So Chen, why isn't cocoaModem available on Windows? I'm especially curious
since Apple computer now run Intel processors and run Windows. I'm sure I'd
love your software but I know I will never own an apple computer (my Ipod
doesn't count).
73, Art W2NRA
"Keep to the Code!"
w2nra.com
----- Original Message -----
From: "Kok Chen" <chen@mac.com>
>
> On Jan 24, 2009, at 10:25 PM, Dave AA6YQ wrote:
>
>> If you're running a soundcard RTTY engine and a hardware modem in
>> parallel -- you can get close by clicking on the waterfall and then
>> fine
>> tune with the XY display, or let the soundcard RTTY engine's AFC
>> lock on the
>> signal and then click a button that QSYs your transceiver to put the
>> hardware modem dead on frequency.
>
> I almost never use narrow filters on RTTY, and only if the nearby
> signals exceed the dynamic range of my codec when I am trying to copy
> a weak signal among them.
>
> For most of my RTTY work, I click on a waterfall, no AFC. I use a
> mouse scroll wheel to fine tune the tone pair if needed, while
> watching a crossed ellipse. cocoaModem mixes the input into a
> baseband I/Q signal for demodulation, so fine tuning is simply a
> matter of changing the frequency of the numerical local oscillator.
>
> S&P inside a pileup with relatively strong signals don't usually
> require fine tuning. You can normally click close enough
> (cocoaModem's waterfall has a resolution of 2.69 Hz per pixel) by just
> clicking.
>
> A second waterfall usually watches the DX from a second receiver. You
> have lots of time to fine tune that signal in, and often that is
> needed because that signal is usually closer to the noise. Except
> during one of the DXpeditions last year where the DX was searching you
> out instead of staying fix -- that was where being able to quickly
> click on the DX had helped.
>
> In cocoaModem, the mouse scroll wheel will fine tune the tone pair of
> either of the two waterfalls that the cursor is hovering over.
>
> 73
> Chen, W7AY
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