LF Active loop in practice.

Have now been using the loop for a few weeks now, have dropped the noise floor around 6dB by choking the loop feeder at the shack end.
Perhaps I'm around the floor now, doubling the loop area has not gained any s/n improvement, results now seem about the same as other UK stations. The loop is bandpass filtered, I have a simple method of sweeping the loop in place. The loop output goes into a HP 141 Spec anal with the Tracking gene driving a 6' square wire loop in the house so I can sweep the loop directly.

I like to view WSPR signals from the Rx so run Spectran alongside WSPR. As we measure signals against the noise background the actual level of the background is of interest. By running Spectran at 0.6Hz b/w and averaging 32 times you can get a sensible smoothed noise level whilst avoiding the bumps from distant NDB's and other steady signals. I'm North of London in a largish town so have a fair number of noise sources all around but most nights able to hear Polish NDB's. Have 30 + MF Rx WSPR spots in the last 2 weeks. Do have a poor direction East because the loop is pointing at Italy so plan a second loop to fill the gap. Seems that each week brings more people onto LF- long may that continue!!

73's and happy wspering
Alan.