BATC Forum

Hi All,

I am in the market for a simple, low cost (<US$100) DVB-S real time constellation display. Happy to use a USB device attached to a PC running XP or Linux.

Might be possible using an RTLxxxx series USB SDR RX frontend (don't need LNB power), or a DVB-S USB tuner stick + clever software.

Any thoughts ?

-Mark

Hi Mark,

The only cheap way to see it as far as i'm aware is Tutioune software with certain PCI cards.
http://www.vivadatv.org/page.php?p=tutioune-en

The rtl sdr dongles may be able to see up to 2Ms rates but nothing higher, needs some software to show it... an interesting project

Rob

Just had a go with GNU Radio and you can easily show the constellation of a 1 and 2 Ms QPSK signal using the Realtek DVB sdr dongle (RTL2832/R820)
2Ms looks a bit stretched in amplitude probably due to bandwidth? but 1Ms looks ok, see attached image.

No idea how accurate this is but it does show what is going on without too much trouble, GNU Radio is a big download/long install if you have not already used it!

Rob

Thanks Rob.