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Hi Joe,
your QRSS signal was visible on my
grabber last night, best between 2:16 and 2:40. As Stefan noted, SNR was
somewhat lower than it used to be, but this may be
due to conditions, or my RX being on the
auxiliary "summer antenna" which is more affected by ADSL noise from buried
telcom cables.
Regarding ultimate stability, the blue trace
still appeared somewhat fuzzy in the top part of the 0.438 mHz grabber
window. Last night, your frequency seemed to be spread between 137777.02 to
137777.04 Hz. Ideally, a perfectly coherent AM modulated
signal should have a narrow and straight central line, with modulation
sidebands spread symmetrically around it like fish bones. So you may still have
a tiny bit of chirp or some phase glitches. Of course this is only relevant
for receiver applications that integrate across several dashes (like the Opera
correlation project), but it will in no way affect the look or readability in
"normal" QRSS spectrograms.
Best 73, and thanks for the signal,
Markus (DF6NM)
Sent: Sunday, June 02, 2013 12:24
AM
Subject: LF: 137.7770
kHz
Dear Group,
QRV again tonight. QRSS30
and seeking comments (especially unfavourable ones) on accuracy, drift and
keying coherence.
Vern's grabber is capturing them well at the
moment. Thanks again, Vern.
73
Joe
VO1NA
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