[amsat-bb] Re: Measuring the ADC output of a sound card

[Nate Duehr]

On Jul 28, 2007, at 7:03 PM, Alan P. Biddle wrote:

> Simon,
>
> What brought this question about is a test with a new soundcard, a  
> SignaLink
> USB.  It have noticed that it is somewhat less sensitive than some  
> previous
> cards I have used, which readily saturated unless I reduced the signal
> input.  The SignaLink USB does not saturate, even at full gain, in  
> the same
> application, which raises the question of whether I have enough  
> signal.
> There are some issues which can be in the programs and CODECS,  
> which is why
> I was wondering about something which gives you the raw ADC data.

You actually got one?  My two have been on order since April, and  
nothing but a postcard saying they were "having trouble getting their  
aluminum boxes" from their supplier.

I don't think that's the whole story -- hundreds of places will make  
custom aluminum.

If you just received that unit, perhaps you (and others) should  
compare the guts of an older one with a newer one.  Especially if  
other reports of odd level issues start to show up.

If you have had it a while, disregard...

--
Nate Duehr, WY0X
nate at natetech.com