Topband: Digital mode spurious issues

[Mike Waters]

I finally got around to installing WSJT-X. I haven't even read the manual,
but it's decoding JT65 (and maybe JT9) signals on 160 and displaying
callsigns just fine. You don't even have to tune the signals in, they just
have to be in the passband. The software does it all for you.

There are many software adjustments, and I don't yet know what they do. It
worked fine without fiddling with anything except the audio level. I also
selected JT9+JT65, assuming that doing so would display signals on either
of those modes.

Plug the rig's speaker into the mic input on your PC's sound card and tune
to 1838.0 USB. If you see hum from a ground loop, then simply isolate the
audio line using an audio transformer from an old 56k modem. (I put a pot
in there too, as I was overdriving the sound card input without it.) Adjust
the volume until you see noise on the WSJT waterfall, and go do something
else while it collects and displays info.

Intermod from overdriven audio can be seen easier of you turn up the volume
so the waterfall is brighter. And it would help a lot if you played with
PSK31 first (perhaps in Fldigi or Digipan), and saw what an overdriven
PSK31 signal on the waterfall looks like.

I saw several callsigns that were not visible at the URL below. All looked
clean to me, but I didn't look or listen all that close.

73, Mike
www.w0btu.com

On Mon, Dec 30, 2013 at 10:48 PM, Mike Waters <mikewate at gmail.com> wrote:

> Maybe not.
>
> I got a private e-mail earlier (which I haven't had time to respond to
> yet) that stated "To see who is QRV on 160M WSPR at any given time, check at
> http://wsprnet.org/drupal/wsprnet/activity
> Scroll down to 160M and the stations are listed (those followed by an R
> are just receiving)."
>
>
> On Mon, Dec 30, 2013 at 9:55 PM, Tom W8JI <w8ji at w8ji.com> wrote:
>
>> Thanks everyone for the suggestions. I'm going to have to install some
>> software to identify some of the signals.
>>
>
>