Intefearance reducing/anti jamming antenna
Intefearance reducing/anti jamming antenna
Reason: No reason
Re: Intefearance reducing/anti jamming antenna
Yes, it works like perpetual motion machines, free energy gadgets and the like. It is difficult to invent new things that really work in antennas!
Reason: No reason
Re: Intefearance reducing/anti jamming antenna
I'd like to see an 'equivalent circuit' to that, as I can't work out what is meant to be happening. It looks like (perhaps) it's a version of the QRM eliminator idea, where a null is introduced into the radiation pattern of the radio's antenna by combining the signal from the other antenna in antiphase. It'll probably do something but it will depend greatly on each individual noise situation. I suppose you adjust it by moving the second antenna.
I use two antennas, one is a loop the other is a wire for picking up noise. The signals from both are combined in a control unit in the shack and the amplitude and phase are adjusted to null out the noise.
I use two antennas, one is a loop the other is a wire for picking up noise. The signals from both are combined in a control unit in the shack and the amplitude and phase are adjusted to null out the noise.
Reason: No reason
Andy
Re: Intefearance reducing/anti jamming antenna
That's the only way to get rid of at least partly the RF noise polluting our environments today. You have to carefully adjust phase and amplitude of the auxiliary antenna to achieve a decent notch effect for the noise part. This is simply impossible with such a construction shown in that "Anti Jamming Antenna". Sorry, but such "constructions" are useless.g1hbe wrote:I use two antennas, one is a loop the other is a wire for picking up noise. The signals from both are combined in a control unit in the shack and the amplitude and phase are adjusted to null out the noise.
Even sophisticated two antenna arrays with phasing/noise cancelling circuits have their limits. You only can reduce one noise source from the neighbouring houses. But nowadays all houses around you have strong sources of noise and you cannot catch all of them with the phaser/noise cancellor.
In this context: There is still no noise cancelling feature by phasing and spectral subtraction available for the RSP duo (except for some Linux experimental software which not everybody can use). This would bring noise cancelling to the market at an affordable price.
73, Heinrich
Reason: No reason
Re: Intefearance reducing/anti jamming antenna
The scheme only works if the interference is in one direction, if you have two sources, then it can only null one. The circuit can be tuned to null two sources, but would be very trick to do. A much less complicated solution is a plane loop antenna, which will null the noise source as well, much easier to use and typically has a deeper, sharper null.
Reason: No reason
Tony
AA9CC
AA9CC