Yes it does. All required parameters are described in the User Manual Addendum including this one.

Good to know you have it solved. Stay safe.

Thank you Old Man

73,

Gordan

Not so much of the "Old" thank you!

Hello fellas,
I have been doing some tests but I have tried all of the things suggested here and makes no difference. Still a wide dirt y start to the signal (when TUNE is used in WSJT-x).
I am now convinced that it is the USBPORT driver as I have been analysing the latency on it using a piece of software called latencyMon.
It shows the USBport.sys driver causing huge latency. Here is a screen shot when WSJT-x is running TUNE into a dummy load, all VAC settings correct as per discussion here.





Also when I check the USB ports in device manager I see the enhanced USB hub and another USB port on the same IRQ (16) which 'could' be causing the issue.



The problem is this HP XW6600 workstation will not allow me to make manual changes to the IRQs to test if there is a conflict.
I have updated all the drivers.
This is drastic but I'm now considering migrating to win10........gulp.
Jonathan

Hi,
This is how my signal looks sometimes

Hi @all,
i have also problems with VAC on a good Windows 10 System (This email address is being protected from spambots. You need JavaScript enabled to view it. GHz, 16GB, SSD´s, GBit LAN, GTX1070 ).

I´m using VAC 4.62 (full) and get cracks while transmitting and short stuttering on receiving (SunSDR2 Pro).
What i have done in the past:
- installed like addendum, no fix
- tried another vac software, no fix
- investigated network to transceiver (pingplotter), no packetloss, low ping
- checked PC, maybe IO problem, lags, LAN driver, cpu loads etc..., all OK so no fix
- played with audio buffers, 16/24Bit, no fix
- tried another router and GBit LAN-Switch
- installed on my MacBookPro @Mojave, FIX, no stuttering, no cracks - but i will work with Windows
- installed everything on a clean Windows 10 Gaming Notebook, the same, unusable in WLAN, some stutters and cracks with LAN
This problem is not since the last few Windows Updates, it´s over the last years (i had a SunSDR QRP in 2015 and there was the same trouble).

Anyone has a solution to fix this cracks and stutters on rx/tx 100%?

73 and stay healthy

Hi Albert,

very useful to know indeed so thanks for passing this info along. Good to know (again) that it's not my config !!
Windows is the clear problem here but it's impossible for me to solve it on my current Win7 64 bit as I cannot change the IRQ settings at all to test it.
Oh well.
Cheers all.
jonathan

I'm also getting intermittent clicks when using digi-modes (wsjtx, fldigi).
I'm on Ubuntu Linux, and was originally using Pulseaudio (sink/source). I turned off pulsaudio and setup Alsa loopback devices (which improved stability, but not this click issue).
Then used the arecord command to record the audio output that fldigi was sending to the alsa loopback device to a wav file - and there are no clicks - clean recording.
So, I think it is probably in ExpertSDR2 that these clicks are appearing.

I see the clicks in the Analyzer before and after modulation, and can confirm they are transmitted (as viewed on another receiver)
These clicks cover the whole TX audio bandwidth, so will cause minor interferance with other stations (e.g. on FT8)

ExpertSDR2-1.3.1 Update 5
Ubuntu 18.04
Sample Rate: 48KHz
Buffer: 2048

Will Update 6 resolve this issue when it is released for Linux?

if you want to clean up your tx signal even more change the TX Filter taps to 4096 in EESDR2 for Dig mode I also recommend setting the SSB taps to 4096 as a minimum and preferably to 7168 when observing TX signals on spectrum scope or another SDR panadater you will notice a difference in signal cleanliness. The default vale in my opinion is set to low, unless you have a non worthy PC it should be set double the default values at minimum

cheers for that - searched around and found this sunsdr.eu/wp-content/uploads/sites/2/2016/04/Filter-Shape-Factor.pdf
Still getting the clicks, but will play with it...

Ok i've been playing with this issue. I find that the clicks in the audio during TX (from whatever software, e.g. fldigi, wsjtx, etc) get worse with smaller Audio sample size settings in ExpertSDR2 VAC.

I've tested recording using arecord to a wav file and these clicks are not present, so they aren't coming from the modem software, or the alsa loopback devices.

Attached is a screenshot of some Olivia-32/1k from fldigi with the waterfall turned on on TX. It clearly shows the clicks across the audio bandwidth.

I'm wondering if it might be possible to allow for larger audio sample sizes, e.g. 4096, 8192 in a future release?

My PC is hardly a mediocre spec: 16 CPU Cores/32 threads and 128MBs RAM, SSD drives etc...

Breakthrough!!!

Installing the Linux Low Latency Kernel (linux-image-lowlatency-hwe-18.04) has massively improved the data mode audio quality - I'm running FT8 now from WSJTX and the clicks are now quite rare. Also monitoring on an SDR and the signal looks clean.