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Audio hum

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  • Gary Peterson
    Well got the kit finished and tested - it both recieves and brings up the red transmit light with the test program, but..... there is a hum when the tnc is
    Message 1 of 10 , Aug 11, 2009
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      Well got the kit finished and tested - it both recieves and brings up the "red" transmit light with the test program, but..... there is a hum
      when the tnc is connected to the radio and I am transmitting voice communication. Suggestions?

      Next - has anyone found a simple tnc program wich will operate with the
      64 bit Vista program?

      Thanks in advance - Gary G. Peterson (WB6MAA)
    • Brian Wingfield
      Gary, Two -- if not more -- possibilities: 1. If I m not mistaken, the TNC-X always has a tone on the audio out line even if the PTT is not asserted. The tone
      Message 2 of 10 , Aug 12, 2009
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        Gary,

        Two -- if not more -- possibilities:

        1. If I'm not mistaken, the TNC-X always has a tone on the audio out
        line even if the PTT is not asserted. The tone is unmodulated when
        data is not being transmitted, but it is there. So, if your radio
        doesn't automatically mute the packet tx input when the microphone PTT
        is pressed, that is probably what you hear.

        2. Now, if your radio is supposed to mute the packet tx audio when the
        *microphone* PTT is pressed, then you may have a ground loop problem.
        One possible solution is to use an optoisolater on the PTT line and
        audio isolation transformers between the TNC-X and the radio (like a
        soundcard interface). Before you go to that much effort, try to make
        sure it is a ground loop problem. Does powering the TNC-X from a
        battery help? Do you still hear it if the TNC-X is connected to the
        radio, but not to the computer?

        -Brian

        On Tue, Aug 11, 2009 at 9:32 PM, Gary Peterson<garygpete@...> wrote:
        >
        >
        > Well got the kit finished and tested - it both recieves and brings up the
        > "red" transmit light with the test program, but..... there is a hum
        > when the tnc is connected to the radio and I am transmitting voice
        > communication. Suggestions?
        >
        > Next - has anyone found a simple tnc program wich will operate with the
        > 64 bit Vista program?
        >
        > Thanks in advance - Gary G. Peterson (WB6MAA)
        >
        >
      • Gary G. Peterson
        Hi Brian, The plot thickens - yes the audio hum is still present when the tnc is powered using the usb connection. But this morning it wants to constantly key
        Message 3 of 10 , Aug 12, 2009
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          Hi Brian,

           

          The plot thickens – yes the audio hum is still present when the tnc is powered using the usb

          connection.  But this morning it wants to constantly key up the transmitter and does not have to

          be powered up to cause this – so I will check the cable for shorting, but when the cables stereo

          plug is removed from the tnc, transmission keying stops, so I doubt it is a short within the cable.

          The tnc accesses the alnico 135 through a dedicated tnc port on the rear of the radio.  This port

          Is working fine with PK-3 system on the same computer.

           

          The tnc was purchased to go in my  “go box” for ACS and I wanted to simplify the needs for

          a packet system. I have not tried a battery for power, because I understood that the USB port

          could not be used with a external power source.

           

          I am still looking for a simple packet driver system to use with windows vista 64 bit and/or windows

          XP.

           

          Suggestins?

           

          From: tnc-x@yahoogroups.com [mailto:tnc-x@yahoogroups.com] On Behalf Of Brian Wingfield
          Sent: Wednesday, August 12, 2009 7:14 AM
          To: tnc-x@yahoogroups.com
          Subject: Re: [tnc-x] Audio hum

           

           

          Gary,

          Two -- if not more -- possibilities:

          1. If I'm not mistaken, the TNC-X always has a tone on the audio out
          line even if the PTT is not asserted. The tone is unmodulated when
          data is not being transmitted, but it is there. So, if your radio
          doesn't automatically mute the packet tx input when the microphone PTT
          is pressed, that is probably what you hear.

          2. Now, if your radio is supposed to mute the packet tx audio when the
          *microphone* PTT is pressed, then you may have a ground loop problem.
          One possible solution is to use an optoisolater on the PTT line and
          audio isolation transformers between the TNC-X and the radio (like a
          soundcard interface). Before you go to that much effort, try to make
          sure it is a ground loop problem. Does powering the TNC-X from a
          battery help? Do you still hear it if the TNC-X is connected to the
          radio, but not to the computer?

          -Brian

          On Tue, Aug 11, 2009 at 9:32 PM, Gary Peterson<garygpete@...> wrote:

          >
          >
          > Well got the kit finished and tested - it both recieves and brings up the
          > "red" transmit light with the test program, but..... there is a
          hum
          > when the tnc is connected to the radio and I am transmitting voice
          > communication. Suggestions?
          >
          > Next - has anyone found a simple tnc program wich will operate with the
          > 64 bit Vista program?
          >
          > Thanks in advance - Gary G. Peterson (WB6MAA)
          >
          >

        • kz6oscar
          Gary, I ve had a TNC-X for over a year and find your hum problem interesting. It sounds like a cabling problem with a ground either missing or not connected
          Message 4 of 10 , Aug 12, 2009
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            Gary,

            I've had a TNC-X for over a year and find your "hum" problem interesting. It sounds like a cabling problem with a ground either missing or not connected correctly. Strange as it might seem, you might try swapping your USB cable with another one. That was a problem for me that took a long time to find. One does not expect a brand new cable to be bad.

            Regarding an external battery, there is a jumper on the motherboard to select 5V from the USB port or 12V from the power connector. If you change that jumper, you can use USB with external power.

            As for software, I am using the AGW software from SV2AGW.COM on Windows XP. This set includes a driver for TNCs (set it as a TAPR TNC2 for the TNC-X), a terminal program, a monitor program, an APRS tracker program, and a digipeater program.

            Logan, KZ6O


            --- In tnc-x@yahoogroups.com, "Gary G. Peterson" <garygpete@...> wrote:
            >
            > Hi Brian,
            >
            >
            >
            > The plot thickens - yes the audio hum is still present when the tnc is
            > powered using the usb
            >
            > connection. But this morning it wants to constantly key up the transmitter
            > and does not have to
            >
            > be powered up to cause this - so I will check the cable for shorting, but
            > when the cables stereo
            >
            > plug is removed from the tnc, transmission keying stops, so I doubt it is a
            > short within the cable.
            >
            > The tnc accesses the alnico 135 through a dedicated tnc port on the rear of
            > the radio. This port
            >
            > Is working fine with PK-3 system on the same computer.
            >
            >
            >
            > The tnc was purchased to go in my "go box" for ACS and I wanted to simplify
            > the needs for
            >
            > a packet system. I have not tried a battery for power, because I understood
            > that the USB port
            >
            > could not be used with a external power source.
            >
            >
            >
            > I am still looking for a simple packet driver system to use with windows
            > vista 64 bit and/or windows
            >
            > XP.
            >
            >
            >
            > Suggestins?
            >
            >
            >
            > From: tnc-x@yahoogroups.com [mailto:tnc-x@yahoogroups.com] On Behalf Of
            > Brian Wingfield
            > Sent: Wednesday, August 12, 2009 7:14 AM
            > To: tnc-x@yahoogroups.com
            > Subject: Re: [tnc-x] Audio hum
            >
            >
            >
            >
            >
            > Gary,
            >
            > Two -- if not more -- possibilities:
            >
            > 1. If I'm not mistaken, the TNC-X always has a tone on the audio out
            > line even if the PTT is not asserted. The tone is unmodulated when
            > data is not being transmitted, but it is there. So, if your radio
            > doesn't automatically mute the packet tx input when the microphone PTT
            > is pressed, that is probably what you hear.
            >
            > 2. Now, if your radio is supposed to mute the packet tx audio when the
            > *microphone* PTT is pressed, then you may have a ground loop problem.
            > One possible solution is to use an optoisolater on the PTT line and
            > audio isolation transformers between the TNC-X and the radio (like a
            > soundcard interface). Before you go to that much effort, try to make
            > sure it is a ground loop problem. Does powering the TNC-X from a
            > battery help? Do you still hear it if the TNC-X is connected to the
            > radio, but not to the computer?
            >
            > -Brian
            >
            > On Tue, Aug 11, 2009 at 9:32 PM, Gary Peterson<garygpete@...
            > <mailto:garygpete%40roadrunner.com> > wrote:
            > >
            > >
            > > Well got the kit finished and tested - it both recieves and brings up the
            > > "red" transmit light with the test program, but..... there is a hum
            > > when the tnc is connected to the radio and I am transmitting voice
            > > communication. Suggestions?
            > >
            > > Next - has anyone found a simple tnc program wich will operate with the
            > > 64 bit Vista program?
            > >
            > > Thanks in advance - Gary G. Peterson (WB6MAA)
            > >
            > >
            >
          • Brian Wingfield
            Gary, 1. You didn t say you ruled out the 1st possibility. Would you describe the hum as around 60 Hz, or could it be the 1200 Hz or 2200 Hz mark/space tone?
            Message 5 of 10 , Aug 12, 2009
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              Gary,

              1. You didn't say you ruled out the 1st possibility. Would you
              describe the hum as around 60 Hz, or could it be the 1200 Hz or 2200
              Hz mark/space tone? If the PK-3 doesn't emit audio when not
              transmitting, you wouldn't have noticed this possibility with it.

              2. I was using my TNC-X with an Alinco DR-605T and had problems with
              the PTT hanging up (stuck on) after a packet tranmission. I added
              bypass capacitors between each lead of the PTT in the TNC-X transistor
              to reduce its sensitivity to RF. That worked. See the archives of
              this re-mailer list for more info.

              3. There is a jumper that determines whether the tnc uses USB power.
              You can remove it (or move it -- consult the schematic) if you want to
              try the battery. That way you could power up the TNC and radio with
              them completely disconnected from the PC to eliminate the PC as the
              source of the hum.

              4. My guess is that you are on to something with the cables. You
              could have an intermittent problem that goes away when you flex it. A
              re-check of pin-out information, and continuity and shorting checks
              would be wise. For example, you've probably heard the type of hum you
              get when a guitar to amplifier cable is bad or not completely plugged
              in.

              -Brian






              On Wed, Aug 12, 2009 at 11:17 AM, Gary G.
              Peterson<garygpete@...> wrote:
              >
              >
              > Hi Brian,
              >
              >
              >
              > The plot thickens – yes the audio hum is still present when the tnc is
              > powered using the usb
              >
              > connection.  But this morning it wants to constantly key up the transmitter
              > and does not have to
              >
              > be powered up to cause this – so I will check the cable for shorting, but
              > when the cables stereo
              >
              > plug is removed from the tnc, transmission keying stops, so I doubt it is a
              > short within the cable.
              >
              > The tnc accesses the alnico 135 through a dedicated tnc port on the rear of
              > the radio.  This port
              >
              > Is working fine with PK-3 system on the same computer.
              >
              >
              >
              > The tnc was purchased to go in my  “go box” for ACS and I wanted to simplify
              > the needs for
              >
              > a packet system. I have not tried a battery for power, because I understood
              > that the USB port
              >
              > could not be used with a external power source.
              >
              >
              >
              > I am still looking for a simple packet driver system to use with windows
              > vista 64 bit and/or windows
              >
              > XP.
              >
              >
              >
              > Suggestins?
              >
              >
              >
              > From: tnc-x@yahoogroups.com [mailto:tnc-x@yahoogroups.com] On Behalf Of
              > Brian Wingfield
              > Sent: Wednesday, August 12, 2009 7:14 AM
              > To: tnc-x@yahoogroups.com
              > Subject: Re: [tnc-x] Audio hum
              >
              >
              >
              >
              >
              > Gary,
              >
              > Two -- if not more -- possibilities:
              >
              > 1. If I'm not mistaken, the TNC-X always has a tone on the audio out
              > line even if the PTT is not asserted. The tone is unmodulated when
              > data is not being transmitted, but it is there. So, if your radio
              > doesn't automatically mute the packet tx input when the microphone PTT
              > is pressed, that is probably what you hear.
              >
              > 2. Now, if your radio is supposed to mute the packet tx audio when the
              > *microphone* PTT is pressed, then you may have a ground loop problem.
              > One possible solution is to use an optoisolater on the PTT line and
              > audio isolation transformers between the TNC-X and the radio (like a
              > soundcard interface). Before you go to that much effort, try to make
              > sure it is a ground loop problem. Does powering the TNC-X from a
              > battery help? Do you still hear it if the TNC-X is connected to the
              > radio, but not to the computer?
              >
              > -Brian
              >
              > On Tue, Aug 11, 2009 at 9:32 PM, Gary Peterson<garygpete@...>
              > wrote:
              >>
              >>
              >> Well got the kit finished and tested - it both recieves and brings up the
              >> "red" transmit light with the test program, but..... there is a hum
              >> when the tnc is connected to the radio and I am transmitting voice
              >> communication. Suggestions?
              >>
              >> Next - has anyone found a simple tnc program wich will operate with the
              >> 64 bit Vista program?
              >>
              >> Thanks in advance - Gary G. Peterson (WB6MAA)
              >>
              >>
              >
              >
            • Theodore A. Antanaitis
              [...snip...] Would you describe the hum as around 60 Hz, or could it be the 1200 Hz or 2200 Hz mark/space tone? [...snip...] Not quite correct, referring to:
              Message 6 of 10 , Aug 12, 2009
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                [...snip...]
                Would you describe the hum as around 60 Hz, or could it be the 1200 Hz or
                2200
                Hz mark/space tone?
                [...snip...]

                Not quite correct, referring to:

                http://fettechnologies.com/tncx.html

                "When the TNC-X is idle, the mode select pins to the modem chip are both
                logic 0. This puts the MX614P into a mode where it is transmitting a 487Hz
                tone."

                This lower tone frequency could easily be interpreted as 'hum'.

                I confirmed the presence of this tone frequency on my new TNC-X output just
                two days ago when I was setting up my deviation level.

                73
                Ted WA7ZZB
              • Gary Peterson
                ... Well I have used both the usb cable and a external 12v supply for the tnc. In both cases the tone is present. I also have made a 2nd set of interface
                Message 7 of 10 , Aug 12, 2009
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                  --- In tnc-x@yahoogroups.com, "Theodore A. Antanaitis" <WA7ZZB@...> wrote:
                  >
                  > [...snip...]
                  > Would you describe the hum as around 60 Hz, or could it be the 1200 Hz or
                  > 2200
                  > Hz mark/space tone?
                  > [...snip...]
                  >
                  > Not quite correct, referring to:
                  >
                  > http://fettechnologies.com/tncx.html
                  >
                  > "When the TNC-X is idle, the mode select pins to the modem chip are both
                  > logic 0. This puts the MX614P into a mode where it is transmitting a 487Hz
                  > tone."
                  >
                  > This lower tone frequency could easily be interpreted as 'hum'.
                  >
                  > I confirmed the presence of this tone frequency on my new TNC-X output just
                  > two days ago when I was setting up my deviation level.
                  >
                  > 73
                  > Ted WA7ZZB
                  >
                  Well I have used both the usb cable and a external 12v supply for the
                  tnc. In both cases the "tone" is present. I also have made a 2nd set
                  of interface cables for the radio side and discovered a short in the old set which occured in the cable itself.

                  Since the "tone" is still there I am going to operate on the idea that it supposed to be there.

                  The next step will be to download a program for the operation of the
                  computer/tnc. (I already have two programs used for this, but they are
                  written for specific TNC's - and do not function with the TNC-X)

                  Wish me luck.
                  Gary Peterson (WB6MAA)

                  P.S. - thanks you all for your ideas and help!!!
                • Howard Z.
                  Gary, you have encountered the fatal flaw with the TNC-X. You gotta move your antenna at least 20 feet away - moving it up is better than just away. If the
                  Message 8 of 10 , Aug 19, 2009
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                    Gary, you have encountered the fatal flaw with the TNC-X.

                    You gotta move your antenna at least 20 feet away - moving it up is better than just away.

                    If the radio's antenna is near the TNC-X - even if you are only XMTing 5 watts - the TNC-X will get stuck in XMT mode. I don't recall for sure if it is accompanied by a hum or not. The capacitor fix doesn't really fix it - what will then happen is after the TNC-X is exposed to RF you will never ever receive a packet until the TNC-X is powered off and back on. I suppose never hearing is better than always transmitting - but either way you have a TNC that will continue to malfunction until it is powered off and back on.

                    You get what you paid for.
                    If you want a good TNC that is immune to its own radio's RF, then spend a few hundred dollars.

                    Sorry you had to learn the hard way after investing time and money in the TNC-X. Maybe you should first have visited www.eham.net/reviews ?

                    I have a home-made copper-pipe j-pole antenna outside the house - 10 ft away and the bottom of the antenna 10 ft high - this has eliminated the problems for my TNC-X. If you can't put up an outdoor antenna where you live - then think about Ebaying the TNC-X to someone who can.

                    Howard


                    --- In tnc-x@yahoogroups.com, "Gary G. Peterson" <garygpete@...> wrote:
                    >
                    > Hi Brian,
                    >
                    >
                    >
                    > The plot thickens - yes the audio hum is still present when the tnc is
                    > powered using the usb
                    >
                    > connection. But this morning it wants to constantly key up the transmitter
                    > and does not have to
                    >
                    > be powered up to cause this - so I will check the cable for shorting, but
                    > when the cables stereo
                    >
                    > plug is removed from the tnc, transmission keying stops, so I doubt it is a
                    > short within the cable.
                    >
                    > The tnc accesses the alnico 135 through a dedicated tnc port on the rear of
                    > the radio. This port
                    >
                    > Is working fine with PK-3 system on the same computer.
                    >
                    >
                    >
                    > The tnc was purchased to go in my "go box" for ACS and I wanted to simplify
                    > the needs for
                    >
                    > a packet system. I have not tried a battery for power, because I understood
                    > that the USB port
                    >
                    > could not be used with a external power source.
                    >
                    >
                    >
                    > I am still looking for a simple packet driver system to use with windows
                    > vista 64 bit and/or windows
                    >
                    > XP.
                    >
                    >
                    >
                    > Suggestins?
                    >
                    >
                    >
                    > From: tnc-x@yahoogroups.com [mailto:tnc-x@yahoogroups.com] On Behalf Of
                    > Brian Wingfield
                    > Sent: Wednesday, August 12, 2009 7:14 AM
                    > To: tnc-x@yahoogroups.com
                    > Subject: Re: [tnc-x] Audio hum
                    >
                    >
                    >
                    >
                    >
                    > Gary,
                    >
                    > Two -- if not more -- possibilities:
                    >
                    > 1. If I'm not mistaken, the TNC-X always has a tone on the audio out
                    > line even if the PTT is not asserted. The tone is unmodulated when
                    > data is not being transmitted, but it is there. So, if your radio
                    > doesn't automatically mute the packet tx input when the microphone PTT
                    > is pressed, that is probably what you hear.
                    >
                    > 2. Now, if your radio is supposed to mute the packet tx audio when the
                    > *microphone* PTT is pressed, then you may have a ground loop problem.
                    > One possible solution is to use an optoisolater on the PTT line and
                    > audio isolation transformers between the TNC-X and the radio (like a
                    > soundcard interface). Before you go to that much effort, try to make
                    > sure it is a ground loop problem. Does powering the TNC-X from a
                    > battery help? Do you still hear it if the TNC-X is connected to the
                    > radio, but not to the computer?
                    >
                    > -Brian
                    >
                    > On Tue, Aug 11, 2009 at 9:32 PM, Gary Peterson<garygpete@...
                    > <mailto:garygpete%40roadrunner.com> > wrote:
                    > >
                    > >
                    > > Well got the kit finished and tested - it both recieves and brings up the
                    > > "red" transmit light with the test program, but..... there is a hum
                    > > when the tnc is connected to the radio and I am transmitting voice
                    > > communication. Suggestions?
                    > >
                    > > Next - has anyone found a simple tnc program wich will operate with the
                    > > 64 bit Vista program?
                    > >
                    > > Thanks in advance - Gary G. Peterson (WB6MAA)
                    > >
                    > >
                    >
                  • kz6oscar
                    Here is something to try...... Put 7 turns of the PTT wire thru a FT37-43 core (red) before you connect the wire to the motherboard. Cured the problem for me.
                    Message 9 of 10 , Aug 19, 2009
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                      Here is something to try......

                      Put 7 turns of the PTT wire thru a FT37-43 core (red) before you connect the wire to the motherboard. Cured the problem for me. I ran the TNC right next to a ground plane with 50 watts.

                      Logan, KZ6O

                      --- In tnc-x@yahoogroups.com, "Howard Z." <Howard_Z@...> wrote:
                      >
                      > Gary, you have encountered the fatal flaw with the TNC-X.
                      >
                      > You gotta move your antenna at least 20 feet away - moving it up is better than just away.
                      >
                      > If the radio's antenna is near the TNC-X - even if you are only XMTing 5 watts - the TNC-X will get stuck in XMT mode. I don't recall for sure if it is accompanied by a hum or not. The capacitor fix doesn't really fix it - what will then happen is after the TNC-X is exposed to RF you will never ever receive a packet until the TNC-X is powered off and back on. I suppose never hearing is better than always transmitting - but either way you have a TNC that will continue to malfunction until it is powered off and back on.
                      >
                      > You get what you paid for.
                      > If you want a good TNC that is immune to its own radio's RF, then spend a few hundred dollars.
                      >
                      > Sorry you had to learn the hard way after investing time and money in the TNC-X. Maybe you should first have visited www.eham.net/reviews ?
                      >
                      > I have a home-made copper-pipe j-pole antenna outside the house - 10 ft away and the bottom of the antenna 10 ft high - this has eliminated the problems for my TNC-X. If you can't put up an outdoor antenna where you live - then think about Ebaying the TNC-X to someone who can.
                      >
                      > Howard
                      >
                      >
                      > --- In tnc-x@yahoogroups.com, "Gary G. Peterson" <garygpete@> wrote:
                      > >
                      > > Hi Brian,
                      > >
                      > >
                      > >
                      > > The plot thickens - yes the audio hum is still present when the tnc is
                      > > powered using the usb
                      > >
                      > > connection. But this morning it wants to constantly key up the transmitter
                      > > and does not have to
                      > >
                      > > be powered up to cause this - so I will check the cable for shorting, but
                      > > when the cables stereo
                      > >
                      > > plug is removed from the tnc, transmission keying stops, so I doubt it is a
                      > > short within the cable.
                      > >
                      > > The tnc accesses the alnico 135 through a dedicated tnc port on the rear of
                      > > the radio. This port
                      > >
                      > > Is working fine with PK-3 system on the same computer.
                      > >
                      > >
                      > >
                      > > The tnc was purchased to go in my "go box" for ACS and I wanted to simplify
                      > > the needs for
                      > >
                      > > a packet system. I have not tried a battery for power, because I understood
                      > > that the USB port
                      > >
                      > > could not be used with a external power source.
                      > >
                      > >
                      > >
                      > > I am still looking for a simple packet driver system to use with windows
                      > > vista 64 bit and/or windows
                      > >
                      > > XP.
                      > >
                      > >
                      > >
                      > > Suggestins?
                      > >
                      > >
                      > >
                      > > From: tnc-x@yahoogroups.com [mailto:tnc-x@yahoogroups.com] On Behalf Of
                      > > Brian Wingfield
                      > > Sent: Wednesday, August 12, 2009 7:14 AM
                      > > To: tnc-x@yahoogroups.com
                      > > Subject: Re: [tnc-x] Audio hum
                      > >
                      > >
                      > >
                      > >
                      > >
                      > > Gary,
                      > >
                      > > Two -- if not more -- possibilities:
                      > >
                      > > 1. If I'm not mistaken, the TNC-X always has a tone on the audio out
                      > > line even if the PTT is not asserted. The tone is unmodulated when
                      > > data is not being transmitted, but it is there. So, if your radio
                      > > doesn't automatically mute the packet tx input when the microphone PTT
                      > > is pressed, that is probably what you hear.
                      > >
                      > > 2. Now, if your radio is supposed to mute the packet tx audio when the
                      > > *microphone* PTT is pressed, then you may have a ground loop problem.
                      > > One possible solution is to use an optoisolater on the PTT line and
                      > > audio isolation transformers between the TNC-X and the radio (like a
                      > > soundcard interface). Before you go to that much effort, try to make
                      > > sure it is a ground loop problem. Does powering the TNC-X from a
                      > > battery help? Do you still hear it if the TNC-X is connected to the
                      > > radio, but not to the computer?
                      > >
                      > > -Brian
                      > >
                      > > On Tue, Aug 11, 2009 at 9:32 PM, Gary Peterson<garygpete@
                      > > <mailto:garygpete%40roadrunner.com> > wrote:
                      > > >
                      > > >
                      > > > Well got the kit finished and tested - it both recieves and brings up the
                      > > > "red" transmit light with the test program, but..... there is a hum
                      > > > when the tnc is connected to the radio and I am transmitting voice
                      > > > communication. Suggestions?
                      > > >
                      > > > Next - has anyone found a simple tnc program wich will operate with the
                      > > > 64 bit Vista program?
                      > > >
                      > > > Thanks in advance - Gary G. Peterson (WB6MAA)
                      > > >
                      > > >
                      > >
                      >
                    • cclcrac
                      I have 3 TNC-x s. Bypassing the PTT transistor with a small cap works for me on all of them. As for packet driver software... I use these TNC s with the
                      Message 10 of 10 , Sep 1, 2009
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                        I have 3 TNC-x's. Bypassing the PTT transistor with a small cap works for me on all of them.
                        As for "packet driver" software... I use these TNC's with the AGWPE Pro software. Works great. Really nice thing about this software is that you can have multiple applications sharing the tnc without worrying about applications hoging the com/usb ports. I've not tried that software on Vista, but I know it works great on W2k and XP.
                        I use this for kbd-kbd packet, aprs, winlink, etc. I also have one of the digi daughter boards to use as a fill-in.. that works fine to.


                        --- In tnc-x@yahoogroups.com, "kz6oscar" <lrahnz@...> wrote:
                        >
                        > Here is something to try......
                        >
                        > Put 7 turns of the PTT wire thru a FT37-43 core (red) before you connect the wire to the motherboard. Cured the problem for me. I ran the TNC right next to a ground plane with 50 watts.
                        >
                        > Logan, KZ6O
                        >
                        > --- In tnc-x@yahoogroups.com, "Howard Z." <Howard_Z@> wrote:
                        > >
                        > > Gary, you have encountered the fatal flaw with the TNC-X.
                        > >
                        > > You gotta move your antenna at least 20 feet away - moving it up is better than just away.
                        > >
                        > > If the radio's antenna is near the TNC-X - even if you are only XMTing 5 watts - the TNC-X will get stuck in XMT mode. I don't recall for sure if it is accompanied by a hum or not. The capacitor fix doesn't really fix it - what will then happen is after the TNC-X is exposed to RF you will never ever receive a packet until the TNC-X is powered off and back on. I suppose never hearing is better than always transmitting - but either way you have a TNC that will continue to malfunction until it is powered off and back on.
                        > >
                        > > You get what you paid for.
                        > > If you want a good TNC that is immune to its own radio's RF, then spend a few hundred dollars.
                        > >
                        > > Sorry you had to learn the hard way after investing time and money in the TNC-X. Maybe you should first have visited www.eham.net/reviews ?
                        > >
                        > > I have a home-made copper-pipe j-pole antenna outside the house - 10 ft away and the bottom of the antenna 10 ft high - this has eliminated the problems for my TNC-X. If you can't put up an outdoor antenna where you live - then think about Ebaying the TNC-X to someone who can.
                        > >
                        > > Howard
                        > >
                        > >
                        > > --- In tnc-x@yahoogroups.com, "Gary G. Peterson" <garygpete@> wrote:
                        > > >
                        > > > Hi Brian,
                        > > >
                        > > >
                        > > >
                        > > > The plot thickens - yes the audio hum is still present when the tnc is
                        > > > powered using the usb
                        > > >
                        > > > connection. But this morning it wants to constantly key up the transmitter
                        > > > and does not have to
                        > > >
                        > > > be powered up to cause this - so I will check the cable for shorting, but
                        > > > when the cables stereo
                        > > >
                        > > > plug is removed from the tnc, transmission keying stops, so I doubt it is a
                        > > > short within the cable.
                        > > >
                        > > > The tnc accesses the alnico 135 through a dedicated tnc port on the rear of
                        > > > the radio. This port
                        > > >
                        > > > Is working fine with PK-3 system on the same computer.
                        > > >
                        > > >
                        > > >
                        > > > The tnc was purchased to go in my "go box" for ACS and I wanted to simplify
                        > > > the needs for
                        > > >
                        > > > a packet system. I have not tried a battery for power, because I understood
                        > > > that the USB port
                        > > >
                        > > > could not be used with a external power source.
                        > > >
                        > > >
                        > > >
                        > > > I am still looking for a simple packet driver system to use with windows
                        > > > vista 64 bit and/or windows
                        > > >
                        > > > XP.
                        > > >
                        > > >
                        > > >
                        > > > Suggestins?
                        > > >
                        > > >
                        > > >
                        > > > From: tnc-x@yahoogroups.com [mailto:tnc-x@yahoogroups.com] On Behalf Of
                        > > > Brian Wingfield
                        > > > Sent: Wednesday, August 12, 2009 7:14 AM
                        > > > To: tnc-x@yahoogroups.com
                        > > > Subject: Re: [tnc-x] Audio hum
                        > > >
                        > > >
                        > > >
                        > > >
                        > > >
                        > > > Gary,
                        > > >
                        > > > Two -- if not more -- possibilities:
                        > > >
                        > > > 1. If I'm not mistaken, the TNC-X always has a tone on the audio out
                        > > > line even if the PTT is not asserted. The tone is unmodulated when
                        > > > data is not being transmitted, but it is there. So, if your radio
                        > > > doesn't automatically mute the packet tx input when the microphone PTT
                        > > > is pressed, that is probably what you hear.
                        > > >
                        > > > 2. Now, if your radio is supposed to mute the packet tx audio when the
                        > > > *microphone* PTT is pressed, then you may have a ground loop problem.
                        > > > One possible solution is to use an optoisolater on the PTT line and
                        > > > audio isolation transformers between the TNC-X and the radio (like a
                        > > > soundcard interface). Before you go to that much effort, try to make
                        > > > sure it is a ground loop problem. Does powering the TNC-X from a
                        > > > battery help? Do you still hear it if the TNC-X is connected to the
                        > > > radio, but not to the computer?
                        > > >
                        > > > -Brian
                        > > >
                        > > > On Tue, Aug 11, 2009 at 9:32 PM, Gary Peterson<garygpete@
                        > > > <mailto:garygpete%40roadrunner.com> > wrote:
                        > > > >
                        > > > >
                        > > > > Well got the kit finished and tested - it both recieves and brings up the
                        > > > > "red" transmit light with the test program, but..... there is a hum
                        > > > > when the tnc is connected to the radio and I am transmitting voice
                        > > > > communication. Suggestions?
                        > > > >
                        > > > > Next - has anyone found a simple tnc program wich will operate with the
                        > > > > 64 bit Vista program?
                        > > > >
                        > > > > Thanks in advance - Gary G. Peterson (WB6MAA)
                        > > > >
                        > > > >
                        > > >
                        > >
                        >
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