----- Original Message -----
From: "Martin, AA6E" <martin.ewing@gmail.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, April 25, 2005 00:18
Subject: Re: [TenTec] cw creation
> In theory, there really is no difference. The math is equivalent and
> there's no way you can distinguish a CW signal that starts life as a
> keyed AF tone and gets mixed up to RF and one that starts as "RF" or
> some intermediate frequency oscillator.
You mean the spectra of the output signals is identical, including sidebands
?
>
> In practice, it may be a different story. Your code practice
> oscillator and AF chain can be noisy and distorted, even if there are
> no dogs barking or phones ringing. The DSP rigs probably generate the
> waveform mathematically and noiselessly -- except for sampling and
> quantization issues. (Some filtering is required to purify the output
> of any digital-to-analog converter, and that might add some extra
> "personality".) I'd expect them to be pretty close to ideal -- and a
> lot better than some non-digital rigs you can still hear on the air.
>
> 73, Martin AA6E
>
> On 4/24/05, Bob Stephens <bstephens1@mindspring.com> wrote:
> ...
> > 5. I still don't really understand what J2A audio type keying is. What
is
> > the difference between J2A and simply keying the rig in SSB mode while
> > holding the microphone to the output of a code practice oscillator?
> >
> > It is possible that I'm totally clueless <grin> ... and so I ask
questions ;-)
> >
> > tnx & 73
> > Bob, KB1CIW
> >
>
> --
> martin.ewing@gmail.com
> http://blog.aa6e.net
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>
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