Gernot, Why ? Generally you need to make sure you are not overloading/destroying RXin K3.
73 Andy HB9CVQ -----Original Message----- From: [email protected] <[email protected]> On Behalf Of [email protected] Sent: Montag, 29. Juni 2020 23:37 To: [email protected] Subject: Re: [Elecraft] Diversity receive versus QRM eliminators Andy, mni tnx - good ideas! Will rewire my QRM box to the K3 RXIn out to avoid the extra PTT-relay clicks imposed by the QRM-box. It is the Wimo-QRM Eliminator. Not as Hi -end as the NCC-1 but a start. Just looked-up the DXE - now the NCC-2 is out and it now also has the same extra PTT switching as my cheap box! Why is this required, as I just learned the K3 can handle this smoothly? tnx 73 Gernot DF5RF Am 29.06.2020 um 22:51 schrieb [email protected]: > Hi All, > > I use in my K3S the RX in and RX out (RCA plugs) on the backside for > inserting the denoised signal from my DXE NCC-1 Phasing Box output plug. > This box has two channels, were one can do e.g. up to -180deg phase > reversal. CH A and B signals are finally send to an internal power > combiner and to K3S RX in. > > My have 2 selectable TX/RX antennas, 2x36m tuned doublet 160 to 6m @ > 24m center and a Steppir DB18E @ 18m. > RX signal come out safely from K3S RX (out) going to CH A NCC-1. > My QRM local noise pick-up ant is a 1m diameter ALA 1530 electronic mag. > loop (predominantly picking up local noise, no DX , horizontally > mounted in the attics, about -60dB decoupled from TX antennas) This > signal goes into CH B of NCC-1 By carefully equalizing/adjusting the > amplitudes CH1 /CH2 NCC-1 I then try do "Anti Phase". This will mostly > reduce the local noise on the used main antenna. > > The limitation is you can only effectively focus (phase) on one > single local QRM source. The unit NCC-1 is good up to around 17m Band. > It is hard to get more than 20dB S/N (about 2.5 S-Units) improvement. > > In some local noise cases, not being a point source (Line source : PLC > , VDSL etc. ) I am more successful using a LISN ( EMC , Line/Mains 50 > Ohm stabilization, decoupling network, 230V, 50 Hz) to safely replace > the signal from the mag. loop. > This procedure picks up the conducted noise on the mains in the > house/flat more in an integral way. This does not act as a "point source" > > Experiments with predominantly E-field ( small/short dipole antennas) > for local noise pick up are ongoing. > > 73 Andy > HB9CVQ, DK2VQ, AK4IG > https://www.qrz.com/db/HB9CVQ > > > -----Original Message----- > From: [email protected] > <[email protected]> On Behalf Of [email protected] > Sent: Montag, 29. Juni 2020 19:51 > To: Elecraft Reflector <[email protected]> > Subject: Re: [Elecraft] Diversity receive versus QRM eliminators > > Diversity is not helpful as a QRM eliminator. > > > Antennas with steerable nulls can be helpful, small loop antennas have > very deep nulls but also require a high gain, low noise figure preamp > and very careful attention to common mode rejection during > installation > > > 73 > Frank > W3LPL > > ----- Original Message ----- > > From: [email protected] > To: "Elecraft Reflector" <[email protected]> > Sent: Monday, June 29, 2020 5:18:30 PM > 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:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email list: > http://www.qsl.net/donate.html Message delivered to > [email protected] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [email protected] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
