How to setup the Receiver and the Software
Joachim Köppen DF3GJ Kiel/Strasbourg/Illkirch Summer 2004
When the receiving station is first set up, check whether the use of the
narrow band filter is needed: Listen to the audio output for any signs
of music or speech transmission which are present irrespective of the
setting of the tuning control (right hand knob). But you must check at
several times of the day, and for a couple of days, because the ionospheric
conditions - which cause strong short wave broadcast signals - change
If you need to use the filter, you should convince yourself that the filter
is optimally tuned (it might have changed due to the transport!):
- turn on the calibrator, use maximum noise, and switch from antenna
to calibrator. Set the receiver tuning control in the 12 o'clock
position, i.e. in the centre of the tuning range.
Listen to the audio output and observe the tracing on the SkyPipe chart
- slowly and gently turn the screws of the trimmer capacitors in either
way, until you get a maximum noise output. Note that the trimmers
come in two pairs acting in parallel. Use the one whose screw is sticking
more our than the other.
- Change the receiver tuning to both ends of the range. The noise level
should fall off somewhat towards the ends, preferably in the same
amount to either side. If this is so, the filter's pass band is centered
on the middle of the receiver's tuning range
- If not, adjust the trimmers a bit more, until you get an almost
symmetrical fall-off of the noise.
- The filter tuning might change due to mechanical handling and strong
temperature changes. After placing in position at the receiving station,
it may need a bit of time to relax. This means that in the first few days
the filter's passband might drift a little off the frequency of the receiver,
and thus the receiver will get less signal...
- To check this, we simply use the receiver I sent from Strasbourg,
operating it for the first few daya, and making regular calibrations.
If one notices that the audio amplitudes for the various calibration
steps change systematically and significantly (say, by more than 3 to
5 percent), we have to retune the filter a bit.
- But once settled and tuned properly, the filter remains stable over
months! This is our experience at ISU
The Radio-SkyPipe software has to be configured to suit your needs
Help pages are here): In the Options menu
- submenu Identity enter the details of your station and
set the correct time zone
- submenu Stripchart: set data sampling and averaging rate.
At ISU we now use:
Also, you can influence how the plot is being done (setting the
your default value for the maximum ordinate, and the number of ticks
on the axes, the colour of the tracing, etc)
- sample period (stand alone): 20 ms (default value is 10 ms)
- averaging (stand alone): over 20 samples (default value is over 5
- I found our present setting more suitable than the default one; we do
not loose significantly in the data, but one can store about 7 hours
in a file with 50000 data points. The data volume is about 3 MB/day
(and 100 MB per month), whereas it would be 30 MB/day with default
- submenu Logging: specifiy that you want to use UT,
give maximum duration or maximum file size (I use 50000 samples which
gives files of about 800 kB size), and whether you want to restart the
chart at a specific time (I use 00:00 UT).
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