Hi Raydel,

I stand to be corrected but a these dongles are specified for DVB-T so I dont think they would work for signals using DVB-S modulation.

The signals from the ISS will be at 1.3Msps or 2.0Msps - I believe that only the Technotrend T1600 and T3200 cards have, so far, been identified as being suitable for these very low symbol rates http://www.technotrend.eu/2920/TT-budget__S2-1600.html

It is anticipated that more detailed info for potential ground stations will be made available quite soon.

thanks

Graham G3VZV

-----Original Message----- From: Raydel Abreu Espinet Sent: Tuesday, May 21, 2013 4:41 PM To: [email protected] Subject: [amsat-bb] Question about HamTV

Hello,

About the future HamTV experiment, is it possible to use a cheap RTL DVB-T dongles used or RTLSDR to receive such signals with proper LNA and downconverter. If the downconversion fits the signal on a proper channel does it device is capable of decode the transmitted format???

Thanks,

Raydel --- _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

I thought the whole idea with these SDR "Dongles" is that you could decode practically anything in software. Unless the required bandwidth is too high, and perhaps not in real time, but they can be decoded. For example, people do SSB and FM with them, neither of which are anywhere close to DVB-T modulation.

Couldn't something like that be done with HamTV?

Greg KO6TH

Miguel Barreiro wrote:

Raydel,

Apart from the frequency and signal level differences, DVB-T is a 6-8MHz wide signal with COFDM modulation, using 2k to 8k subcarriers, while DVB-S is a single carrier, 6..36MHz wide signal, usually QPSK or 8PSK. You cannot use a downconverter and a DVB-T receiver to tune into a DVB-S channel.

However, the digital bitstream carried by both is the same - so if you have software analyzers and audio/video players for DVB-T they will work for DVB-S too.

Miguel EA1ICZ

2013/5/21 Raydel Abreu Espinet[email protected]

...

Hello,

About the future HamTV experiment, is it possible to use a cheap RTL DVB-T dongles used or RTLSDR to receive such signals with proper LNA and downconverter. If the downconversion fits the signal on a proper channel does it device is capable of decode the transmitted format???

Thanks,

Raydel

---

Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

---

Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb