[amsat-bb] Foxtelem and Kenwood TM-V71 signal to noise ratio

[Nitin Muttin]

What I understand from the Decoder manual is that 9600 is for special experiments and under normal conditions the data under voice (DUV) is 200 bps hence i dont think 9600 setting needs to be enabled / wired at the radio. 73
Nitin [VU3TYG]
      From: John Brier <johnbrier at gmail.com>
 To: Scott <scott23192 at gmail.com> 
Cc: AMSAT BB <amsat-bb at amsat.org>
 Sent: Monday, 20 November 2017 1:18 AM
 Subject: Re: [amsat-bb] Foxtelem and Kenwood TM-V71 signal to noise ratio
   
Thanks for trying Scott.

I do have the 9600 setting enabled. I think you can also set which side of
the radio is used for data, and I believe I set it right, but I'm going to
double check.

Thanks for the USB sound card link. I actually have a 10 yr old laptop with
mic/line in that I might try. If I have to use a laptop during the pass I
almost feel like I might as well just go SDR. In general I don't like to
have things anchored to the ground and me, which is why I carry all my gear
on my body.

73, John Brier KG4AKV

On Nov 19, 2017 2:31 PM, "Scott" <scott23192 at gmail.com> wrote:

Hi John.

No decodes here from your audio recording, either.  And the reception was
crystal clear.

Did set the data speed menu option to 9600?  I don't know if the 1200
setting would work with AO-91's DUV data or not; I use an SDR, so my RX
audio is already "in" the computer and connected to FoxTelem via VB Audio
cable.

Also, I have been using the following USB audio adapter for data audio
in/out with success in case you need a device for your computer that can
accomodate "line" level audio input:

https://www.amazon.com/Griffin-Technology-iMic-
original-Adapter/dp/B003Y5D776

73!

-Scott,  K4KDR


===============================

On Sun, Nov 19, 2017 at 2:16 PM, John Brier <johnbrier at gmail.com> wrote:

> Oh interesting. I didn't consider that. I will see if I can hook the
> radio into my laptop directly, or try another recorder, though my
> other recorder does 44.1 KHz only, not 48 KHz like the manual says is
> ideal.
>
> Thanks Paul.
>
> 73, John Brier KG4AKV
>
> On Sun, Nov 19, 2017 at 2:11 PM, Paul Stoetzer <n8hm at arrl.net> wrote:
> > Seems likely that some sort of audio filtering is going on in your
> recorder.
> >
> > 73,
> >
> > Paul, N8HM
> >
> > On Sun, Nov 19, 2017 at 2:07 PM, John Brier <johnbrier at gmail.com> wrote:
> >> I made a cable to tap the 9600 data pin off my Kenwood and I'm trying
> >> to decode telemetry from AO-91.
> >>
> >> I am having trouble getting a continuously clean reception, so I don't
> >> expect frames, which I'm not getting, but parts of the reception are
> >> fine and yet FoxTelem still shows a low S/R of 1.2, 1.5 at best. I am
> >> wondering if there is still some filtering going on. I notice the
> >> peaks of the "bits" are not flat like they are supposed to be
> >> according to the manual:
> >>
> >> https://imgur.com/pfX7cSK
> >>
> >> I am recording the audio off the radio into a Zoom H1 at 48,000 KHz
> 16bit wav.
> >>
> >> Maybe I should try hooking the radio directly up to a computer into
> FoxTelem.
> >>
> >> Here is my recording:
> >>
> >> https://www.dropbox.com/s/ineqhoprz50ljl3/2017-11-19_-_
> 1743_UTC_-_AO-91_-_FM05_-_KG4AKV_just_transmissions.wav?dl=0
> >>
> >> Ideas?
> >>
> >> 73, John Brier KG4AKV
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