Re: [digitalradio] Re: Good USB sound card ?
I use a CHEAP usb sound card adaptor ( 8 EUROS) on one of my old Dell laptops which has no soundcard sucessfully for pskmail/puppy linux. Rein PA0R I would be interested to know if Linux even supports these cheap USB sound devices? I did run Linux in the shack for a while and unfortunately sold one of the original RigExpert devices because it wasn't usable under Linux and at the time I though I wouldn't revert back to Windows. But in the end I did as apart from Fldigi most of the ham software on Linux is second rate compared to that available for Windows and I got fed up at not being able to try some newly announced thing that came only in a Windows version. Julian, G4ILO --- In digitalradio@yahoogroups.com, Rik van Riel wrote: On 08/14/2010 02:15 PM, g4ilo wrote: Well, that isn't my experience. Regardless of the chip set used, it's the entire product including the drivers that will determine the performance. My suspicion is that these devices run at a fixed sampling rate, and that resampling to the rate requested by the software is carried out by the drivers. Not an issue for me since I run Linux and fldigi. The digital mode program fldigi simply gets the audio off the device at one of the native sampling rates of the device and does good quality sample rate conversion internally. I believe you if you have seen the Windows drivers for the device do a terrible job of sample rate conversion. However, I'm not going to experience that issue myself and am quite happy with the device in my setup :) Personally I don't think it is worth economizing in this area. That I can agree with. -- All rights reversed. http://www.obriensweb.com/digispotter.html Chat, Skeds, and Spots all in one (resize to suit) Facebook= http://www.facebook.com/pages/digitalradio/123270301037522 Yahoo! Groups Links
Re: [digitalradio] Re: Good USB sound card ?
g4ilo wrote: I would be interested to know if Linux even supports these cheap USB sound devices? I did run Linux in the shack for a while and unfortunately sold one of the original RigExpert devices because it wasn't usable under Linux and at the time I though I wouldn't revert back to Windows. But in the end I did as apart from Fldigi most of the ham software on Linux is second rate compared to that available for Windows and I got fed up at not being able to try some newly announced thing that came only in a Windows version. Julian, G4ILO that above is EXACTLY my complaint and major, pet peeve.. I would love to run my digital off my MacPro but none of the software for Winmor, MixW, Telnet has been ported to OS-X that I am aware of. result is, I am either sneaker netting files from the Mac to my doze laptop or sending it to my //MARS/ telnet account then copying the data into an EEI or whatever. sucks. BUT, I feel the same way about what I consider the best email program (Agent by Forte) and my favorite photo program (ACDSee). So, as long as those are in Doze, I have resigned myself to running second rate software on my Mac IF I can even find something comparable. thanks for the thread. If anyone finds a comparable Mac OS-X set of digital programs to replace the MixW, Telnet and Winmor, please post it to this list. to the point of a sound card, I like the SL/USB so much, I bought one for each of my transceivers. so, I can unplug one from the T-41 and plug in another, depending on my needs. Since I got my Pro3, I find it hard to go back to my 480HX except for QSY checking for propagation. 73 chas -- ch...@texas.net k5dam Houston, TX http://militarysignatures.com/signatures/member14013.png --
Re: [digitalradio] Re: Good USB sound card ?
On 08/14/2010 02:15 PM, g4ilo wrote: Well, that isn't my experience. Regardless of the chip set used, it's the entire product including the drivers that will determine the performance. My suspicion is that these devices run at a fixed sampling rate, and that resampling to the rate requested by the software is carried out by the drivers. Not an issue for me since I run Linux and fldigi. The digital mode program fldigi simply gets the audio off the device at one of the native sampling rates of the device and does good quality sample rate conversion internally. I believe you if you have seen the Windows drivers for the device do a terrible job of sample rate conversion. However, I'm not going to experience that issue myself and am quite happy with the device in my setup :) Personally I don't think it is worth economizing in this area. That I can agree with. -- All rights reversed.
Re: [digitalradio] Re: Good USB sound card ?
lør, 14 08 2010 kl. 13:57 +, skrev g4ilo: I had one that looks exactly like that though it was sold under another name, and I could not decode 300baud packet at all with it. When used to play back recordings of very weak EME CW all I could hear was band noise. I did try it on my Echolink node for a bit with no apparent problems. So my opinion is that while these cheap USB sound devices may work fine for normal computer audio they are not a good idea at all for digital modes. You may not even realize why it isn't working, or what weak signals you are missing. Julian, G4ILO In my experience most of the inexpensive USB sound devices I have tested contains either the C-media, USB Headphone Set or USB Audio Codec chip sets, all three yields a signal to noise+signal span of at least 100dB (I've seen as high as 112dB). In any case they are more than good enough for the most demanding digital modes - even EME! Vy 73 de OZ1PIF/5Q2M, Peter * ** Genius is one per cent inspiration, ** ** and ninety-nine per cent** ** perspiration. ** ** -- Thomas A. Edison ** * email: peter(no-spam filler)@frenning.dk http://www.frenning.dk/oz1pif.htm Ph. +45 4619 3239 Snailmail: Peter Frenning Ternevej 23 DK-4130 Viby Sj. Denmark *
Re: [digitalradio] Re: Good USB sound card ?
lør, 14 08 2010 kl. 18:15 +, skrev g4ilo: Well, that isn't my experience. Regardless of the chip set used, it's the entire product including the drivers that will determine the performance. My suspicion is that these devices run at a fixed sampling rate, and that resampling to the rate requested by the software is carried out by the drivers. Resampling can be done accurately, at high CPU cost, or less accurately but more quickly. Any resampling is undesirable, but its effect may not be very noticeable with the slower digital modes because if a weak signal doesn't decode you may think that's just because it is weak. Personally I don't think it is worth economizing in this area. And no, I don't have shares in SignalLink. Julian, G4ILO The Signalink USB (which I recommend myself with the caveats on my homepage), uses one of the same Cheap chips used by the low cost general purpose adapters, in this case the USB Audio Codec. As a class of devices you are certainly correct in your assumption about the drivers, but again, as a class of devices, they support all std. sampling rates from 48000 and down, with one notable exception: 11025 (this became a de facto std many years ago when it was the fastest rate these newfangled devices (i think the first was a SoundBlaster 8-bit adapter) would do), many many applications default to this, and for compatibility reasons its being fudged in the Windows driver SW rather than aborting the requesting application. Funny enough (or not as things may be) Linux drivers don't do this and abort any application requesting 11.025 from one of these devices! (this is the only case I know of where resampling comes into play). Anyway, if your purpose isn't high quality HiFi or ultra high sampling rate for SDR radios, i can recommend the cheaps sound cards - get real, they have more than sufficient dynamic range, and you only need a frequency response of some 500-2500 Hz anyway! Vy 73 de OZ1PIF/5Q2M, Peter * ** Genius is one per cent inspiration, ** ** and ninety-nine per cent** ** perspiration. ** ** -- Thomas A. Edison ** * email: peter(no-spam filler)@frenning.dk http://www.frenning.dk/oz1pif.htm Ph. +45 4619 3239 Snailmail: Peter Frenning Ternevej 23 DK-4130 Viby Sj. Denmark *
