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Last night (Feb 3/4) Joe's TX signal was perfectly
stable again. But not on my grabber - unfortunately my receiver had
been around 20 mHz low and drifting, caused by a loose solder joint
on the BNC plug of the Rubidium injection. Should be fixed
now.
Best 73,
Markus (DF6NM)
Sent: Tuesday, March 03, 2015 10:27 PM
Subject: Re: AW: LF: VO1NA Tue-Wed
Hi Joe & Joe,
these are two separate effects:
The 0.1 Hz sidebands on strong amateur signals
are created by DCF39's telegrams, periodically activating
the noiseblanker every 10 seconds. They may increase
during DCF's "hyperactive" periods, where telegram blocks
are much longer but still adhere to the 10 second pattern. There
are usually four such "bad" periods each day, currently at 3:18 - 3:38, 9:15 -
9:35, 15:18-15:40, and a long one 21:18 - 23:42 UT (give or take a few minutes).
The splatter is so wide because the Burg transmitter is
apparently modulated by an unshaped rectangular FSK waveform (unlike HGA22
which exhibits somewhat softer keying).
The "fuzziness" on Joe's signal is obviously a
real frequency instability of the VO1NA transmitter, which seems to have started
sometime around 23 UT last night. After that, the DCF-induced sidelines simply
became less visible because they were smeared out along with the main
carrier signal.
Best 73,
Markus
Sent: Tuesday, March 03, 2015 8:02 PM
Subject: AW: AW: LF: VO1NA Tue-Wed
Hi
Joe, Markus,
Markus
you´re right, I observed the spectrum during Joe´s fuzzy
phase
DCF39
was splattering over the whole band with extreemly
fieldstrength.
When
I was playing with the sdr-Iq i found, switching off the RF/NB helps a little
and switching on the IF/NR fixed the problem.
Joe,
nice copy again, not so strong as the night b4.
73
Joe
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