[Discuss-gnuradio] Power，Bandwi dth and spectrum switch problems

[Johnson_lu]

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?

2、How do I know bandwidth of transmission and reception channels in
tunnel.py? 

3、I am using an USRP2 with Gnu Radio and XCVR2450 as daughterboard. I want
to switch frequency among different channels 2.4G~2.5G. However, I find that
switch only can succeed about 20 times, then fails. 
The python code is: 
        self.tb.lock()             
        ok = self.tb.txpath.set_freq(new_freq) 
        if not ok: 
            print "Failed to set Tx frequency" 
            raise SystemExit 
        ok = self.tb.rxpath.set_freq(new_freq) 
        if not ok: 
            print "Failed to set Rx frequency" 
            raise SystemExit                     
        self.tb.unlock() 


-- 
View this message in context: 
http://old.nabble.com/Power%EF%BC%8CBandwidth-and-spectrum-switch-problems-tp29031239p29031239.html
Sent from the GnuRadio mailing list archive at Nabble.com.