Capture ADSL signal with TV card?

GNU Radio
1

Hi,

do you think it is possible to use a CX2388x based TV card ( see
Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos ) to capture the
signal of an ADSL2+ Annex B line? Annex B uses the frequency range
from 138kHz to 2,2 MHz.

Looking forward to your comments.

Torsten

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2

Torsten Strelow wrote am 2008-03-28 06:40:

Hi,

do you think it is possible to use a CX2388x based TV card ( see
Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos ) to capture the
signal of an ADSL2+ Annex B line? Annex B uses the frequency range
from 138kHz to 2,2 MHz.

Hello Thorsten

Your referenced page tells us that your tuner has a bandwidth of 30MHz,
which is fine, and can be tuned from 50-850MHz. You want to capture from
about 0 to 2.5 MHz. This is clearly out of the tuning range.
It says something about a 10.7MHz intermediate frequency.

You need some device to get your ADSL-signal in the tuning range, or to
the IF of 10.7 MHz, but this is probably more difficult, as you need to
connect to some internal line and not the default input (antenna in).

Patrick

Engineers motto: cheap, good, fast: choose any two
Patrick S.
Student of Telematik, Techn. University Graz, Austria

3

Hi,

The CX2388x sampling rate is 27 MHz and has a DC
blocking capacitor input. You can try applying the
ADSL direct to its input with the correct signal
level. My concern is more to the noise and the
resolution of the ADC which is currently 8 bit.

Regards,
Hew

— Patrick S. [email protected]
wrote:

You need some device to get your ADSL-signal in the
tuning range, or to
the IF of 10.7 MHz, but this is probably more
difficult, as you need to
connect to some internal line and not the default
input (antenna in).

Patrick

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