This is a very wideband antenna and

This is a very wideband antenna and total MW and HF spectrum is applied at its input. I measured the wideband power at the amplifier output (1m diam., 4 uH loop) with thermocouple power meter (HP432A). In urban environment Pout = -22 to -29 dBm depending from the time of the day ( night time is higher). In rural places Pout is from -24 to bellow -30dBm. (An active GSM handy induces -15 dBm when 1 meter from the loop.) These are averaged values and the peaks can be much higher.I do not have an access to good measuring equipment to obtain reliable figures for the 2nd and 3d order distortions. What I have done is to check carefully whether there are any signs of such distortions on the band. I checked the 2nd order products (F1+F2 and 2F ) which might exist as a spurious signals in 14.400 – 15.200 MHz band as result of action of the strong broadcasting stations on 41 m band with frequencies 7.200-7.600 MHz. The important condition is that there must be no propagation on 14-15 MHz band to be sure that all existing signals are spurious. Night winter time is most suitable for this experiment. This test was performed several times at night time with SDR (Winrad) which is very convenient for this purpose. The SDR RX has input narrow band pass filter (200 KHz BW at 14.7 MHz with attenuation > 35dB for 7 MHz) to avoid direct second harmonic mixing. Fig.7 shows the results of this experiment. All candidate spurious frequencies should be multiples of 5 KHz since this is the distance between broadcasting frequencies. I used a 60m long wire (LW) antenna connected through the antenna tuner directly to the SDR input for reference. At start the LW antenna was switched on (upper part of the waterfall display). Then the active loop was switched which is well seen on the picture. (lower part of the display). There are probable very weak spurious traces at 14660, 14720 and 14740. 14730 exist in both cases so it is real signal. If the band is open these spurious signals will be buried in the band noise. A slight noise probably from pulse PS is seen very well on the LW antenna. Seemingly there is a “reduction” of this noise when the loop is activated. But it should be considered that the noise floor of the loop in this case is at least 10 -15 dB above the noise floor of the LW antenna.3-d order distortions (2F1-F2) can also be found in this way but they are buried in the same 41 m band. There are chances to find such spurious products in the vicinity of the BC band . I tried to identify light carriers that exist on the amateur 40 m band and are multiples of 5 KHz but do not find an obvious candidate for such case in this natural experiment.