Dear VLF,
Attached you find the results of Paul Nicholson of my 8th VLF
experiment. Interesting links and he seems to confirm that my frequency
is pretty accurate now ;-)
Furthermore the first part gives an idea of future planned VLF tests i
hope to do on my earth antenna :-)
73, enjoy,
Stefan7DK7FC
-------- Original-Nachricht --------
Hi Stefan, et al
My report of your test on Saturday is below.
> What do you think about a test on the earth antenna,
> this week?
We should have a good think about what tests would be
useful to do. For example, to measure the propagation
delay using a chirped transmission (this would move us
a step closer towards the goal of putting a signal
through a whistler duct). I am probably too far away
to take part in such a test.
First transmission 2010-10-23_08:03, 3600 seconds
-------------------------------------------------
Background @ 8970: http://abelian.org/vlf/ss101023/noise8970.png
Before sferic blanking: http://abelian.org/vlf/ss101023/tx1a.png
After sferic blanking: http://abelian.org/vlf/ss101023/tx1b.png
Average frequency: 8969.974924 Hz +/- 1uHz
Absolute phase, measured in 5 minute blocks over 50 minutes:
-151.049
-137.833
-143.681
-113.856
-112.387
-131.829
-117.567
-133.994
-137.574
-119.973
Suggests the transmitter phase is switching between 2 values,
about 20 degrees apart. Spectrum shows some weak sidebands.
Second transmission 2010-10-23_10:33, 1680 seconds
--------------------------------------------------
Background @ 6470: http://abelian.org/vlf/ss101023/noise6470.png
Before sferic blanking: http://abelian.org/vlf/ss101023/tx2a.png
After sferic blanking: http://abelian.org/vlf/ss101023/tx2b.png
Average frequency: 6469.974916 Hz +/-1uHz
Absolute phase, measured in 5 minute blocks over 25 minutes:
-141.539
-153.483
-150.903
-155.623
-157.098
Third transmission 2010-10-23_13:21, 2220 seconds
-------------------------------------------------
Background @ 5170: http://abelian.org/vlf/ss101023/noise5170.png
Before sferic blanking: http://abelian.org/vlf/ss101023/tx3a.png
After sferic blanking: http://abelian.org/vlf/ss101023/tx3b.png
Average frequency: 5169.999969 Hz +/-1uHz
Notes
-----
The spike in the 8970Hz noise chart at 16:05 is the current injection
calibrator and at 16:30 the gain of the E/W loop was adjusted. Vertical
scale refers to the calibration before the gain change.
The average frequencies are all on the low side, by between
6ppb and 12ppb.
--
Paul Nicholson
--
|
|
