Sound Card and Linux Driver

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ZR6AIC
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Joined: Mon Dec 31, 2012 10:07 am

Sound Card and Linux Driver

Post by ZR6AIC »

Your system works very well and I am interested in the sound card you are using to get such a wide band with (192k and Faster)
What sound card are you using to get the wide band with and what Linux driver do you use with the card (ALSA or OSS)
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yo3ggx
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Re: Sound Card and Linux Driver

Post by yo3ggx »

Hi,

I'm using Asus XONAR D1 @192 KHz for 80/40/20m and internal motherboard soundcard (ALC888 based, 96KHz) for the 30m band.
I'm using the ALSA drivers available in the OS (Fedora 15). OSS can be used too , but ALSA gave the the advantage of sharing the sound card with the recorder.
In this way I'm able to record a full band and to have the websdr server functional in the same time (it takes about 2GB/h for 192KHz bandwidth).

Hope this helps.

Happy New Year!

Dan YO32GGX
ZR6AIC
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Joined: Mon Dec 31, 2012 10:07 am

Re: Sound Card and Linux Driver

Post by ZR6AIC »

Thanks Dan

Just one more question do you possibly have the details for Alsa driver details of your .asoundrc configuration for the ASUS XONAR D1
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yo3ggx
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Re: Sound Card and Linux Driver

Post by yo3ggx »

Hi,

XONAR D1 uses the following driver: snd_virtuoso. (channels 1,2 and 3)
Internal Realtek ALC888 uses the following driver: snd_hda_audio (channel 0)

I'm using the following asound.conf file (relevant part):

pcm.card0 {
type hw
card 0
}

pcm.dmixer {
type dmix
ipc_key 1024
slave {
pcm "hw:0,0"
}
}
ctl.mixer0 {
type hw
card 0
}
pcm.sdr80 {
type dsnoop
ipc_key 34514
ipc_perm 0666
slave {
pcm "hw:1,0,0"
rate 192000
}
}
pcm.sdr30 {
type dsnoop
ipc_key 34512
ipc_perm 0666
slave {
pcm "hw:0,2,0"
rate 96000
format S16_LE
channels 2
}
}
pcm.sdr40 {
type dsnoop
ipc_key 38214
ipc_perm 0666
slave {
pcm "hw:2"
rate 192000
}
}
pcm.sdr20 {
type dsnoop
ipc_key 34992
ipc_perm 0666
slave {
pcm "hw:3"
rate 192000
}
}


To access the channels in ALSA use: the following virtual devices:
$sdr80
$sdr40
$sdr30
$sdr20

Hope this help.

73 Dan YO3GGX
dl3seh
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Re: Sound Card and Linux Driver

Post by dl3seh »

Hi,

I'd like to know how you can get ~190khz reception bandwidth out of a 192khz card? I thought maximum reception frequency=sampling rate/2

Iam very interested in building my own sdr server, but for VLF.

Did I understand that right that the Xonar card has 3 simulaneously usable inputs?
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yo3ggx
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Re: Sound Card and Linux Driver

Post by yo3ggx »

Hi,
dl3seh wrote: I'd like to know how you can get ~190khz reception bandwidth out of a 192khz card? I thought maximum reception frequency=sampling rate/2
We are talking about 2 channels (I/Q), at 90deg one from the other.
Iam very interested in building my own sdr server, but for VLF.

Did I understand that right that the Xonar card has 3 simulaneously usable inputs?
You just need to contact Pieter, the author of WebSDR software and ask for a copy of the server files.
XNAR-D1 card has only one ADC, so only one channel, available through 2 inputs, so you can connect only one SDR receiver to a card.
The soundcard on my mtherboard (based on Realtek ALC888) has 2 channels which can be used symultaneous, but at only 96KHz.

Hope this clarifies your questions.

73 Dan YO3GGX
dl3seh
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Re: Sound Card and Linux Driver

Post by dl3seh »

I contacted him already, but still not sure which receiver to use. I would also like to cover the shortwave radio bands, but the receivers beeing able to sample 2mhz are too expensive for a poor ham radio operator ;-)

Well, thanks for your advice of I/Q sampling never thought about that...
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yo3ggx
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Re: Sound Card and Linux Driver

Post by yo3ggx »

dl3seh wrote:I contacted him already, but still not sure which receiver to use. I would also like to cover the shortwave radio bands, but the receivers beeing able to sample 2mhz are too expensive for a poor ham radio operator ;-)
Depends..
My VHF WebSDR covering the full 2m band is using a 10 Euro DVB-T USB stick. The performance is not spectacular (only 8 bit ADC and no input filter at all), but it can cover from 65 to 1700 MHz.

If you want to cover HF, the cheapest and very good option is Softrock Lite II, like the ones used in my 80/40/30/20m WebSDR.

73 Dan YO3GGX
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er1ac
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Re: Sound Card and Linux Driver

Post by er1ac »

Hi Dan,

I want to make a websdr server for my ER region and have to choose one sound card among many types.
Could you help me select one, please.

Websdr server is supposed to be based on Linux: 3 band websdr - 80m (ssb portion), 40m, 20m.

Which are the most optimal, in your opinion and which ones should I avoid ?

Thanks in advance for your advice !
73 de er1ac

P.S. here is a list (prices are from lowest to highest)

1. Ensonic ES1371 PCI Sound Card
2. Diamond ESS Maestro-2 ES1968S PCI Sound Card
3. Yamaha YMF724E-V PCI Sound Card
4. Creative CT4750 PCI Sound Card
5. Creative CT4810 PCI Sound Card
6. USB 2.0 Virtual 7.1 Channel 3D Audio Sound Card
7. Creative Audigy SB0090 24-bit Proffesional PCI Sound Card
8. Creative Labs SB0410 PCI Sound Card
9. Creative X-Fi SB0790 PCI Sound Card
10. Creative Audigy 2 ZS SB0350 24-bit Proffesional PCI Sound Card
11. Creative SB0770 24-bit Proffesional PCI Sound Card
12. Asus Xonar DGX (ASM) Proffesional PCI-E Sound Card New item
13. Asus Xonar DG Dolby Home Theater PCI 5.1 & Headphone Amp HiFi Soundcard w/ Driver Accs New item
14. Asus Supreme FX Proffesional X-Fi PCI-E Sound Card
15. Asus Sound Card XONAR_U3/UAD/B/A Xonar U3 USB
16. M-Audio Audiophile 24/96 2000 Rev-A2 Proffesional PCI Sound Card - only the card (no cables)
17. Creative Audigy 2 ZS Notebook 24-bit Proffesional PCMCIA Sound Card with cables
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yo3ggx
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Re: Sound Card and Linux Driver

Post by yo3ggx »

Hi,

My experience with Creative cards and SDR was not good at all. Because of the filtered inputs, the results are very bad.
What I can recommend is Asus Xonar D1 (is an older model), excellent cards for SDR.
Very good results with the ALC889 based integrated soundcards on some motherboards too. The big advantage is the cost, the full motherboard, with 3 audio in channels of 192KHz/24bit is cheaper than a good PCI soundcard.

Avoid USB cards as you will not be able to get more than 96000Hz/16bit on linux.

Hope this help.

73 Dan YO3GGX
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