[Elecraft] [K3] Line out, speakers, and L-mix-R settings...

[Kok Chen]

On Nov 27, 2010, at 11/27    5:14 AM, Joe Subich, W4TV wrote:

> MixW has a dual [RTTY] receive capability - I don't know about any  
> of the other software.

On the Mac OS X side, cocoaModem has two independent receive channels  
in the "wideband RTTY" and the "dual RTTY" interfaces.  There are two  
identical sets of user interfaces in a single window -- this gets rid  
of the "window focus" problem of running multiple copies of a software  
modem.

There are two cross ellipses, independent mark and space tones, baud  
rate, and filter settings -- you can even run 75 baud and Mark-only on  
one decoder, while running 45.45 baud and Mark/Space decoding on the  
other.  In the case of "wideband RTTY," there are independent  
waterfalls.

Dual RTTY decode has been in practice in some time now.  In the old  
days, it was done with multiple TU -- this is one of the reasons why  
normally sane people have multiple HAL ST-8000 in the shack.  Just  
like other modes, having concurrent receive capability on on both the  
DX and a split pile reduces "doubling."

Using multiple TU back then required manually scanning the pileup  
using the VFO knob.  If you have a waterfall that is watching the  
pile, you can pretty much pinpoint the DX's QSX by watching where a  
signal appears in the pileup waterfall right after the DX finishes  
sending his exchange.  A software modem that is capable of agile  
transmit can then pounce on that QSX (or find the next hole in the  
direction the DX is tuning).

It used to be like shooting fish in a barrel for people with two RTTY  
decoders and agile receive (e.g., waterfall tuning) to work the split  
RTTY pileups.  Just ask RTTY DXers who have been using cocoaModem's  
"wideband RTTY" interface.

But more people have that capability today (what with the Flex-5000  
and the LP-PAN), to the point that if you don't have dual decoding and  
agile tuning capability, you are now at a distinct disadvantage.

Of course you need a sound card that has two or more inputs (or a  
digital interface like the microKeyer/digiKeyer).  Some of the cheaper  
digital interfaces are only wired for a single input channel, even  
when the codec is a stereo one.

73
Chen, W7AY