[amsat-bb] Re: AO-73/FUNcube-1 videos, observations

Patrick STODDARD (WD9EWK/VA7EWK) amsat-bb at wd9ewk.net
Sun Dec 1 18:32:21 PST 2013

Hi Mark!

Thanks for your e-mail.  Since I do lots of satellite
demonstrations and get the questions about what it
takes to work satellites like the new AO-73, I figured
I'd put together some information in those videos and
my -BB posts.  I'll use your message as the one I reply
to, but acknowledge the others who replied to my late-
night post on the -BB and in direct e-mails today.  No
radio tonight, since I have to be in the office early
tomorrow, but I will probably be outside tomorrow night
for at least one of the AO-73 passes.

AC0RA mentioned last night on the western AO-73 pass
that he could receive the transponder and use the
dashboard to receive telemetry at the same time.  Wyatt
didn't go into detail on what he had to do on the laptop
on the air, but he mentioned he used HDSDR with the
dashboard software.  I may follow Hector's (CO6CBF)
suggestion of working the transponder and recording
everything during a pass, then run that through the
dashboard using whatever configuration I need so that
the playback can be piped into the dashboard and decoded.
I may be able to work SSB/CW satellites without a computer
from almost anywhere I go, but the SDR stuff is something
I am trying to (quickly) learn.  Especially when the
dongle's namesake is now in orbit and operational.  :-)

Since I will be at a hamfest on Saturday morning, I may
work on just using the dashboard by itself to copy the
telemetry, to have something else to show off at the
hamfest on AO-73's morning passes (if the transponder is
not turned on), then "worry" about trying to hear the
transponder and receive telemetry with the dashboard

You mentioned that I could work the transponder and
receive telemetry at the same time if I transmit at
500mW.  This would be possible on higher passes based
on my tests in the past week, but is there a reason
why 5W would be too much with the Pro+ dongle and its
filtering along with a diplexer between the radios
and the Elk antenna?  I'm not looking to run more power
than 5W, since I'm not planning to add an amplifier or
replace one of my FT-817NDs with something like an
FT-857 at this point.

To those who suggested I modify one of my FT-817NDs to
have a panadapter interface and then use both the 817
and dongle on the downlink, what advantages would I
have in doing that, instead of just using the dongle
as the downlink receiver?  I apologize if this is a
silly question, but I'm wanting to learn more about
what I can do with this dongle, by itself or alongside
my existing gear.  I'm looking forward to seeing N1JEZ's
article in an upcoming AMSAT Journal, and will look at
the link Mike suggested to learn more about this option.

I haven't even started thinking about getting SatPC32
mixed in with all of this SDR stuff, but know that I
could do that.  I still need to get it working my two
FT-817NDs, something that remains on my satellite "to
do" list.



On Sun, Dec 1, 2013 at 2:12 PM, Mark L. Hammond <marklhammond at gmail.com>wrote:

> Hi Patrick,
> Great sharing of your experiences---thanks!  Nice to have AO-73 operations
> futher characterized.
> Regarding the Funcube Dongle Pro Plus (FCDP+)---you should enjoy the
> experience of learning how to use it!  It's such a neat receiver.
> Some quick thoughts/pointers/questions:
> Are you planning to capture telemetry and work the transponder
> simultaneously during evening passes?  It might work, depending on your
> antenna system, especially if you can get buy with only 500mW uplink.  I'll
> be interested in your experiences with this...
> There is one thing to remember--you'll need two audio streams decoding at
> the same time.  SDR-Radio V2.1 will do this, with "VFO A" and "VFO B".
> They each have separate audio out selections, so you can pipe the telemetry
> to something like VB Audio Virtual Cable into the Dashboard, and the other
> VFO and audio stream to your laptop speakers or headphone jack.  SDR-Radio
> V2.1 also has built in satellite tracking for doppler correction, and you
> can record the pass at the same time!
> On the other hand----if you don't want to try to do telemetry and the
> transponder simultaneously, you have some more options...
> SatPC32 has great DDE support, and you can use that with either HDSDR or
> SDRSharp to tune your FCDP+ as a separate receiver.  It works great, and
> it's pretty easy to do, if you want your receiver following the
> Doppler/frequency from SatPC32.
> Now, if you want to use your FCDP+ as a receiver AND be able to click on a
> frequency and have the transmit match it---that's another trickier setup
> involving HDSDR, SatPC32, and virtual comports.  It works and is slick, but
> it's not for the faint of heart.  You can read about that setup here:
> http://www.tomdoyle.org/FUNcube-SatPC32/FUNcube-SatPC32.html
> I did similar to that writeup by Tom, but found I could do 56k serial port
> speeds just fine.
> Have fun!
> 73,
> So, lots of options..

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