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Cobra 19 ouch

Discussion in 'CB Radio Modifications' started by Bandit1, May 9, 2019.

  1. Bandit1

    Bandit1 Active Member

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    Ya ik I got a new Cobra 19 ultra 3 from a guy.i took it apart went to radio mods other sites.turned up the mod limiter

    Ik this radio has a inductor in the back.has anyone put a swing mod on these.
    I hearx these were the same as a DxIV



    I'd like to add a RF gain to it but the swing mod first
    Help
     

    Attached Files:


  2. loosecannon

    loosecannon Sr. Member

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    i certainly don't mean any disrespect, but if you don't have the knowledge and experience to be able to figure out the 'swing mod' on a radio like this yourself, you might reconsider opening up a CB shop and taking peoples' money to work on their radios.

    you may find different opinions on that depending on where you ask, but around here, when we see phrases like "turned up the mod limiter", and "swing mod" come from a supposed CB technician, we tend to tell people to steer clear of them.

    again, that's just around here and who knows, maybe everyone in your area loves your work.

    working out a 'swing mod' on a transformer modulated radio like this is apprentice level CB tech work, and if you know how and why they 'work', then applying that knowledge to other similar radios should be very simple.

    if i am off base here then i apologize.
    LC
     
    Bow, NZ8N, Robb and 2 others like this.
  3. nomadradio

    nomadradio Analog Retentive

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    Ghostrider, you have discovered the "black hole" of CB radio mods and upgrades. The lower the sale price of the radio, the more work is needed to turn up any technical info at all.

    Don't let anyone give you a hard time about modding a radio that's, er, "cheap". The fewer knobs it has, the more potential for upgrading it, right?

    But here's where the problem arises. Most of the mods out there are worked out by someone who does this stuff for hire. The more-expensive radios get all the attention, because those are the radios a tech's customers want to spend money to modify and upgrade.

    And this is where all those mods come from. A tech whose customers asked him to work out and install the mods on their radios. If he's feeling generous, it gets written up and posted on the web.

    Just one problem. The low-end radios are not the models that get these requests made. And the techs seldom work them out just for the amusement factor.

    Would be very cool if someone teased out the details, wrote up the step-by-step and posted pictures to go with it.

    But it will have to be someone else. Customers don't bring us many of these. More often than not the owner will simply trash it when it breaks.

    My starting point for most mods is the radio's schematic diagram. That info may be out there, but it's not in my library. Simply tracking down a schematic for the lowest-price radios can become a whole project by itself.

    But this is your biggest barrier for now, a wide information gap. Yes, it can be done, as soon as someone works out the nitty-gritties and chooses to share them on the web.

    73
     
  4. nomadradio

    nomadradio Analog Retentive

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    Quick update. Cobra has the tech info for the radio posted here:

    http://download.cobra.com/CB/Models/19DX4/

    Two versions, both of them are listed.

    Bad news is the radio is full of surface-mount parts on the solder side of the circuit board.

    Good news is that the component that gets removed, to connect the TIP120 carrier control transistor in its place is RT12, and it's not a surface mount part. It's a half-Watt 10-ohm resistor mounted on the component side.

    Just where you would locate the carrier-control pot is another whole question.

    73
     
  5. 711

    711 Well-Known Member

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    That link made it too easy to mod. I had to chase the foil runs down on the 880 and newer surface mount Uniden radios.
     
    loosecannon likes this.
  6. 9C1Driver

    9C1Driver Sr. Member

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    I'm already confused. You said,"turned up the mod limiter"? I think what you did was turned up the modulation VR pot. Or are you saying you clipped the limiter? Two very different things. Adding RF gain on such a small low featured radio would be a waste of time and money if it can even be done. Just do a proper alignment to the receive section and be done.
     
    Bow likes this.

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