[WriteLog] Sound card interfaces?

[Joe Subich, W4TV]

 > Looked at the specs on West Mountain and MicroHam—especially the USB
 > interface III (it looks like it needs the CI-V which I do not have).

USB interface III includes the CI-V (CT-17) capability.

 > I have been using the Signalink for a couple of years with my 7800
 > and running AFSK.

I would recommend a dual channel capable interface with the 7800.
While you may not use it now, there will come the day that you want
to do at least split RTTY and have the ability to "listen in the
pile" to track where the DX is working.  Without a dual channel
capable interface (e.g., DigiKeyer II) and software capable of decoding
both receivers, you will be at a disadvantage.

 > It looks like the MicroHam devices  may be a superior sound chip to
 > the SignaLink and others?

It's not so much the sound chip - the majority of USB sound devices
use a 16 bit CODEC all of which have the same theoretical dynamic
range - it is the implementation (circuit) that makes a difference.
Some designers (and I will not say which <G>) fail to provide enough
filtering and decoupling on the USB power line and leave out the
voltage regulators (or use regulators with poor noise performance)
for the CODEC reference voltage and op-amp V/2 ("virtual ground").

Without the regulated reference voltages and improper noise filtering
on the USB +5V power, the "low quality" devices have a significantly
higher noise floor and often show spurious signals/hum in the audio
passband.

73,

    ... Joe, W4TV


On 2/15/2017 2:38 PM, W5XB wrote:
> Hi Diddlers,
>
> I have been using the Signalink for a couple of years with my 7800
> and running AFSK.
>
> Looked at the specs on West Mountain and MicroHam—especially the USB
> interface III (it looks like it needs the CI-V which I do not have).
>
> In the past,  several have suggested the sound card chip itself is a
> major factor in copying weak signals, as well as the filtering of the
> USB power.
>
> It looks like the MicroHam devices  may be a superior sound chip to
> the SignaLink and others?
>
> I only run SO1R....and I don’t need lots of “fancy features.”
>
> I noticed during the WPX, I have some problems copying weaker
> stations and would like to try to improve that.
>
> I don’t know if Joe, W4TV monitors this list, but I am happy to hear
> ALL suggestions.
>
> What do you all recommend?
>
> Thanks and 73s, Grant, W5XB
>
> w5xb <at> att.net _______________________________________________
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