Loading ...
Sorry, an error occurred while loading the content.

OT2 Audio Out Questions (Decoupling and Deviation)

Expand Messages
  • Edward
    Question 1: The OT2 has a 0.1uF decoupling capacitor on the Audio Out line. Is that correct? Question 2: In addition to the decoupling capacitor there is a
    Message 1 of 4 , Jan 6, 2012
    • 0 Attachment
      Question 1: The OT2 has a 0.1uF decoupling capacitor on the "Audio Out" line. Is that correct?

      Question 2: In addition to the decoupling capacitor there is a jumper "HI" that allows you to select use of either a A.) 100k resistor or B.) 100k resistor in parallel with a 30k (~23K). If I understand the circuit correctly the resistor(s) are used to control the voltage of the signal being sent to the transmitter (which in turns will control the deviation of the output signal). Is that correct?
    • James Ewen
      ... Yup. ... Nope... the HT jumper changes the loading on the line... Some HTs look for a load on the audio line when PTT is asserted, some HTs need a bit more
      Message 2 of 4 , Jan 6, 2012
      • 0 Attachment
        On Fri, Jan 6, 2012 at 12:01 PM, Edward <egiandomenico@...> wrote:

        > Question 1: The OT2 has a 0.1uF decoupling capacitor on the "Audio Out" line. Is that correct?

        Yup.

        > Question 2: In addition to the decoupling capacitor there is a jumper "HI" that allows
        > you to select use of either a A.) 100k resistor or B.) 100k resistor in parallel with a 30k
        > (~23K). If I understand the circuit correctly the resistor(s) are used to control the voltage
        > of the signal being sent to the transmitter (which in turns will control the deviation
        > of the output signal). Is that correct?

        Nope... the HT jumper changes the loading on the line... Some HTs look
        for a load on the audio line when PTT is asserted, some HTs need a bit
        more load than others... The audio (and it's deviation) are an AC
        signal superimposed on the DC on the circuit. The AC passes through
        the decoupling capacitor while the DC is being blocked. Deviation of
        the audio signal is controlled elsewhere, which in the OT2 is in the
        software.

        --
        James
        VE6SRV
      • Rob
        ... Yes, the *HI* jumper controls the TX audio level sent to the transmitter. It gives you finer resolution when using the TX level set in firmware (eg as set
        Message 3 of 4 , Jan 6, 2012
        • 0 Attachment
          On 07/01/12 04:08, James Ewen wrote:  

          On Fri, Jan 6, 2012 at 12:01 PM, Edward <egiandomenico@...> wrote:

          > Question 2: In addition to the decoupling capacitor there is a jumper "HI" that allows
          > you to select use of either a A.) 100k resistor or B.) 100k resistor in parallel with a 30k
          > (~23K). If I understand the circuit correctly the resistor(s) are used to control the voltage
          > of the signal being sent to the transmitter (which in turns will control the deviation
          > of the output signal). Is that correct?

          Nope... the HT jumper changes the loading on the line... Some HTs look


          Yes, the HI jumper controls the TX audio level sent to the transmitter. It gives you finer resolution when using the TX level set in firmware (eg as set by the otwincfg GUI or using the TXLEVEL command)

          The HT jumper is another thing :-)
          -- 
          Rob, VK6UFO, VK6RN
        • James Ewen
          ... Reading too fast, in between other tasks... shame, shame! Maybe I can use the excuse that I was reading so fast that the LCD display smeared the top of the
          Message 4 of 4 , Jan 6, 2012
          • 0 Attachment
            On Fri, Jan 6, 2012 at 4:47 PM, Rob <vk6ufo@...> wrote:

            > > Question 2: In addition to the decoupling capacitor there is a jumper "HI" that allows
            >
            > Yes, the HI jumper controls the TX audio level sent to the transmitter.
            >
            > The HT jumper is another thing :-)

            Reading too fast, in between other tasks... shame, shame!

            Maybe I can use the excuse that I was reading so fast that the LCD
            display smeared the top of the "I" as I read it!

            --
            James
            VE6SRV
          Your message has been successfully submitted and would be delivered to recipients shortly.