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Re: [linrad] RE: Silly question or is it?
Thanks for the excellent discussion on the central discontinuity. I
will save it and read it several times as there is a lot of information
As for the question:
Yes, I just did it again. With  as the choice for 2nd forward FFT
routine my total delay is: 6.96 seconds and the fft2 delay is 2.73
Changing Just Second Forward FFT routine from  to  to :
 gives 17.2 second total delay, 10.92 sec FFT2 delay, 59.4% CPU load
 gives 6.89 second total delay, 2.73 sec FFT2 delay, 61.5% CPU load
 gives 6.90 second total delay, 2.73 sec FFT2 delay, 63.9% CPU load
the delay with  really surprised me! (though I know there is a simple
reason it shoudn't have done so).
Are you sure that nothing was changed in the AFC or baseband parameters?
There should be nearly no difference at all in total delay depending
on the different fft versions.
If the total delay really is different (by more than 0.1 second) on
your fast computer, please give me detailed information because then
you have (again) detected a bug;)
I go into the parameter screen and change it to . I change nothing
else and directly leave the parameter screens by repeatedly hitting
enter and keeping my mouse out of trouble. Now my total delay is 17.22
sec and the fft2 delay is 10.92 seconds.
I go back to  as the choice and the delay is again 6.97 seconds and
the fft delay is 2.73 seconds.
Here are my parameters:
First FFT bandwidth (Hz) 
First FFT window (power of sin) 
First forward FFT version 
First FFT storage time (s) 
First FFT amplitude 
Enable second FFT 
First backward FFT version 
First backward FFT att. N 
Second FFT bandwidth factor in powers of 2 
Second FFT window (power of sin) 
Second forward FFT version 
Second forward FFT att. N 
Second FFT storage time (s) 
Enable AFC/SPUR/DECODE 
AFC lock range Hz 
AFC max drift Hz/minute 
Enable morse decoding 
Max no of spurs to cancel 
Spur timeconstant (0.1sek) 
First mixer bandwidth reduction in powers of 2 
First mixer no of channels 
Baseband storage time (s) 
Output delay margin (0.1sek) 
Output sampling speed (Hz) 
Default output mode 
Audio expander exponent 
A/D speed 
I found this interesting behaviour. The difference in total delays in
on the order of 10.26 seconds.
Let me know what else I can do here. It would be interesting to see if
anyone else sees this behaviour with these parameters.
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Reading, PA 19609