[CW] Good Sounding Sidetone or Code Practice Oscillator Kit

[D.J.J. Ring, Jr.]

Wym, code practice oscillators are very hard to find these days, and I do
not find it a bad thing for people to sell them, I find it a very good
thing.

I did find some schematics, and I posted the locations on this list, but I
tried to find my post and I can't find it.  One was from a fellow in the
Phillipines, and that was an excellent circuit.  One of the list members
made one of those up for me and I use it daily to send a little Morse to
myself while I eat breakfast.  :-)

Almost everything is on the Internet and unfortunately sometimes it is
really difficult to find.  So bookmarks are needed and I keep on loosing my
bookmarks!

We aren't set up for files on this list but we can send links, if anyone
has found anything CW related, we are always willing to read about it.

73

David N1EA

On Tue, Aug 13, 2013 at 3:59 PM, pa0wv <pa0wv at amsat.org> wrote:

>
>
> Dave,
>
> I have nothing for sale. hi
>
> I just read the story on the website of the announced (by you) kit seller,
> I noticed a number of bloops, and I reacted on that. Nothing else.
>
> Furthermore I published the spectrum of the signal of the distributed wav
> file of the kitseller and of the demosignal that I provided with the same
> leading and trailing edge; slope cosine squared.
>
> When you increase pitch, that has nothing to do with the slope of 18 ms
> (mS means millisiemens, what you probably call millimho) the right way to
> write millisecond  by international agreed standards is ms)
>
> The carrier (here: pitch of the audio) has nothing to do with the
> bandwidth of the signal. When you make your signal at a higher pitch with
> the same slope the spectrum is shifted upwards in audio frequency but the
> bandwidth keeps being  the same. And so 33 wpm is still the max speed even
> at 1200 Hz carrier pitch, because the leading and trailing edge of each 18
> ms meet each other in that case  with that speed in wpm.
>
>
> The number of sinewaves of the carrier in a dit is not of influence on the
> bandwidth of the spectrum. The slope (leading and trailing edge) and the
> construction of the slope is important.
>
>
> I forgot to mention the point that the logarithmic sensitivity of the ear
> has in my humble opinion nothing to do with the slope construction of 7
> times 3 dB increments, as the kitseller posted on his website, because just
> as with AGC the ear has to be slower in regulating the sensitivity then the
> envelope of any signal you detect with the ear, otherwise you should
> compress the audio signal amplitude variations.
>
> When the kitseller thinks that a phasejump should have any negative
> influence  at the start of his dit, he has to accept a phasejump at the
> stop of the dit, unless the speed is such that an integer number of half
> waves of the pich (carrier) is just equal in time to the length of one dit.
>
> When he uses 1% resistors and the smallest is 1 % larger then nominal and
> all the other 7 resistors are 1% smaller then nominal it is easy to see
> that a step of value 127 to 128 (01111111 to 10000000 binary) yields a
> spike of 4% of the sinewave amplitude.
>
> The spectrum (= Fourier transform) of the demo18ms.wav that I provided and
> the signal the kitseller provided are available on my website as announced
> in a previous posting.
>
>
> 73 Wim PA0WV
>
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