View Full Version : Computer Sound Card
N7TML
09-04-2007, 01:14 PM
I'm interested in trying out some of the digital modes. Does a computer sound card have to be something specifically for ham radio applications or is it just a sound card that comes with a computer?
Tom
N7TML
K3WRV
09-04-2007, 01:34 PM
It's just a regular sound card, BUT:
Some "sound cards" are better than others. I've got a Gateway P-4 hr, and the onboard sound card is incredibly noisy (SSTV pics, even from strong stations are very snowy. A cheap genuine Soundblaster™ solved the problem). Also, for SSTV, many of the soundcards that come with the newer computers have some pretty severe timing problems. But you'll have to adjust the slant with any card, and you can overcome the timing issues with adjustment.
So wath out for on board sound cards. They may work, or not.
de Bob
It depends on what you want to do with the sound card.
If it's for digimodes (or SSTV), then most cards that can do 48kHz are fine.
If it's for software defined radio, then you need something at least 96kHz and low noise. Some cards (such as the SB audigy) also have timing issues which you'll have to compensate for in software.
It is not necessary to have a 24/96 soundcard for a software defined radio, unless you are talking a really high-end machine. I am playing around with two pieces of software in conjunction with a Softrock™ SDR qrp rig, and both are very happy with 48ksps.
The programs btw, are "Rocky"™ and "PowerSDR" which IS designed for a much more expensive radio, but does have plugins for the Softrock series of rigs. The software is quite impressive, btw, and just using audio from the output of my old Icom 720a, I was able to easily decode some CW in the software DSP that I could hardly even hear coming from the Icom speaker. I can't wait to get the little receiver finished!
73, Jim
Quote[/b] (AG3Y @ Sep. 04 2007,10:44)]It is not necessary to have a 24/96 soundcard for a software defined radio, unless you are talking a really high-end machine. I am playing around with two pieces of software in conjunction with a Softrock™ SDR qrp rig, and both are very happy with 48ksps.
The programs btw, are "Rocky"™ and "PowerSDR" which IS designed for a much more expensive radio, but does have plugins for the Softrock series of rigs. The software is quite impressive, btw, and just using audio from the output of my old Icom 720a, I was able to easily decode some CW in the software DSP that I could hardly even hear coming from the Icom speaker. I can't wait to get the little receiver finished!
73, Jim
I agree that you do not need a 24/96 sound card for SDR.
However, it's much better to use a 96kHz card with SDR, if not 192kHz.
Many of the cheaper sound cards have a high noise floor and poor filtering, which will give you a noise "spike" around the center.
As for high end machine - I disagree. My 6 year old Dell Pentium 4 2.0GHz is doing just fine with a 96kHz card. At 192k it chokes though.
KB2FCV
09-04-2007, 06:55 PM
Most any sound card will work if you plan on using digital modes using your soundcard with most of todays conventional rigs. If you plan on dabbling in SDR, then I would reccommend finding something with at least 96khz sampling rate and STEREO INPUTS. There's lots of information on SDR in the softrock40 yahoo groups. For most of the digital mode stuff i do, I use an 8 or 9 year old pentium 1 laptop running digipan, hellschreiber or whatever other digital mode software I can think of. My P4 plays with SDR.
M3URZ
10-16-2007, 11:50 PM
windows and the graphics card does the damage. switch off all windows services and programs not needed. A very difficult but possible task.Then put your graphics card into classic vga. sit back and enjoy. a 66mz 486 will work if the program would support it.
K7EIQ
11-11-2007, 09:29 PM
To make life simple get a Signalink USB (has built in sound card) and then you will not have to use your computer's card at all..Signalink USB is sold by Tigertronics (the manufacter) based in Oregon. see reviews of the unit in eHAM.net..good luck
