Re: LF: Cat Whiskers

[M0FMT <m0fmt@yahoo.co.uk>]

OOOK I'll buy that.

 

Lee points out the faint joining lines of constant frequency during period between expansion and contraction of the side bands. Indicating multi-frequency (harmonic) modulation at constant amplitude then ramped to "off" and on "startup" the oppsite happens. OK OK. Some kind of motor control then.

Right..... OK then .............. teach me to ask a silly question!

 

The signal appears pulsed, I guess that accounts for the harmonic modulation content?

 

Thanks for the explanation.
73 es GL petefmt

--- On Fri, 15/1/10, John P-G <gm4slv@sighthound.demon.co.uk> wrote:

From: John P-G <gm4slv@sighthound.demon.co.uk>
Subject: Re: LF: Cat Whiskers
To: rsgb_lf_group@blacksheep.org
Date: Friday, 15 January, 2010, 21:37

On Fri, 15 Jan 2010 13:15:57 -0800 (PST)
M0FMT <m0fmt@yahoo.co.uk> wrote:

> Too glib
>  
> I can visualise the whisker pointing in the direction of time but not
> the mirror image how does that work.

Look like a carrier modulated by a harmonically rich waveform, which
reduces in frequency......


then after a time the carrier is modulated by a harmonically rich
waveform that now increases in frequency......

Not too difficult to imagine?

What's the time scale on the spectrogram?

A motor that slows down, stops and then speeds up?


J