On 06/30/2010 08:05 PM, Eric Blossom wrote: > On Tue, Jun 29, 2010 at 11:23:36PM -0700, Johnson_lu wrote: > >> Hi guys， >> Could anybody can help me for these problems？ >> 1、I varied Tx_amplitude from 0.1 to 1 and measured the output with a >> spectrum analyzer. But the changes are very little. The output is almost the >> same when Tx_amplitude is 0.1 and 1. How can I reduce the transmit power to >> a very little value? >> All else being equal that should produce a 10dB change in signal power, unless *something* in the chain is already at saturation due to other factors in the Tx chain. Keep in mind that a 10dB change on a logarithmic scale isn't very much.
>> 2、How do I know bandwidth of transmission and reception channels in >> tunnel.py? >> There seem to be *two* versions of tunnel.py in the examples--which one are you talking about? Have you put the output of the transmit side on a spectrum analyser? That would tell you unambiguously what the bandwidth is, but also careful and knowledgeable inspection of the code will tell you what the theoretical bandwidth is. -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
