Thursday, April 26, 2012

Indoor wire antenna for WSPR

WSPR is a wonderful tool for comparing HF antennas. I "spot" and get "spotted" all around the globe running just 2W into my outdoor wire dipole on 20m. A few stations are often very strong and I wondered if I could be active with just an indoor end fed wire.

About 10m of wire running around the book shelves tunes up nicely with the ZM-2 Z-match tuner. A 1.5m counterpoise runs around the floor.

Despite all sorts of local electrical noise in the room from fluorescent lights and computers I'm hearing Ross, VK1UN (in Victoria) pretty well.

VK4BV and VK1UN are both decoding me 700km away in opposite directions north and south.

Note that previously VK4BV had me at +10db SNR and now I'm -9 so that's much worse but due to the huge dynamic range WSPR can handle it's great to get a reading at all.

Later it's getting better:

WSPR provides a good platform for evaluating indoor antenna options.

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