locked Re: Second sound card recommendaiton


Joe Subich, W4TV
 

Some very extensive tests were run with Direwolf software looking at
decoding efficiency vs. Soundcard quality. At that time they provided
test files, so you could verify the results yourself.
Direwolf is an AX.25 package. It did not perform any testing with
standard RTTY, or any of the "Joe Taylor modes". I can assure you
that I can copy many more stations with a good high reference 24 bit
ADC and low internal noise receiver than I can with the same receiver
and a "commodity" 16 bit ADC like those found in the common USB dongle,
SignaLink or even the internal 16-bit USB CODEC/ADC in many of the
current transceivers.

73,

... Joe, W4TV


On 2021-10-23 8:17 PM, Hasan Schiers N0AN wrote:
Hi Joe,
Some very extensive tests were run with Direwolf software looking at decoding efficiency vs. Soundcard quality. At that time they provided test files, so you could verify the results yourself.
They could find no improvement in decode efficiency with higher end sound cards vs. a 5 dollar USB dongle (1200 baud packet)
The testers concluded there was little or nothing to gain spending the extra money, as it did not produce enhanced results.
That was quite a few years ago, maybe things have changed, but I doubt it.
73, N0AN
On Sat, Oct 23, 2021, 2:08 PM Joe Subich, W4TV <lists@subich.com <mailto:lists@subich.com>> wrote:
On 2021-10-23 1:44 PM, Hasan Schiers N0AN wrote:
 > There is no advantage to spending a bunch of money for a fancy sound
 > card for the digital modes. They don't need it, and you gain
nothing.
This is only true when speaking about 16bit CODECs running off a 3.3
or 5V supply.  If the sound card has a 24 bit ADC with a higher
voltage reference you can obtain several dB more dynamic range if
the receiver and sound card preamp are well designed (low noise).
This does rule out most of the JA rigs and commodity sound cards but
saying the 24 bit sound cards are of no value is certainly an over-
simplification.
73,
    ... Joe, W4TV

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