[Linrad] SDR-IQ USB Limits

["Thomas D. Dean" <speakeasy.org; tomdean@xxxxxxxxxxxxxxxx>]

On Wed, 2009-06-03 at 00:26 +0200, Leif Asbrink wrote:

> Please change 260000 and 300000 in sdr14.c at lines 507 and 880 to 
> something higher and check where the limit is for SDR-IQ on your
> computer. In case it is much above 250 kHz I will make the
> tests different for SDR-14 and SDR-IQ.

In my sdr14.c, the line numbers are different, but, I found them.

I ran several tests, varying the decimation, keeping the FFT BW at 30Hz.
I found a combination that fails.  See the bottom

CIC2, CIC5, RCF, RCF shift, sample clock shift, db
2,2,20,0,0,25 fft1 size 16K
Spectrum Ok
RX A/D Speed Error 252056 Hz (Nominal 833333 Hz)

2,2,15,0,0,25 fft1 size 16K (Nominal 1111111 Hz)
Spectrum Ok
RX A/D Speed Error 253224 Hz (Nominal 1666666 Hz)

2,2,10,0,0,25 fft1 size 32K
Spectrum Wrong - NLK at 24.8 KHz is not visible, just noise
RX A/D Speed Error 253224 Hz (Nominal 3333333 Hz)

2,2,5, 0,0,25 fft1 size 64K
Spectrum Wrong- NLK at 24.8 KHz is not visible, just noise

2,2,2, 0,0,25
Spectrum Wrong- NLK at 24.8 KHz is not visible, just noise

In all cases, I could press X and get to the mode help page and X again
to get to the main menu.

The timer error message seems to be limited around 250KHz.  I started
looking at this, but, 

This seems repeatable.
2,2,30,0,0,25
FFT BW 30
MEMORY ERROR mm=2[56]  data is0 (56)  Call no 198
MEMORY ERROR mm=2[57]  data is0 (57)  Call no 198
MEMORY ERROR mm=2[58]  data is0 (58)  Call no 198
MEMORY ERROR mm=2[59]  data is0 (59)  Call no 198
MEMORY ERROR mm=2[60]  data is0 (60)  Call no 198
MEMORY ERROR mm=2[61]  data is0 (61)  Call no 198
MEMORY ERROR mm=2[62]  data is0 (62)  Call no 198
MEMORY ERROR mm=2[63]  data is0 (63)  Call no 198
Error in fft1,fft2

# ../save-par.sh
Saving par* to /home/tomdean/Radio/Linrad/ParFiles/par200906022130.tgz

Tom


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "Linrad" group.
To post to this group, send email to linrad@xxxxxxxxxxxxxxxx
To unsubscribe from this group, send email to linrad+unsubscribe@xxxxxxxxxxxxxxxx
For more options, visit this group at http://groups.google.com/group/linrad?hl=en
-~----------~----~----~----~------~----~------~--~---


LINRADDARNIL