[OZAPRS] Fw: 40M APRS frequencies

Scott Evans vk7hse at gmail.com
Mon Dec 4 11:40:45 AEDT 2017


I've never used Direwolf! I'm a hardware modem guy! and yeah I'm happy
living in the past! 😉

On Mon., 4 Dec. 2017, 11:32 Glen English VK1XX, <
glenlist at pacificmedia.com.au> wrote:

> And TX level shouldnt matter much at all unless you savagely overdrive it
>
> there is only one tone there at a  time.
>
> so there is no IMD
>
> and since the tones are up at 1600 Hz, the harmonics will be outside the
> SSB filter....at least 20dB down.
>
> On an all-digital radio, overdriving may causing aliasing distortion,
> (which would put sh1t everywhere)   if the input of the ADC was heavily
> clipped....  that's about all.
>
> I would like to see a mod in Direwolf though that ramped up the tone
> level over  a few mS as not to hit the ALC hard, often overshooting.
>
> g
>
>
>
> On 4/12/2017 10:45 AM, Scott Evans wrote:
> >
> > Yes I have S9 noise here too but I'm using a vertical so noisy bands
> > kinda comes with the territory! 😉
> >
> >
> > On Mon., 4 Dec. 2017, 09:50 Gavin Rogers,
> > <grogers at vk6hgr.echidna.id.au <mailto:grogers at vk6hgr.echidna.id.au>>
> > wrote:
> >
> >     I'd say mine. I'm using the incredibly technical interface of
> >     using an audio cable from the headphone jack to the sound card :)
> >
> >     The antenna is a long wire, although resonant on 40m, I suffer
> >     from S7-9 noise on all bands at all times (suburban areas, woo
> >     hoo!) , hence my limited HF experience.
> >
> >
> >
> >     On 4 December 2017 6:41:11 am AWST, Scott Evans <vk7hse at gmail.com
> >     <mailto:vk7hse at gmail.com>> wrote:
> >
> >         Hi Gavin,
> >
> >         Curious, but the mention of the audio level being too high, is
> >         that saying that mine is or yours? 🤔
> >
> >
> >         On Mon., 4 Dec. 2017, 09:25 Gavin Rogers,
> >         <grogers at vk6hgr.echidna.id.au
> >         <mailto:grogers at vk6hgr.echidna.id.au>> wrote:
> >
> >             Captured a handful of frames last night here in Perth on
> >             40m. I guess it
> >             works! Also is my first 40m digital RX, so that's nice :)
> >
> >             VK7HSE-4 audio level = 139(11/14)   [NONE]   __||___
> >             Audio input level is too high.  Reduce so most stations
> >             are around 50.
> >             [0.2] VK7HSE-4>APRX29,WIDE2-1:!4259.56SI14718.64E#RasPi
> >             iGate & Digi
> >             Position, OVERLAY DIGI (green star) w/overlay I, >40 APRSmax
> >             S 42 59.5600, E 147 18.6400
> >             RasPi iGate & Digi
> >
> >             VK7HSE-4 audio level = 158(11/19)   [SINGLE] __::___
> >             Audio input level is too high.  Reduce so most stations
> >             are around 50.
> >             [0.2] VK7HSE-4>APRX29,WIDE2-1:!4259.56SI14718.64E#RasPi
> >             iGate & Digi
> >             Position, OVERLAY DIGI (green star) w/overlay I, >40 APRSmax
> >             S 42 59.5600, E 147 18.6400
> >             RasPi iGate & Digi
> >
> >
> >
> >             73
> >             Gavin
> >             VK6HGR
> >
> >             On 3/12/2017 4:00 PM, Gavin Rogers wrote:
> >             > On 3/12/2017 3:56 PM, Josh wrote:
> >             >> Thanks Gerard.
> >             >>
> >             >> I had a minor issue with direwolf using the wrong tones
> >             earlier, it
> >             >> appears that
> >             >> the config line "MODEM 300" will cause 1600 & 1800
> >             tones to be used but
> >             >> "MODEM 300 # [comment]" causes 1200 & 1800 Hz tones.
> >             > Try using
> >             > MODEM 300 7 at 30
> >             >
> >             > This will set up a number of modem frequency groups
> >             that'll help with
> >             > (mis)tuning:
> >             >
> >             > Channel 0: 300 baud, AFSK 1600 & 1800 Hz, D, 48000
> >             sample rate
> >             >         0.0: D 1510 & 1710
> >             >         0.1: D 1540 & 1740
> >             >         0.2: D 1570 & 1770
> >             >         0.3: D 1600 & 1800
> >             >         0.4: D 1630 & 1830
> >             >         0.5: D 1660 & 1860
> >             >         0.6: D 1690 & 1890
> >             >
> >             > Fairly unlikely I'll get anything here on Perth on 40m
> >             on packet with
> >             > my antenna but I'm curious on the performance of
> >             Direwolf on HF so
> >             > I'll have my station listening for a few days.
> >             >
> >             > 73
> >             > Gavin
> >             > VK6HGR
> >             >
> >
> >             --
> >
> >                    Gavin Rogers                     |  Amateur radio
> >             station VK6HGR
> >             http://www.livingwaters.com/good  | http://vk6hgr.ampr.org/
> >                             MSN/Skype/Email:
> >             grogers at vk6hgr.echidna.id.au
> >             <mailto:grogers at vk6hgr.echidna.id.au>
> >
> >             _______________________________________________
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> >             http://lists.aprs.net.au/mailman/listinfo/ozaprs
> >
> >
> >     --
> >     Gavin Rogers mobile
> >     _______________________________________________
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> >
> >
> >
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