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Re: Sound card question

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On 10/02/2015 11:27 AM, Danny wrote:
>> I believe that the output of the headphone jack is not impedance matched--I expect it's just
>> a voltage source. Wat's more, unless you are plugging the same low-impedance devices into
>> both Y outputs, _and_ the source is impedance matched, you would not split the power
>> equally. I don't know what you want to do with the second output, but it's more
>> than likely a relatively high impedance, so it would not load the circuit at all.
>> I could be wrong, but it seems logical to me.
>>
>> --doug
>
> O.k ... let me explain why I asked the question for the sake of satisfying any
> curiosity:
>
> I have EchoLink (Ham Radio VOIP) connected to Jessie like this:
>
> VHF Transceiver (with two interface cables going to the MIC and LINE-OUT jacks
> on the back of an internal sound card. Incoming audio (radio frequency)
> goes through the antenna ... through the transciever ... to the sound
> card (via the MIC interface cable) ... it gets processed by the sound card and
> stuff happens on VOIP ... Because the VHF transceiver is effectively turned into a
> repeater NO transmit or recieve audio can be heard on the transciever itself
> (as it should be).
>
> In order to hear comms coming in or out of the transciever (via an antenna) one
> has to connect to the transciever with ANOTHER transciever in order to hear
> people talk (if you are tuned to the same frequency off course)
>
> Now ... my second transciever is fitted inside my car ... in order for me to
> hear all comms on the frequency I need to go to my car and turn that transciever
> on every now and then which becomes a pain in the donkey ... ;) ...
>
> In order for me NOT to make a trip to the car every 10 minutes I though of
> splitting the LINE-OUT and add a normal set of desktop speakers.
>
> So ... I was just wondering if I will have any losses (in whatever form) when I
> "split" the signal ... keep in mind that the audio signals processed by the sound
> card should be strong and reliable ...
>
> Thank You
>
> Danny
>
>
You didn't mention that you want to add _speakers_. You might need a small amplifier
after the Y-adapter, since the speakers will be low impedance--4- or 8 ohms.
Visit  ramseykits.com  and find some small audio amplifiers in kit or assembled
form. They are probably overkill for your purpose, but cheap enough. A 14W stereo
kit, CK154, will run on 12 to 16 VDC at 1A. $26 for a kit, or $34 assembled. You
provide an enclosure and a wall-wart to drive it. (The "14W" rating is for 7W per
channel, and I would expect that it's a peak rating, since 16V at 1A is 16 Watts
_input_ power! I would guess that rms power is more like 2 or 3 Watts per channel.)

I just noticed a smaller one in ramsey: CK122 $20 for the kit, $26 assembled.
0.5W per channel into 4 ohms. Runs on 6VDC. Probably enough for your purposes.

There are other small amplifier sources--check on Google.

--doug  

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Thread

Sound card question Danny <mynixmail@gmail.com> - 2015-09-30 16:00 +0200
  Re: Sound card question rlharris@oplink.net - 2015-09-30 16:40 +0200
    Re: Sound card question Danny <mynixmail@gmail.com> - 2015-10-01 15:50 +0200
  Re: Sound card question Doug <dmcgarrett@optonline.net> - 2015-09-30 19:50 +0200
    Re: Sound card question Seeker <seeker5528@comcast.net> - 2015-10-01 08:20 +0200
      Re: Sound card question Rob van der Putten <rob@sput.nl> - 2015-10-01 12:10 +0200
        Re: Sound card question Danny <mynixmail@gmail.com> - 2015-10-01 16:00 +0200
          Re: Sound card question Rob van der Putten <rob@sput.nl> - 2015-10-01 18:00 +0200
      Re: Sound card question Danny <mynixmail@gmail.com> - 2015-10-01 16:00 +0200
    Re: Sound card question Danny <mynixmail@gmail.com> - 2015-10-01 16:00 +0200
      Re: Sound card question rlharris@oplink.net - 2015-10-01 17:30 +0200
      Re: Sound card question Doug <dmcgarrett@optonline.net> - 2015-10-01 23:00 +0200
        Re: Sound card question rlharris@oplink.net - 2015-10-02 00:20 +0200
        Re: Sound card question rlharris@oplink.net - 2015-10-02 01:00 +0200
        Re: Sound card question Danny <mynixmail@gmail.com> - 2015-10-02 17:30 +0200
          Re: Sound card question Doug <dmcgarrett@optonline.net> - 2015-10-02 19:20 +0200
            Re: Sound card question rlharris@oplink.net - 2015-10-02 20:40 +0200
              Re: Sound card question Doug <dmcgarrett@optonline.net> - 2015-10-03 00:40 +0200
                Re: Sound card question rlharris@oplink.net - 2015-10-03 04:20 +0200
                Re: Sound card question Doug <dmcgarrett@optonline.net> - 2015-10-03 06:30 +0200
          RE: Sound card question "Larry Owens" <owens@netptc.net> - 2015-10-02 19:20 +0200
          Re: Sound card question David Wright <deblis@lionunicorn.co.uk> - 2015-10-02 19:30 +0200
          Re: Sound card question Stuart Longland <stuartl@longlandclan.id.au> - 2015-10-04 01:20 +0200
            Re: Sound card question rlharris@oplink.net - 2015-10-04 02:30 +0200
              Re: Sound card question Stuart Longland <stuartl@longlandclan.id.au> - 2015-10-05 23:00 +0200

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