[Elecraft] K3 and USB Audio Codec

[Dr. Werner Furlan]

hi Joe, 

I am a bit late for a reply, but anyway. 
The way the codec is implemented is (as far I understand it) different and 
more straitforward. There is no "soundcard" in the radio, but the data 
stream is directly derived from the IF-DSP.
My friend Gert, OE3ZK described it as follows:

Es wird kein eigener (billig) SoundChip eingesetzt. Die USB Audio CODEC 
Aufbereitung erfolgt direkt aus der ZF-DSP der Transceiver. Abgesehen von 
den Quarzungenauigkeiten der billig Sound-Chips wird  DSP nicht 
kaskadiert, das ist der wesentliche Qualitätsunterschied.

I translate: 
There is no (cheap) Soundchip in the radio. The USB Audio Codec is 
directly created out of the IF-DSP of the transceiver. There are no 
inaccuracies of the cheap soundchip quartz and there is no cascading of 
DSP's, that is a significant difference in quality.

I have a block diagram of the IC-7200 on my website, you can see it here:
http://oe9fwv.shacknet.nu/oe9fwv/bilder/IC-7200%20USB.jpg

This is an interesting approach in my opinion and has two major 
advantages. Better quality of the signal for soundcard modes independent 
from external soundcards, no additional cables and devices for mobile use. 
A radio and the computer.
Thats all. Remote control included.

73! de Werner OE9FWV


Joe Subich, W4TV-4 [via Elecraft] schrieb am 13 Jul 2010 um 9:17:

> 
> 
> > I don't trust the quality of an external soundcard of this price. 
> > It might be sufficient for PSK31 but probably not for Winmor. The 
> > Signalink USB is good, but not for 20 bucks. 
> 
> The USB Audio CODEC integrated circuit in the IC-7000 or IC-7600 has 
> the same specifications as the USB Audio CODEC in Signalink or a $15 
> USB headset adapter. There is no benefit to putting audio to digital 
> conversion in the radio and bringing the audio out using a driver 
> dependent protocol. 
> 
> An integrated "USB audio CODEC" is nothing more than a gimmick that 
> provides no performance benefit while limiting user flexibility/choice,
> increasing cost and decreasing reliability. 
> 
> If one were going to provide digital output, it would be far better 
> to stream the raw in I/Q data from the DSP's ADC via firewire rather 
> than push it through two additional A/D and D/A steps and reduce it 
> to a single channel of audio. 
> 
> 73, 
> 
>   ... Joe, W4TV 
> 
> 
> On 7/10/2010 3:48 PM, oe9fwv wrote: 
> 
> >
> > I don't trust the quality of an external soundcard of this price. It 
> might be 
> > sufficient for PSK31 but probably not for Winmor. The Signalink USB is 
> good, 
> > but not for 20 bucks. 
> > I have not heard of a problem with the DSP in the IC-7200 or 7600. 
> >> From what I have heard this is not a real soundcard but the IF passband 
> > after the DSP is sent to the audio codec via USB. 
> > It would make it very easy using the K3 for digital soundcard modes 
> without 
> > another external device. 
> >
> > 73! de Werner OE9FWV 

-- 
There is so much sand in Northern Africa, that if we spread it out, it 
would completely cover the Sahara Desert.


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