In fact, you can. The instrument has to be able to capture a signal and show
you the signal's frequency vs. time. This type of plot is called a
"spectrogram" and can be found on instruments called Vector Signal
Analyzers.
The spectrogram is a little bit like the display you see on one of those
PSK-31 programs (e.g. DigiPan?) which scrolls. Therefore, the horizontal
axis is frequency and the vertical axis is time. Using markers, it is an
easy task to measure delta F and delta T. If the plot is a color plot, color
can be used to indicate amplitude.
This is the technique used to look at the transient turn-on behavior in the
first few milliseconds of a PLL powering up, and also is used by law
enforcement to positively ID a specific transmitter by its turn-on
"fingerprint".
> -----Original Message-----
> From: Paul Christensen [mailto:paulc@mediaone.net]
> Sent: Tuesday, 29 January 2002 5:49 PM
> To: Steve Ellington; tentec@contesting.com; Duane A Calvin
> Subject: Re: [TenTec] Fwd: Topband: More About Clix
>
>
> You can't. In fact, I know of no electronic instrument capable of
> reasonably detecting it. Sometimes the ear is the best
> judge. The keyed
> waveform oscilloscope display has no association with frequency shift.
>
> -Paul, W9AC
>
> ----- Original Message -----
> From: "Steve Ellington" <n4lq@iglou.com>
> To: <tentec@contesting.com>; "Duane A Calvin" <ac5aa@juno.com>
> Sent: Tuesday, January 29, 2002 18:12 PM
> Subject: Re: [TenTec] Fwd: Topband: More About Clix
>
>
> > Since you brought it up;
> > Is there any test equipment that would show "microchirp"?
> It's easy to
> hear
> > but how about viewing it on a scope?
> > Steve Ellington
> > N4LQ
> >
> > ----- Original Message -----
> > From: "Duane A Calvin" <ac5aa@juno.com>
> > To: <tentec@contesting.com>
> > Sent: Tuesday, January 29, 2002 12:21 PM
> > Subject: Re: [TenTec] Fwd: Topband: More About Clix
> >
> >
> > > Hmmm.... This doesn't match the ARRL/QST Labs results
> as printed in
> > > their review of the VI+. The keying waveshape was
> textbook perfect. In
> > > monitoring my own signal both in my shack and at a
> friend's QTH about 10
> > > miles away, there are no discernable clicks. (Yes there is the
> > > microchirp, which I consider a minor annoyance.) So, has
> something
> > > changed, or what's the real story?
> > >
> > > 73, Duane
> > >
> > > On Tue, 29 Jan 2002 09:29:45 -0600 Ron Feutz
> <feutz@wctc.net> writes:
> > > > How about this, guys?
> > > >
> > > > I have always been under the impression that my signal
> was clean and
> > > > the
> > > > Yaesu guys were screwing up the bands.
> > > >
> > > > Ron - WA9IRV Omni 6+
> > > >
> > > >
> > > > >To: topband@contesting.com
> > > > >X-Mailer: Juno 5.0.33
> > > > >From: k6se@juno.com
> > > > >Subject: Topband: More About Clix
> > > > >Sender: topband-admin@contesting.com
> > > > >X-BeenThere: topband@contesting.com
> > > > >X-Mailman-Version: 2.0.5
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> > > > >
> <mailto:topband-request@contesting.com?subject=subscribe>
> > > > >List-Id: 160 Meter Information ONLY <topband.contesting.com>
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> > > > >
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> > > > >List-Archive: <http://lists.contesting.com/pipermail/topband/>
To: <tentec@contesting.com>
> > > > >Date: Mon, 28 Jan 2002 14:41:16 -0800
> > > > >
> > > > >Virtually all of today's modern rigs have a key click
> problem. The
> > > > stock
> > > > >FT-1000MP and Mk V CW signal rise time is 2.4 ms and
> the fall time
> > > > is 1.0
> > > > >ms. This is on every dit and dah. The ARRL criteria
> for "clean"
> > > > keying
> > > > >is a rise and fall time of 5.0 ms. After the INRAD keying
> > > > improvment
> > > > >mod, the rise time is 4 ms and the fall time is 2.2 ms. It
> > > > certainly
> > > > >improves the keying, but not enough, which is why I'm
> going to do
> > > > the
> > > > >W8JI key click mod on my MP.
> > > > >
> > > > >A friend has an IC-756 PRO which has clicks extending
> out at least
> > > > +/- 1
> > > > >kHz. Another has a late-model IC-775DSP which has
> clicks as bad or
> > > > worse
> > > > >than the FT-1000MP. Additionally, you can hear a
> "thump" on his
> > > > first
> > > > >dit or dah when he is operating split. Earlier model 775s have
> > > > the
> > > > >additional problem of generating a signal from the receive VFO
> > > > when
> > > > >operating split (becoming worse as the split frequency
> is smaller),
> > > > >clearly an FCC violation. Icom knows about this
> problem because
> > > > they
> > > > >will upgrade the early version if the owner complains, but they
> > > > won't
> > > > >publicly confirm this problem.
> > > > >
> > > > >Many topbanders prefer the Omni VI+ because of its superior QSK
> > > > and
> > > > >excellent receiver. But even it has bad clicks.
> INRAD has thus
> > > > far
> > > > >unsuccessfully tried to develop a mod to correct this. George,
> > > > W2UVG
> > > > >(owner of INRAD) told me, "I have spent many hours
> working on the
> > > > Omni
> > > > >VI+ keying and ALC loop as it has a similar problem.
> The keying
> > > > waveform
> > > > >out of the first mixer is text book perfect, 5 mS up and down.
> > > > Then it
> > > > >goes through the ALC loop and the output has 1 mS rise
> time and 5
> > > > mS fall
> > > > >time. This loop has a very slow decay time, and it
> doesn't change
> > > > the
> > > > >input shape. If I disable the ALC loop the radio puts out 100
> > > > watts and
> > > > >the keying is perfect. But there is no power control, etc."
> > > > >
> > > > >Jim, N7JW has overcome the Omni VI+ click problem by using an
> > > > FT-1000MP
> > > > >with the W8JI key click mod to transmit and an Omni
> VI+ to receive.
> > > > It
> > > > >would be nice if all hams (especially topband
> contesters) were as
> > > > >concerned about having a clean CW signal as N7JW is.
> > > > >
> > > > >I'm not sure how the modern Kenwood radios are as far as clicks
> > > > go.
> > > > >
> > > > >73, de Earl, K6SE
> > > > >_______________________________________________
> > > > >Topband mailing list
> > > > >Topband@contesting.com
> > > > >http://lists.contesting.com/mailman/listinfo/topband
> > > >
> > > >
> > > > _______________________________________________
> > > > TenTec mailing list
> > > > TenTec@contesting.com
> > > > http://lists.contesting.com/mailman/listinfo/tentec
> > > >
> > >
> > >
> > > Duane Calvin, AC5AA
> > > Austin, Texas
> > > _______________________________________________
> > > TenTec mailing list
> > > TenTec@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/tentec
> > >
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
>
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