DJ8WX’s page referred to below is reported by my system to be an “attack page”.
> On 18 Sep 2015, at 19:00, [email protected] wrote:
> hi Stefan,
> pse see
> Von: DK7FC <[email protected]>
> Gesendet: 15.09.2015 16:17
> An: <[email protected]>
> Betreff: LF: Active E field antenna versus T antenna for LF/MF reception
> Hi all,
> Since a while i'm now comparing RX results between two omnidirrectional
> E field antennas. One of them is active (similar to the PA0RDT antenna),
> the other one is a T antenna, resonanted to the frequency of interest
> and matched to 50 Ohm... (So the T antenna could be used for
> transmitting). The small active antenna is inside a plastic tube, so
> (charged!) raindrops do not fall on the probe directly. The charge can
> flow to ground through the weak conducting water layer (probably in the
> range of 1E8 Ohm?).During rain i saw that the "QRN" was significantly
> higher on the T antenna.
> So, could it be a better idea to use an active antenna (with a limited
> large signal capability and a non-perfect linearity!) instead of a
> "real" or "traditional" band-selective T antenna? Maybe worth to compare
> the results on a stereo RX ;-) I my imagination i see the active antenna
> with an umbrella to protect from rain (charged drops, |q| > 0). As
> higher the distance between probe and umbrella, the better the noise
> reduction and the lower the signal loss?
> Time to build and test the performance of an active E field probe
> consuming 5V/1mA...
> Just some thoughts...
> 73, Stefan
Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and ROBSONNE