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Re: Audio Resampling clicks
Thanks Ben, for the reply!
I've pretty well eliminated my device as the cause and focussed on the resampling method, but I will spend a little more time figuring out how Quisk processes buffers. By measurements, experimentation with modifications to the source code and a little reasoning, it appears that periodic random jumps of up to 1/2 sample value (which the present method creates) are not a good thing. ?Doing this correction to wideband IQ samples just before they are sent to the hardware the way it does, precludes doing any low pass filtering - which would mitigate the spurious transients. Unfortunately, the nasty side effects are not easy to detect with instruments because they are transient and randomized. I'm pretty sure the best thing to do would be to minimize the resampling during actual transmitting. Right now the algorithm runs continually. It probably could be disabled during normal transmissions if the underlying clock error is not too great. This would usually hide the correction because hams usually do low duty cycle transmissions. A bigger "dead band" in the feedback loop might also help by having it run less often. I've been too busy to try it, but I'm going to disable the correction code completely (not the measurement part - just the few lines that interpolate or drop the samples) and try running my high resolution variable codec clock to do the correction instead. I'm fairly certain this will do the resynchronizing without side effects, but it takes a little thought to design the PLL-like software loop that will do the adjustment smoothly. Unfortunately, this would only help hardware like mine and not other use cases. If this works, I'll report back and request an easier way to allow user supplied correction methods to be used by disabling the interpolation/drop via a configuration switch so that it doesn't require recompilation. It would also be nice to have a clean way to access the buffer fill statistics for such methods to use. I'm envisioning something easy to add to the heartbeat method in the hardware object.? My apologies to forcing everyone to follow my missteps and thinking out loud in public about this. I was kind of hoping it would bring more suggestions like yours out of the woodwork. The two clock problem is pervasive in communications and is never easy to fix! M |
Re: Audio Resampling clicks
¿ªÔÆÌåÓýHi Mario, It reminds me of trouble I had in 2020 with Quisk on a Windows laptop, connected to a Softrock (Tayloe) radio via a Behrenger UCA202 ... it may not be the same problem, but I noticed that I/Q data out would sometimes go into what I called "buzz mode" ... it seemed that one of the ping-pong buffers in the driver got disabled, because the output would periodically (regularly every few milliseconds) alternate between normal I/Q data and silence ... made for a nasty radio signal (CW), which I would not have noticed if I hadn't been using an oscilloscope and spectrum analyzer to monitor my output. I did a lot of poking around and experimenting in the sound_wasapi.c file to track it down ... long story short, the problem seemed to be in the driver or hardware, i.e. downstream from Quisk.? Take a look at the function quisk_reset_audio_device() in that file, which resets the driver, and see where it gets called, i.e. how the problem is detected while running.? I don't recall ever figuring out what might have triggered the problem in the driver. Of course, this might not be your problem (different driver on
different OS), but perhaps re-setting your driver might help to
break out of the bad mode. Good luck!! -- Ben, AC2YD -- On 11/4/23 08:47, Mario Vano AE0GL
wrote:
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Re: Feature Request: Add option for Disable PA on each Xvtr Band
¿ªÔÆÌåÓýThat is a reasonable no coding solution.? The main limitation is a program like WSJT-X cannot change bands from, say, HF to 6M or other VHF bands without first stopping the radio and WSJT-X, and restarting each.? I know you have a settings to start WSJT-X on RX0, have not tried it as I often run multiple instances for multiple radios.? ? I am used to my K3 with the 6M and HF antennas and the xvtr interface for the VHF Xvtrs, I just hit the band button or memory and instant change for all bands 160M through 1296.? ?Running a program like WSJT-X can jump between any band like 6M, HF and VHF seamlessly.? In the case of the 5-band Xvtr it switches bands fast and silently with no relays for when I manually scan for contacts during VHF contests. ? The HL2+IOBoard is capable of the same seamless coverage with the RF1 and Aux RF connected to the Xvtr(s) and HF on the ANT jack.? I have the DB9 wired so that I can just swing the Xvtr control cable and the IF coax lines between the K3 and HL2s, one can replace the other now. ? I am a complicated user scenario ?. ?
? From: [email protected] <[email protected]> On Behalf Of
jimahlstrom
Sent: Saturday, November 4, 2023 6:36 AM To: [email protected] Subject: Re: [n2adr-sdr] Feature Request: Add option for Disable PA on each Xvtr Band ? Hello Mike, |
Re: Feature Request: Add option for Disable PA on each Xvtr Band
Hello Mike,
I can program this feature, but I think is is not optimal. The correct approach with Quisk is to create two radios, one for HF and one for transverters. Then select the correct radio when Quisk starts. The HF radio shows only HF bands and the power amp is enabled. The transverter radio shows only VHF and UHF bands, and the power amp is off. If you have transverters that need the power amp, there is a third radio. One problem with controlling the power amp from the band screen is that you probably need to control the RF input on the IO board too. This clutters up the band screen. Is there something wrong with using separate radios? Jim N2ADR |
Audio Resampling clicks
Hi!
I'm trying to chase down some annoying clicks/buzzes in the IQ stream sent in the audio stream sent to my Tayloe style 48khz QSE transmit mixer. I'm quite certain there is no overrun situation or anything like that occurring. Is anyone else seeing problems like this? I notice that the clicks start appearing as soon as the audio resampling fixup routine starts correcting the buffer fill level in "sound.c" around line 524. Until the first time this code runs, the audio is perfect, but once corrections start being made then very serious artifacts start appearing in the audio. ?I'm working on a Pi400 and some Pi4b units under the new "Bookworm" OS, but the problem is identical in the earlier os version. Thanks in advance for any help or advice I can get on this. M |
Re: Congratulations to Jim!
Very pleased, long overdue.
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Show quoted text
Started when I needed a Linux application for Softrock SDR and Jim obliged massively. The N2ADR QEX article which provided the basis for the HiQSDR and now HermesLite2 contributions. 73 ... Sid. On 01/11/2023 13:26, Ben Cahill wrote:
Hi all, --
Sid Boyce ... Hamradio License G3VBV, Keen licensed Private Pilot Retired IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Specialist Microsoft Windows Free Zone - Linux used for all Computing Tasks |
Re: Congratulations to Jim!
Thank you For all your contributions James! On Wed, Nov 1, 2023 at 8:26 AM Ben Cahill <bmcahill@...> wrote: Hi all, |
Re: Congratulations to Jim!
Congratulations, Jim! On Wed, Nov 1, 2023 at 9:37?AM Nick Abramenko RA3PKJ <ra3pkj@...> wrote: I'm very happy for Jim! :))) |
Congratulations to Jim!
Hi all,
I noticed in October 2023 QST magazine, page 65, that Jim Ahlstrom, N2ADR, was recently recognized, by the ARRL Board of Directors, with the ARRL Technical Innovation Award.? Here's a passage from the minutes of their meeting: " WHEREAS, James C. Ahlstrom, N2ADR has made major contributions to ham radio hardware and software by creating the Quisk SDR transceiver, and through designing numerous other innovations within the Hermes Lite 2 SDR hardware transceiver platform. All software products are open-source and free to users; " It's not the first time, either ... a little internet research showed he was recognized with a similar award in 2012: Congratulations, Jim, with many thanks!! -- Ben, AC2YD -- |
Re: Quisk install errors
I had the same problem with pillow when installing previous versions of wxpython. The latest version of pillow is always used automatically. The problem is that the latest version of pillow does not work with previous versions of wxpython. You need to select one of the previous versions of pillow - https://pypi.org/project/Pillow/#history and install it yourself using pip.
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