[amsat-bb] AO-85 high speed data/telemetry testing Dec. 29-30, 2015

[Burns Fisher]

One comment about the "constant carrier".  Remember that with FM, there
*is* a constant carrier as long as "PTT" is "pressed".  And on AO-85 the
carrier stays on for 30 seconds after the last time it heard a 67-Hz tone.
And in addition, there is no squelch on the receiver (for the same reason
you turn squelch off when listening on the ground---to be able to pick up
weak signals better).  So I wonder if you hear the carrier still on and
repeating noise from the the uplink when no one was talking?  That is a
pretty wide use of spectrum because it is pretty loud.

73,

Burns W2BFJ

On Sat, Dec 26, 2015 at 11:06 PM, Scott <scott23192 at gmail.com> wrote:

> Nice overhead pass of AO-85 just now; decoded 52 packets with v1.03a of
> FoxTelem in auto mode.
>
> Question:   Even though I heard a couple of stations attempting to work the
> voice transponder, there seemed to be a constant carrier that looked like
> data to me.  Quite different from the sub-audio data that I have copied in
> the past.   On the SDR waterfall, it occupied maybe 12-15k KHz of the RF
> spectrum, I believe.   Has something changed since the last time I
> downloaded AO-85 telemetry?  Any idea what I was seeing?  Were BOTH the
> voice transponder and high-speed data on at the same time somehow?
>
> IQ recording available if needed.
>
> Thanks!
>
> -Scott,  K4KDR   FM17es
> Montpelier, VA  USA
>
> On Fri, Dec 25, 2015 at 12:59 PM, Mark L. Hammond <marklhammond at gmail.com>
> wrote:
>
> > Hello All,
> >
> > Greetings.  In an effort to test a new autobaud selection feature in
> > FoxTelem 1.03, the Operations Team will be conducting some experimental
> > sessions with AO-85 next week (Dec. 29 and 30, 2015).
> >
> > Telemetry collectors in/near the US are encouraged to participate and
> help
> > with testing the autobaud selection feature by installing the 1.03 test
> > version available here:
> > http://amsat.us/FoxTelem/test/
> >
> > I suggest you do a clean/fresh install in a new folder so you can always
> > go back to 1.02 if you prefer.  (It's possible to upgrade only the new
> > files, but if you have to ask how, you'd better not do it ;))
> >
> > You'll see a new "Auto" button option, next to the Low and High speed
> > buttons; use it.
> >
> > Specifically, during the following passes we'll be switching from the
> > current voice transponder operation with low speed telemetry, to high
> speed
> > telemetry (Note: in high speed mode, voice operations are OFF).  The
> > switches will take place about every minute or two during the pass.
> Please
> > avoid making contacts during these testing periods.
> >
> >
> >  29.12.2015  AO-85        11:19 11:32 UTC
> >  29.12.2015  AO-85        13:00 13:12 UTC
> >
> >  30.12.2015  AO-85        11:45 11:59 UTC
> >
> >
> > During 2016, two or three more Fox satellites are planned for launch into
> > orbit, and these birds will need to operate in high speed data mode from
> > time to time to download space photos, experimental data, etc.  Taking
> > advantage of some in orbit testing with Fox-1A/AO-85 will be very helpful
> > to the further development of the FoxTelem ground station software.  All
> > the thanks go to Chris Thompson AC2CZ for his extraordinary efforts on
> the
> > telemetry software (both client and server side)!
> >
> > Feedback about your experiences will be appreciated.  Email to the list
> is
> > preferred so all can learn.
> >
> > 73,
> >
> >
> >
> >
> > Mark L. Hammond  [N8MH]
> > _______________________________________________
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> > expressed
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> >
> _______________________________________________
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