18 Aug 2014

472kHz - earth electrode antenna

Since about 1930z I have been using the (short) earth-electrode antenna on 472kHz.  Baseline is at most 15m, probably less and it runs roughly E-W.  On RX I am seeing F5WK (436km) for the first time and reports exchanged (both ways) with G3WCB (101km) seem to be slightly stronger. Semi-local G0LRD (25km) is spotting me at much the same strength.  PA3ABK/2 is similar on the earth-electrode antenna and the Marconi.   I have yet to spot or be spotted by other stations.

I am matching the loop with a tapped 3C90 transformer and a few turns on a 110mm diameter former, although the Q is so low that this coil is probably not necessary. Antenna current is about 0.4 that with the "short" Marconi vertical. It is probably acting as a loop and I have still to try to work out the ERP.  At this QTH, the earth-electrode antenna looks like a higher resistance than at the old QTH, hence the need for a step-up transformer between transverter and "antenna". At some point, when fit again, I want to try a longer baseline earth electrode antenna and a better Marconi vertical. When fit again - oh please!

I suspect the earth-electrode antenna to be directional, so in some directions it may be better and others worse than the Marconi.  I'll leave it running overnight to see how results compare with the very short Marconi. I suspect results will be worse overall on the earth-electrode antenna, but I may be surprised.

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