Re: [Discuss-gnuradio] Gradual loss of amplitude as flowgraph runs

2015-08-18 Thread Matt Ettus
Take a look at the phase rotator in the frequency translating FIR filter. Is it done with sine/cos lookups or is it a rotating phasor? Rotating phasors can lose amplitude due to finite precision effects. Matt On Fri, Aug 14, 2015 at 1:57 PM, John Ackermann N8UR j...@febo.com wrote: Still

Re: [Discuss-gnuradio] Gradual loss of amplitude as flowgraph runs

2015-08-17 Thread Tom Rondeau
On Fri, Aug 14, 2015 at 4:57 PM, John Ackermann N8UR j...@febo.com wrote: Still working with the polyphase channelizer program. While everything works, there is something very strange: the output amplitude slowly drops the longer the program runs. As near I can tell, this happens in or

[Discuss-gnuradio] Gradual loss of amplitude as flowgraph runs

2015-08-14 Thread John Ackermann N8UR
Still working with the polyphase channelizer program. While everything works, there is something very strange: the output amplitude slowly drops the longer the program runs. As near I can tell, this happens in or following the frequency translating FFT block. To test, I stripped the