[arm-allstar] DTMF tones not decoded properly

Doug Crompton wa3dsp at gmail.com
Sat Mar 30 01:34:26 EDT 2019


Brian,

 Not sure what to say. If you have taken the 4.7 K resistor to pin 21 out
and it still needs to be a max level with boost on there is something
different in that radio or possibly the DMK is not functioning properly
which would be unusual. Minus test equipment like a scope it would be hard
to diagnose. BTW there is no reason to disconnect the speaker. It is good
to leave it connected for testing. All you need to do is turn it down. The
volume control should have no effect on the rx level if you connected to
the high side of the pot.


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*

On Sat, Mar 30, 2019 at 12:28 AM "B Harvey via ARM-allstar" <
arm-allstar at hamvoip.org> wrote:

> Doug,
>
>
>    This is the link to the Hamvoip.org  tutorial for using an Baofeng UV 82
> as a node radio. ( https://hamvoip.org/hamradio/UV82_mod/ )According to
> it,
> there is a 4.7Kohm resistor in series with the lead to Pin 21. I confirmed
> this and measured the resistance to confirm before I removed it. (FYI,
> there's also one in series with the transmit line. I thought something
> seemed off as well. I would have expected plenty of gain especially with
> the setting at 999 and no resistor. Although I've disconnected the speaker,
> I have checked the volume with a lapel/mic and all seems normal. This was a
> working radio and I hadn't detected any problems prior to setting it up as
> a node radio. I did a resistance check of all of the DB25 pins to radio
> solder points. I'm within  a few percent of 4.7Kohms on the RX and TX lines
> and about 2 ohms on the ground. Since the PTT and COS are working, I didn't
> measure those. I suppose the tutorial could be wrong and I'm on the ground
> side of the volume pot but I'd expect no signal at all from there.
>
>
> Brian / KK6DOQ
>
> On Fri, Mar 29, 2019 at 6:14 PM "Doug Crompton via ARM-allstar" <
> arm-allstar at hamvoip.org> wrote:
>
> > Brian,
> >
> >  Since this is a homebrew project please tell me what resistors you have
> in
> > the RX path. Generally audio is taken from the high side of the volume
> pot
> > then fed to pin 21 of the DMK URI. I forget if that is what you are using
> > for a FOB? The 'B' boost item in simpleusb-tune-menu needs to be enabled.
> > Something is not right if you need to be at 999 and you are directly
> > connected from that point in the radio to the FOB. You should be able to
> > achieve a 5khz level on the item 2 bar graph with a setting of around
> > 500-700.
> >
> >
> > *73 Doug*
> >
> > *WA3DSP*
> >
> > *http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*
> >
> > On Fri, Mar 29, 2019 at 8:56 PM "B Harvey via ARM-allstar" <
> > arm-allstar at hamvoip.org> wrote:
> >
> > > Don,
> > >
> > >     I checked the codeplugs for the radios I've been using. All are set
> > to
> > > wideband so I don't think I have a problem there. In the simple USB
> tune
> > > menu I checked the levels and with the default settings, for RX, I was
> > > barely moving the "VU" meter. Even when I increased the setting to
> 999, I
> > > didn't get much more that 1/3 of the way to the 3khz mark. However,
> after
> > > raising it to 999, I could get proper decodes of all of the numeric
> > digits
> > > in the CLI menu. My next step was to remove the 4.7Kohm resistor in the
> > RX
> > > line as shown in the UV 82 node radio tutorial on Hamvoip. That seemed
> to
> > > make no difference at all. Even though I get proper decodes in CLI,
> they
> > > still don't resolve to working commands over the Allstar network. Any
> > other
> > > suggestions? As I mentioned earlier, pre-emphasis and de-emphasis are
> > > currently disabled.
> > >
> > > Brian / KK6DOQ
> > >
> > > On Fri, Mar 29, 2019 at 1:18 PM "Don Backstrom - AA7AU via
> ARM-allstar" <
> > > arm-allstar at hamvoip.org> wrote:
> > >
> > > > On Fri 29-Mar-19 11:37, "B Harvey via ARM-allstar" wrote:
> > > > > I can't test actual
> > > > > levels or wide / narrow mode so I'll have to wait until I get home
> to
> > > try
> > > > > those out.
> > > >
> > > >         From our tech write-up: "If you are having issues ... and are
> > > > experiencing audio levels or DTMF decoding/encoding difficulties,
> use a
> > > > service monitor to check to see if the module is actually programed
> to
> > > > Wideband mode"
> > > >
> > > > > Another thing that occurred to me is that perhaps I'm too close
> > > > > to the node when I'm transmitting from my HT and I may have some
> > > de-sense
> > > > > thing going on.
> > > >
> > > >         That obviously can also give you issues. Also remember *low*
> > > power.
> > > >
> > > >         Doug and David are the experts here, especially on all the
> > other
> > > > settings. I'm just an interested HamVoip user chiming in on DTMF, as
> we
> > > > did battle with those issues for quite some time before discovering
> the
> > > > 818 probs and others like issues.
> > > >
> > > >         One other note on DTMF: on many HTs when you PTT and then key
> > > your
> > > > DTMF
> > > > code in you get output from your HT speaker - which *can* lead to
> real
> > > > feedback probs as your mike is open and listening during PTT. Find
> the
> > > > setting and disable tone output from DTMF entry. Also, watch your
> > > > background noise/conversation/etc at anytime you are using PTT even
> if
> > > > just to key in DTMF - you're OTA!
> > > >
> > > >         Good luck,
> > > >
> > > >         - Don - AA7AU
> > > > _______________________________________________
> > > >
> > > > ARM-allstar mailing list
> > > > ARM-allstar at hamvoip.org
> > > > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> > > >
> > > > Visit the BBB and RPi2/3 web page - http://hamvoip.org
> > > >
> > > _______________________________________________
> > >
> > > ARM-allstar mailing list
> > > ARM-allstar at hamvoip.org
> > > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> > >
> > > Visit the BBB and RPi2/3 web page - http://hamvoip.org
> > >
> > _______________________________________________
> >
> > ARM-allstar mailing list
> > ARM-allstar at hamvoip.org
> > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> >
> > Visit the BBB and RPi2/3 web page - http://hamvoip.org
> >
> _______________________________________________
>
> ARM-allstar mailing list
> ARM-allstar at hamvoip.org
> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>
> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>


More information about the ARM-allstar mailing list