500kHz WSPR reception at M0BMU

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M0BMU
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Joined: 2008/12/17 - 13:34
500kHz WSPR reception at M0BMU

Dear LF Group,

I have been running a dedicated WSPR receiver and PC more or less full time for the past few weeks on 502.4kHz "dial frequency" (other LF/MF frequencies possible if requested), with loggings uploaded to the WSPRnet database. It is good to see there have recently been a few new countries QRV in 500kHz WSPR mode, including EI6IZ, LA3EQ/P and PA3FNY.

Some info for stations looking at their spots in the database - The 500kHz receive antenna here is currently a phased vertical/loop combination which is necessary to reject local QRM. It produces a single deep null on a bearing of about 90degrees from here. The directional pattern only makes a few dB difference to signals from most directions, but obviously signals coming from the east , e.g. from ON, PA, DL, are heavily attenuated and will show low values of SNR as a result. An omnidirectional antenna would be preferable from the propagation study point of view, but unfortunately the noise level would be increased by at least 20dB, and many of the weaker signals would then be undetectable. So this seems the best option at the moment. The WSPR receiver is an RA1792 with an old 400MHz laptop.

Cheers, Jim Moritz
73 de M0BMU