[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] doubt about the tune()
From: |
Eric Blossom |
Subject: |
Re: [Discuss-gnuradio] doubt about the tune() |
Date: |
Wed, 4 Aug 2010 10:14:32 -0700 |
User-agent: |
Mutt/1.5.20 (2009-08-17) |
On Wed, Aug 04, 2010 at 05:08:44PM +0800, intermilan wrote:
>
> hi all:
> I recently run the test_usrp_standard_tx/rx.cc to do some test.and
> after I run the test_usrp_standard_tx.cc, I got the follow information:
> which: 0
> interp: 64
> rf_freq: 2.5e+09
> amp: 30000.000000
> nsamples: 3.2e+07
> Subdevice name is Flex 2400 Tx
> Subdevice freq range: (2.3e+09, 2.7e+09)
> mux: 0x000098
> baseband rate: 2e+06
> target_freq: 2500000000.000000
> ok: true
> r.baseband_freq: 2504000000.000000
> r.dxc_freq: -4000000.000000
> r.residual_freq: 0.000000
> r.inverted: 0
> xfered 3.2e+07 bytes in 4 seconds. 8.002e+06 bytes/sec. cpu time = 0
>
> as you can see, I want to set the frequency at 2.5G(RFX2400) ,but there
> is a parameter called r.basebande=2.504G.I know it is the return valus of the
> tune().but I want to know what is the function of this parameter and how did
> 2.504G come out. can anyone help me to figure it out?
> Besides,why the frequenct of the DUC is set at -4M? how did it come out?
It moves the DC offset 4MHz away from the center of your desired
spectrum. r.baseband_freq + r.dxc_freq = target_freq.
Eric