Portable external speaker for KX3?

Discussion in 'QRP Corner' started by KD8ZM, May 19, 2018.

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  1. KC8VWM

    KC8VWM Ham Member QRZ Page

    How "portable" is portable?

    Rather than carry a bunch of stuff along separately, i'm fully self contained "go box portable" instead.

    So yes... accessories and batteries are included. :)

    pelican case.jpg

    I use a Motorola amplified speaker. Motorola is about as rugged as it gets for outdoor use.
    I tried out many other speakers before including different computer and portable DVD player speakers and I keep going back to this one...


    It's entirely engineered to sound fantastic for radio communications. It has a rather large size speaker inside when compared to most other external speakers. In terms of desiring others to be able to hear everything, this speaker has it's own built in 13 watt amplifier circuit that I can assure you is loud enough to wake up the dead. :D


    Selectable phones / external speaker switch idea.

    Last edited: May 29, 2018
    N4XRD and KD8ZM like this.
  2. KE5MC

    KE5MC Premium Subscriber QRZ Page

    Speaking of expensive, my buddy came back from Dayton with the Alex mic. Very nice! He is critical of what he hears and how he sounds on the air. He is a happy camper.

  3. KD8ZM

    KD8ZM Ham Member QRZ Page

    How does this relate to my question about the KX3? Will the KX3 drive that Motorola speaker, or will it need something to boost it? Thx.
  4. KC8VWM

    KC8VWM Ham Member QRZ Page

    It relates to your KX3 because you are looking for someone to recommend a good external speaker for the KX3.

    It's just like any other external speaker except it has a built in amplifier. I'm suspecting the built in amplifier circuitry will change the audio quality heard from the KX3.

    My FT-817 and even an HT's will drive it, so there's no reason at all why a KX3 won't.
    Last edited: May 30, 2018
    KD8ZM likes this.
  5. KD8ZM

    KD8ZM Ham Member QRZ Page

    Ah, ok, now I see. What model number is that speaker?
  6. KC8VWM

    KC8VWM Ham Member QRZ Page

    It's a Motorola NSN6054A - They are cheap to get on eBay and they are found all over the place.

    This is the user manual instructions with parts list / schematic etc..


    You can easily rewire these to use as a general purpose external speaker for ANY rig.

    This is what it looks like inside:


    The color coded wires are easy to figure out.

    7 wires are present on the original cable and hook up as follows:

    Black --- 12VDC -
    Brown -- 12VDC -

    Orange --12VDC+
    Green -- 12VDC+
    Red ----- 12VDC+

    White --- Audio IN
    Blue ----- Audio IN


    #1 Connect all the positive (+) wires together. (orange, green,red)
    #2 Connect all the negative (-) wires together. (black, brown)

    #3 Next, hook up to a 12v DC source to power the speaker from the (+) and (- ) power leads.

    (Side note : Optional , not required, but your choice... It's entirely possible to power the amplified speaker through the negative (-) lead through the audio cable ground which connects to the radio chassis - So whenever you unplug the speaker, it disconnects the DC power from the speaker! ) Alternatively, a simple switch may be installed on the DC line to turn off the speaker when not in use.

    #4 The audio IN wires are not polarized (they float) It doesn't matter whatsoever which way they are connected, or which wire is ground or hot. Hook up an appropriate audio cable to these two wires ( or solder directly to the amplifier board itself) Install a plug to fit your external speaker jack on your transceiver.


    This external amplified speaker is an upgrade for any transceiver !! The speaker draws very little current from the battery to operate the internal amplifier. I measured something like 30mA, so it's easy on your portable battery pack.

    These speakers are LOUD !! So it takes very little volume on the rig to drive the amplifier to a comfortable listening level. The audio fidelity and quality is amazing. Hears weak signals way down in the mud and makes weak signal intelligibility clear as a bell.

    Who needs DSP and other audio processing toys to hear things when you have one of these external speakers specifically optimized and engineered by Motorola just for 2 way radio communications?

    Enjoy the speaker upgrade.
    Last edited: May 30, 2018
    KD8ZM likes this.
  7. KE5MC

    KE5MC Premium Subscriber QRZ Page

    My bad! It a self powered speaker-mic. Plug and play ready for KX3.
  8. KD8ZM

    KD8ZM Ham Member QRZ Page

    Wow - you da man! Those are some good instructions, there. TU
    KC8VWM likes this.
  9. KD8ZM

    KD8ZM Ham Member QRZ Page

    Snagged one off of eBay - thanks for the tip!
    KC8VWM likes this.
  10. KC8VWM

    KC8VWM Ham Member QRZ Page

    Yup, you won't regret it. :)

    Best external speaker I ever owned by a long shot.
    Last edited: May 30, 2018
    KD8ZM likes this.

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