[Elecraft] Need local help

[Joe Subich, W4TV]

> I think there is one point that is overlooked in a lot of these
> discussions. It really doesn't take much of a sound card to do
> digital signal processing on 3 KHz or less audio streram.

There are a significant number of reports concerning the issues with
Signalink on-line if one bothers to look.  In general they relate to
improper filtering of the USB +5V power, lack of a regulator for the
V/2 reference to the sound codec (analog to digital converter), lack
of proper bypassing of noise from the various chips, requirement that
the digital to analog converter be run at too high a level in order
for the "VOX" to trigger reliably, etc.

In general, this means Signalink loses 15 dB or more of signal to
noise ratio (which is a big deal with modes like JT65 and JT9 on HF)
on the receive side and is much more "dirty" (often with multiple
audio signals) on transmit.

You're correct that it does not take much of a sound card to decode
some signals.  However, the Signalink "sound card" contains most of
the same components as the generic USB sound products that perform
much better - yet Signalink costs two to three times as much.

73,

    ... Joe, W4TV


On 2015-06-09 3:59 PM, Barry LaZar wrote:
> Joe,
>      You bring an interesting point of view. I've been using a SignaLink
> USB for at least 3-4 years. I haven't had an issue with it except not
> enough time to play. And, I can't blame the manufacturer for that.
>
>      I think there is one point that is overlooked in a lot of these
> discussions. It really doesn't take much of a sound card to do digital
> signal processing on 3 KHz or less audio streram. However, I would never
> use a card in my laptop or my I/F for some of the heavier lifting here
> in my shack where I need 96KHz sample rates or better with 24 bit
> digitizing. But for just hook it up, set the levels and go, an interface
> with a built in sound card is not a bad way to go. In many cases, it is
> just easier to do and it allows for more flexibility.
>
> 73,
> Barry
> K3NDM
>
> On 6/9/2015 3:11 PM, Joe Subich, W4TV wrote:
>>
>> On 2015-06-09 12:02 PM, Bob N3MNT wrote:
>>> OP said computer did not have an audio input.
>>
>> He's still better off with an external USB sound card of reasonable
>> quality and a pair of audio cables than using the Tigertronix product
>> of dubious quality and well documented poor design.  A simple USB sound
>> card of reasonable quality will cost 1/3 to 1/2 as much as the inferior
>> "amateur" product.
>>
>> 73,
>>
>>    ... Joe, W4TV
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