[Elecraft] [OT] PCI Express sound card for digimodes

[N2TK, Tony]

Tnx Chen, but I am running Microsoft.

N2TK, Tony

-----Original Message-----
From: Kok Chen [mailto:chen at mac.com] 
Sent: Saturday, January 30, 2010 2:37 PM
To: Elecraft Reflector
Cc: N2TK, Tony
Subject: Re: [Elecraft] [OT] PCI Express sound card for digimodes


On Jan 30, 2010, at 9:57 AM, N2TK, Tony wrote:

> Does anyone make a sound card, internal or external that has two separate
> inputs/outputs?

I believe stereo sound cards are actually more common than mono sound cards.
Edirol (I think) makes an inexpensive mono USB sound card, but almost
everything else out there are multi-channel (both the E-MU 0404 (USB) and
Edirol FA-66 (FireWire) have 4 channels, for example). 

However, some ham digital interfaces that include sound cards don't wire the
right stereo channel, even though the chipsets in them are stereo; examples
are the SignaLink USB and the microHAM USB Interface III. But many of the
digital interfaces that come with sound cards do support two channel
receive.  Some, like the microHAM digiKeyer and microKeyer II even have a
pair of front panel pots to ride the gain for each channel independently.

The next issue is whether the software that you use allows you to select
either the left or the right channel, even if the sound card has that
capability.

> Right now I am using two sound cards for RTTY with my K3 -
> one for the main receiver and one for the sub-receiver. This way, when I
> turn on the sub-receiver I can tune around the band and decode the RTTY
with
> the sub-receiver while I am decoding the RTTY on the main receiver. I am
> using two MMTTY programs at the same time.

With cocoaModem (a Mac OS X program), you won't need to run two copies to
print from two receivers.  The principal RTTY interface in cocoaModem
already has two independent channels (two waterfalls, two cross ellipse
indicators, independent tone pairs, etc) within the same window (no window
focus problems :-). See Fig. 11 here:

http://homepage.mac.com/chen/w7ay/cocoaModem/UsersManual/RTTYPage/WidebandRT
TY/WidebandRTTY.html

A button on the bottom left selects if you want to transmit on the audio
tone pair of the main receiver or the sub receiver. 

The two RTTY channels in that program can be set to take signals from two
different sound cards, or different channels from the same sound card (the
way I use it on a microKeyer II), or even the same channel on the same sound
card (so you can use slightly different demodulation parameters on the same
signal).   No, it doesn't have diversity RTTY yet, but it will come one day
:-).

73
Chen, W7AY