issue with changing frequency

All bug reports here please
jdow
Posts: 798
Joined: Mon Aug 10, 2020 8:17 pm

Re: issue with changing frequency

#11

Unread post by jdow »

Which version of SDRC? (If not the latest, get the latest.) What else is running on the computer behind SDRC? Do you have the system running in a low power mode for some reason? Your description suggests SDRC is falling behind in its message loops or else something is interrupting the message loops. Are you sure you are not infected with a virus that is doing something like bitcoin mining in the background? What is the CPU and GPU usage level?

{^_^}

Max
Posts: 853
Joined: Thu Aug 13, 2020 9:47 am

Re: issue with changing frequency

#12

Unread post by Max »

jdow wrote: Sun Jul 25, 2021 8:33 am What is the CPU and GPU usage level?

{^_^}
Joanne he's using 3.0.28.

In his video, watch the audio delay after changing stations. It quickly builds up to the maximum displayable in the window (bottom right of screen), maxing out around 77mS after each station change. Something odd happening here. For info, when I do a video recording on my 12 year old PC (yes, it's got a decent GPU, granted) I have CPU 10%, GPU 12%, Audio delay 28ms. It does just look like that PC is struggling somewhere. The audio delay is strangely high.
Delay.JPG
When I am not video recording on SDRC and receiving FM stereo, my figures are CPU 0.5% GPU 4.4% Audio delay 27ms

Kanakun, have you tried it without the DAC, so just on the standard sound card?

Max

Kanakun
Posts: 15
Joined: Wed Jul 21, 2021 6:56 am

Re: issue with changing frequency

#13

Unread post by Kanakun »

Max wrote: Sun Jul 25, 2021 9:10 am In his video, watch the audio delay after changing stations. It quickly builds up to the maximum displayable in the window (bottom right of screen), maxing out around 77mS after each station change. Something odd happening here. For info, when I do a video recording on my 12 year old PC (yes, it's got a decent GPU, granted) I have CPU 10%, GPU 12%, Audio delay 28ms. It does just look like that PC is struggling somewhere. The audio delay is strangely high.

When I am not video recording on SDRC and receiving FM stereo, my figures are CPU 0.5% GPU 4.4% Audio delay 27ms

Kanakun, have you tried it without the DAC, so just on the standard sound card?

Max
the gpu usage was high because i was recording using high bandwidth settings i have attached an image of my normal usage. i just tried it without my dac and made no difference and still glitches. i still dont know about audio delay
Attachments
Regular CPU/GPU Usage
Regular CPU/GPU Usage
image_2021-07-25_180929.png (1.39 KiB) Viewed 409 times

jdow
Posts: 798
Joined: Mon Aug 10, 2020 8:17 pm

Re: issue with changing frequency

#14

Unread post by jdow »

This is likely another issue with MFC, Microsoft Foundation Classes. They have what is called a message loop. If that loop gets stuffed you get into trouble. That can happen when a message takes too long to be completely processed. More messages cue up and if they cannot be serviced fast enough response to changes can become very slow. I've seen this before with SDRC. Simon seems to have fixed that. But, I am also running a much faster system than when I saw it.

You should make sure you are not running in a power saving mode. That is the processor should always be running at full speed until you can prove that is not needed. (It takes time to switch, which can pack you up.) You should reduce window sizes. You should reduce spectrum update rates. If the lowest setting for update rates still cause problems I am not sure what to suggest. Either way, if these help or not let us know here for general information helping others. With this fast system I have turning of "be kind to the environment and electric bill" settings in Windows settings makes a big difference in this regard.

{^_^}

Kanakun
Posts: 15
Joined: Wed Jul 21, 2021 6:56 am

Re: issue with changing frequency

#15

Unread post by Kanakun »

jdow wrote: Mon Jul 26, 2021 10:56 am This is likely another issue with MFC, Microsoft Foundation Classes. They have what is called a message loop. If that loop gets stuffed you get into trouble. That can happen when a message takes too long to be completely processed. More messages cue up and if they cannot be serviced fast enough response to changes can become very slow. I've seen this before with SDRC. Simon seems to have fixed that. But, I am also running a much faster system than when I saw it.
{^_^}
im not sure if this quite the issue in my case because in another sdr app that i tried using to see if it was just this app i got this error
Error
Error
image_2021-07-26_102955.png (10.92 KiB) Viewed 387 times
and it seems to be a usb error

jdow
Posts: 798
Joined: Mon Aug 10, 2020 8:17 pm

Re: issue with changing frequency

#16

Unread post by jdow »

2.4 Msps should work. Now, make sure the application does not expect manual entry of the sample rate using the (perverted) European number separators rather than good old (chauvinistic) American '.' for decimal point and "," for thousands. Most applications simply supply a drop list of known workable values.

If you get that kind of result from SDRC you can remove the dongle, reinsert it, and try again. If you are working in SDRSharp, for example, you must exit SDRSharp, remove and reinsert the dongle, reload SDRSharp and try again. RTLSDR dongles have an unhealthy habit of falling into nearly catatonic states in which they are nearly useless.

What sample rate are you using in SDRC? I rather highly recommend 2.4 Msps as the highest sample rate that is very generally reliable. (At least for the 6 dongles I have at the moment. Um, make that 7. They are useful for FM Broadcast background music, monitoring weather dongles, and so forth. For anything more serious my AirSpys have me highly pleased if not giggling with joy.)

{^_^}

Kanakun
Posts: 15
Joined: Wed Jul 21, 2021 6:56 am

Re: issue with changing frequency

#17

Unread post by Kanakun »

jdow wrote: Wed Jul 28, 2021 11:34 am What sample rate are you using in SDRC? I rather highly recommend 2.4 Msps as the highest sample rate that is very generally reliable.
i run it at 1 Mb/s so nothing crazy idk why it not working

jdow
Posts: 798
Joined: Mon Aug 10, 2020 8:17 pm

Re: issue with changing frequency

#18

Unread post by jdow »

Try 2.4 Msps just for jollies. (Chiefly because I *know* that works with SDRC. I've not tried 1 Msps because 2.4 Msps gives me the equivalent of better part of another bit of sampling precision. That is generally a good thing for dynamic range.)

Also switch OFF ALL AGC in the dongle. Bring RF Gain off AGC to about 19 dB. The internal AGC remains off. If the signals are extremely strong you may need to reduce gain from the 19 dB, which is near optimum as a compromise between strong signals and sensitivity. With really strong signals sacrifice sensitivity. Bring it down. I am running a continuous SDRSharp on an rtlsdr dongle for background music. It is set to 9 dB since some interfering signals are annoyingly strong. Then see if you get this effect. It could be a simple overload effect within the dongle's front end. IMD can give you strange effects.

{^_^}

Kanakun
Posts: 15
Joined: Wed Jul 21, 2021 6:56 am

Re: issue with changing frequency

#19

Unread post by Kanakun »

jdow wrote: Fri Jul 30, 2021 10:50 am Try 2.4 Msps just for jollies. (Chiefly because I *know* that works with SDRC. I've not tried 1 Msps because 2.4 Msps gives me the equivalent of better part of another bit of sampling precision. That is generally a good thing for dynamic range.)

Also switch OFF ALL AGC in the dongle. Bring RF Gain off AGC to about 19 dB. The internal AGC remains off. If the signals are extremely strong you may need to reduce gain from the 19 dB, which is near optimum as a compromise between strong signals and sensitivity. With really strong signals sacrifice sensitivity. Bring it down. I am running a continuous SDRSharp on an rtlsdr dongle for background music. It is set to 9 dB since some interfering signals are annoyingly strong. Then see if you get this effect. It could be a simple overload effect within the dongle's front end. IMD can give you strange effects.

{^_^}
sorry for late response i tried this but it still fails i do not believe that the rtl-sdr is to blame because as i mentioned in an earlier post it works fine on my laptop

jdow
Posts: 798
Joined: Mon Aug 10, 2020 8:17 pm

Re: issue with changing frequency

#20

Unread post by jdow »

I was trying to isolate one more level. I figure it may be a USB issue. However, on rereading I don't notice you saying what frequency you are moving to. There is a setting in the rtlsdr property pages that allows automatic switching to the (pathetic) HF modes. If that is not set and you try to select HF, it's not going to work. I *never* use that mode so I don't often think of it.

{^_^}

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