[Elecraft] Diversity receive versus QRM eliminators

[gt-i at gmx.net]

Good hint - tnx Frank.
Will try a mini whip or small loop.
73 Gernot DF5RF

Am 29.06.2020 um 19:47 schrieb donovanf at starpower.net:
> Hi Alan,
>
>
> The MFJ works very well as a noise eliminator only if the noise antenna
> is very close to the noise source, so that the noise is much stronger than
> the desired signals. If the noise antenna is receiving about the same
> signals as the main antenna the noise elimination function cannot work...
>
>
> 73
> Frank
> W3LPL
>
> ----- Original Message -----
>
> From: "Alan - G4GNX" <g4gnx at g4gnx.com>
> To: "Elecraft Reflector" <elecraft at mailman.qth.net>
> Sent: Monday, June 29, 2020 5:43:24 PM
> Subject: Re: [Elecraft] Diversity receive versus QRM eliminators
>
> Hi Gernot.
>
> I use an LZ1AQ double mag loop (rotateable) to null out as much hash as
> possible. This feeds the RX Ant In input on the K3S. I also have an MFJ
> Noise eliminator which is also inline, using the LZ1AQ as the main (RX)
> antenna and I've tried a couple of antennas (including my HF vertical)
> as the 'noise' antenna and I don't find any noise suppression by phase
> elimination with the MFJ. I've yet to try a mini-whip antenna as the
> 'noise' antenna. I actually wonder if the MFJ unit is faulty, as I've
> heard that other people have at least noticed a small difference when
> using it. Once/if I get the MFJ untit to work, I may then buy one of the
> more expensive noise eliminators.
>
> 73,
>
> Alan. G4GNX
>
>
> ------ Original Message ------
> From: gt-i at gmx.net
> To: "Elecraft Reflector" <elecraft at mailman.qth.net>
> Sent: 29/06/2020 18:18:30
> Subject: [Elecraft] Diversity receive versus QRM eliminators
>
>> Hello all,
>> In a recent rush to eliminate urban noise I bought an QRM eliminator.
>> The working principle is to null out signals by shifting the phases of
>> two antennas (one main/tx and one rx). I can see the effect sometimes,
>> but it is not the holy grail for all types of QRM. I still don't get rid
>> of the PSU/LED/plasmaish noise here, sometimes the S/N is a bit better
>> but maybe thats my inner impression to justify buying this thing.
>> Now, I do wonder how this differs from diversity receive, effectively
>> versus local QRM.
>> Note I have a 10m vertical as the 2nd ant, while the main ant is horizontal.
>> Any thoughts or hints ?
>> tnx 73 Gernot DF5RF
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to donovanf at starpower.net
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to gt-i at gmx.net