In order to get a better understanding of transatlantic propagation on
136kHz it would be interesting to record the Canadian Naval station CFH (on
137kHz) on a number of (European) locations during the same period.
As far as I am informed CFH will be recorded in the UK, Sweden and Belgium,
but it would be usefull to have some more participants from other countries
too.
CFH is transmitting a continious carrier for the last days, this makes
recording easier so I suggest to have a first recording period during the
night of monday 18 december (starting 18UTC) / tuesday 19 december (until
CFH fades away, or you have to leave for work).
For those who have no special recording equipement it is possible to make a
recording using the PC soundcard and the 'eclipse' software that can be
downloaded from :
http://hamradio.nikhef.nl/tech/prog/eclipse.htm
The ZIP file includes the program and a manual. The 2 main things you have
to keep in mind with the eclipse software is :
1. The receiver AGC should NOT become active during recording, there are 3
options to ensure this :
- set AGC off if your RX allows this
- add sufficient attenuation between antenna and RX
- set the 'RF gain' to a sufficient level to ensure that it will not be
'overruled' by the AGC.
2. The soundcard should not be saturated during the recording. Ensure that
the audio gain control is not too high (the 's-meter' of the eclipse
software should be at -40dB or less when CFH is absent).
If possible check the values for attenuation (or RF gain) and audio gain
during one of the noghts prior to monday to ensure that there is no
clipping or saturation.
Data file can be sent to me (please zip), name it yourcall.txt (eg.
ON7YD.TXT),
I will forward the data to Alan (G3NYK) and to whoever is interested.
Those who record 'mechanical' (pen recorders) can either scan the result
and send it as a picture (any format is OK) or just mail it to Alan or me
(whatever is cheapest).
Remind that not only the propagation differences over larger distances are
interesting but also over short distances, it is possible that there can be
remarkable differences even when the recording stations are only a 25km
apart, so everyone can make a meaningfull contribution by participating.
73, Rik ON7YD
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