Date: Tue, 18 Jun 2019 20:43:11 +0000 (UTC)
From: Markus Vester <markusvester@aol.com>
To: rsgb_lf_group@blacksheep.org
Message-ID: <1661234464.2572111.1560890591920@mail.yahoo.com>
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Subject: Re: SLF: Sidebands arround ZEVS in 1 mHz
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Hi Stefan,
it seems these sidelines are about 10 dB down at +- 6 mHz. If they were rea=
l, we'd surely see them in 424 uHz at DL0AO, but there's nothing there.
What is strange ist that the main carrier is shown 2 mHz below the 82 Hz ti=
ck, wheras in reality ZEVS is only 10 uHz below nominal. So I suspect that =
the real input samplerate is around 24 ppm higher than what SpecLab thinks =
it is. This=C2=A0may cause periodic buffer overflows, where samples are los=
t and phasejumps occurs.=C2=A0The sideline spacing indicates that this is h=
appening every 1000/6 seconds (~ 3 minutes).=C2=A0

73, Markus

-----Urspr=C3=BCngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group@blacksheep.org <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 18. Jun. 2019 17:53
Betreff: SLF: Sidebands arround ZEVS in 1 mHz

These days i'm calibrating the colours and angles in my ELF...VLF=20
spectrograms. The colour of ZEVS is now calibrated to deviate less than=20
3 deg. However producing a spectrogram in 1 mHZ FFT bin width, i can see=20
sidebands of ZEVS.
Did someone else observe a similar effect?
In a first thought i would assume it is my timing system that causes the=20
problem. But maybe it is ZEVS itselfe? Or even propagation?

73, Stefan

PS: Capture attached.


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<div style=3D"font-size:10pt;font-family:arial,helvetica,sans-serif;color:b=
lack;"><div style=3D"font-family: arial,helvetica,sans-serif; font-size: 10=
pt; color: black;" data-mce-style=3D"font-family: arial,helvetica,sans-seri=
f; font-size: 10pt; color: black;">Hi Stefan,</div><div style=3D"font-famil=
y: arial,helvetica,sans-serif; font-size: 10pt; color: black;" data-mce-sty=
le=3D"font-family: arial,helvetica,sans-serif; font-size: 10pt; color: blac=
k;"><br></div><div style=3D"font-family: arial,helvetica,sans-serif; font-s=
ize: 10pt; color: black;" data-mce-style=3D"font-family: arial,helvetica,sa=
ns-serif; font-size: 10pt; color: black;">it seems these sidelines are abou=
t 10 dB down at +- 6 mHz. If they were real, we'd surely see them in 424 uH=
z at DL0AO, but there's nothing there.</div><div style=3D"font-family: aria=
l,helvetica,sans-serif; font-size: 10pt; color: black;" data-mce-style=3D"f=
ont-family: arial,helvetica,sans-serif; font-size: 10pt; color: black;"><br=
></div><div style=3D"font-family: arial,helvetica,sans-serif; font-size: 10=
pt; color: black;" data-mce-style=3D"font-family: arial,helvetica,sans-seri=
f; font-size: 10pt; color: black;">What is strange ist that the main carrie=
r is shown 2 mHz below the 82 Hz tick, wheras in reality ZEVS is only 10 uH=
z below nominal. So I suspect that the real input samplerate is around 24 p=
pm higher than what SpecLab thinks it is. This&nbsp;may cause periodic buff=
er overflows, where samples are lost and phasejumps occurs.&nbsp;The sideli=
ne spacing indicates that this is happening every 1000/6 seconds (~ 3 minut=
es).&nbsp;<br><br>73, Markus<br><br>-----Urspr=C3=BCngliche Mitteilung-----=
<br>Von: DK7FC &lt;selberdenken@posteo.de&gt;<br>An: rsgb_lf_group@blackshe=
ep.org &lt;rsgb_lf_group@blacksheep.org&gt;<br>Verschickt: Di, 18. Jun. 201=
9 17:53<br>Betreff: SLF: Sidebands arround ZEVS in 1 mHz<br><br></div><div =
dir=3D"ltr">These days i'm calibrating the colours and angles in my ELF...V=
LF <br></div><div dir=3D"ltr">spectrograms. The colour of ZEVS is now calib=
rated to deviate less than <br></div><div dir=3D"ltr">3 deg. However produc=
ing a spectrogram in 1 mHZ FFT bin width, i can see <br></div><div dir=3D"l=
tr">sidebands of ZEVS.<br></div><div dir=3D"ltr">Did someone else observe a=
 similar effect?<br></div><div dir=3D"ltr">In a first thought i would assum=
e it is my timing system that causes the <br></div><div dir=3D"ltr">problem=
. But maybe it is ZEVS itselfe? Or even propagation?<br></div><div dir=3D"l=
tr"><br></div><div dir=3D"ltr">73, Stefan<br></div><div dir=3D"ltr"><br></d=
iv><div dir=3D"ltr">PS: Capture attached.<br></div>
<br></div>
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