> No, that is not the "only" way. You can use fldigi in
> normal AFSK mode, and use K4DSP's FSK Regenerator:
That's true. Although the K4DSP FSK Regenerator will run
on any AFSK software (and any soundcard) without the special
p-FSK output, p-fsk is the only "supported" method for
generating "true" FSK in fldigi.
In addition, the envelope detector/switch approach works
with audio generating only CW software to allow it to
work properly with a real CW receiver.
73,
... Joe, W4TV
> -----Original Message-----
> From: Kok Chen [mailto:chen@mac.com]
> Sent: Sunday, August 16, 2009 4:28 PM
> To: RTTY Reflector
> Cc: W4TV Joe Subich
> Subject: Re: [RTTY] Advise requested for RTTY Hardware
>
>
>
> On Aug 16, 2009, at 11:37 AM, Joe Subich, W4TV wrote:
>
> > The only way to do FSK (as opposed to AFSK) with fldigi is using an
> > envelope detector/driver as is done in USB Interface III (or as
> > documented in the fldigi help files).
>
>
> No, that is not the "only" way. You can use fldigi in normal AFSK
> mode, and use K4DSP's FSK Regenerator:
>
> http://k4dsp.homeip.net/~doug/regenerator/
>
> It is however, not an appliance operator's box. Some assembly and
> competency with a soldering iron is required (or use a solderless
> breadboard, as I had done when I was testing it :-).
>
> You can indeed use Doug's regenerator with any AFSK software on any
> operating system. *Anything* that puts out an AFSK tone pair,
> including all the old TNCs (in AFSK mode) will work. With Doug's
> regenerator, there is no need for a special 1 kHz secondary keyed
> tone. Just use the standard 2125/2295 AFSK tone pair on a single
> audio channel.
>
> Simple as it is, the AVR firmware in Doug's circuit is not just an
> envelope detector, but the firmware includes a full fledged AFSK
> demodulator. It does require a signal with good SNR, but a computer
> sound card output is more than clean enough for it. It demodulates
> and slices the AFSK signal into an FSK signal (and while doing that,
> it also generates PTT). It will also generate an independent CW
> keying signal for various Windows and Mac OS software that generates
> CW for J2A modulation by the rig.
>
> 73,
> Chen, W7AY
>
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