[TenTec] cw creation

[Steve Baron - KB3MM]

----- Original Message ----- 
From: "Martin, AA6E" <martin.ewing at gmail.com>
To: "Discussion of Ten-Tec Equipment" <tentec at 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 at 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 at gmail.com
> http://blog.aa6e.net
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>