With the generous help of another member of this forum, I have Quisk demodulating CW under Raspbian on Raspberry Pi B3 with the Audio Injector stereo sound hat.
However, I can only tune the SoftRock Ensemble RXTX over a very limited range and the frequency reading is not correct. I did not have this problem running Quisk under Windows 7 with the same SoftRock board.
The problem seems to be USB communications between the rPi and SoftRock. Can someone, please, point me towards a solution?
I used the "usbsoftrock" utility to confirm that the Raspberry Pi can communicate with the SoftRock board. The "xtall" and "freq" parameters can be changed and reported back via the "status" and "getfreq" commands. Further, "set freq" changes the signals being observed on the Quisk display, but the Quisk frequency is still incorrect.
Oh, yes, Gary. The whole system works as advertised. If you decide to move forward, let me know if you need any guidance.
My primary goal was to learn why SDR receivers suffer from so much added latency compared to "box" radios like my K3. I've observed latency up to 200ms greater from my Elad FDM-S2 and SoftRock receivers, depending on the associated computing platform.
What I learned is that the "lengths" of the SDR's DSP filters accounts for the delay. Since Jim gives us access to the Quisk source code, I was able to practically eliminate added latency by dramatically "shortening" the filters, without noticeably impairing receiver performance.
Not being a programming type, it took me a while to find the right single number to change, but I now plan to base a new-technology transceiver on the Quisk software platform.
73 -- Brian
On Tue, Aug 14, 2018 at 9:20 PM, Gary123 [via quisk] <[hidden email]> wrote:
Sorry for the too general question. I was referring to how you got the audio injector to work with Quisk and whether you ever got the tuning right.
If you reply to this email, your message will be added to the discussion below:
Well, I have Quisk installed and set up the audio injector. Now I need to mount it and test it. I ahve noticed a lot of latency in the pi. Web pages freeze for a time and even the clock stops advancing. Sometimes it is responsive but more often than not laggy. I had to re-compile quisk as pi python 2.7 is only 32 bit.