in series with the cathodes and relay contact that grounds them in TX.

    If you want to do a really good job and add precision control of the bias voltage, use a shunt regulator like the TL431 to drive a larger pass transistor. If you need a schematic of this, the basic bias circuit can be seen in use on "The Triode Board" kit sold by IFWTech. If you think there is a chance your tubes are gassy and may experience an internal arc, never use a transistor based regulator in series with the cathode. The silicon diode string is your best friend here because it's the only part I've found that can handle this fault.
     
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  12. Shockwave

    Shockwave Sr. Member

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    To best answer the original question, the buyer should gain some first hand knowledge on how to determine if the equipment is quality or not. If you're buying something "custom", don't purchase anything from anyone that won't share some photos of their previous work. If you show photos on this website, there are enough knowledgeable people here to help you spot things that will make a difference before making a mistake.

    You'll learn things like how to tell if the AC mains cord is properly RF bypassed so it does not radiate RFI to everyone on your distribution transformer. Do the meters have shielding, diode protection and bypass caps behind them? Has the input circuit been designed as a low pass filter with anything that looks like the right "Q"? Does the power supply and tank circuit look like it could handle the current that would be present to produce the advertised output? Can the tube match that supply without overheating and is it a reliable type that is still available? Is there any form of over current protection or even a glitch resistor? These are the questions inquiring minds would want answers to.
     
  13. 543_Dallas

    543_Dallas Sr. Member

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    If a person knows enough about amps to really pick one apart like that they should build it themselves or find a dead one to resurrect.
     
    Shadetree Mechanic likes this.
  14. fritzoreo

    fritzoreo Supporting Member

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    Thanks for your help guys
     
  15. ButtFuzz

    ButtFuzz Anti-BS Advocate ● N4REV ● Reverend Doctor

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    "You'll learn things like how to tell if the AC mains cord is properly RF bypassed so it does not radiate RFI to everyone on your distribution transformer."

    They call me ButtFuzz, and I'm 4 days away from my 3rd consecutive WATT award!

    Worked All Them Toasters!
     
    Shadetree Mechanic likes this.

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