>Yes, looks much better than the other antenna. I can see sferics for the first time there, which is a good >step. The LF resonance will have no real effect. So the audio transformer is on the roof and then you >lay out a long cable which is then connected to the soundcard in the shack? 

Not exactly. There is a coax cable from the roof to shack. No transformers at the antenna

The variometer, coil, vertical section and topload hat is all connected to the inner of the coax

Coax ground is connected to the metal pipe which runs inside the building to the basement

>The cable is floating at the transformer end?

The coax cable in the shack is connected to the audio transformer. The other side of the audio

transformer is directly connected to PC soundcard

>Maybe you can use that signal for some time to generate a slower spectrogram covering 0...24 kHz, >with better brightness/contrast adjustment. This would give a better impression about the sensitivity. If >you disconnect the antenna, how much (in dB) does the noise floor drop then?

Measured at 10KHz. From about -110dB with antenna it drops to -135dB without antenna

>Hm, it does not tell to much but it is promising. Also, a spectrogram running at 1 pix/min would give >a better impression.

Yes. I'm doing that. Let's see what can I get

73 de Luis

EA5DOM