Hey Don, QRL? Once you have identified the QRM as a QRM and not QRN it is really just a matter of shifting the phase angle to prevent it from entering the receiver at the front end, correct? Funny story, last July 5th @ 0500 I went out to my truck to check the battery I was charging. When I lifted the hood there was a tremendous explosion and I saw shrapnel raining down on the truck and driveway. First thought, battery blew up. Second thought, fireworks still being ignited from the July 4th parties. Then I noticed the entire area was strangely quiet even for 05:00. When I saw the shrapnel I knew what happened. A ceramic insulator on the power pole right above me failed and allowed the stress loop to be pulled and contact the pole. The boom was tremendous and happened at the exact moment I opened the hood. The inside of the insulator was covered in arc marks that had pitted it fairly deep, so I guess it had been going on for a while. OK gotta run. XYL is at my 20. 73 sir.
McDave, not busy. :-)... in this case, the QRN is QRM given it is rather strong, is man made, and interfering. The noise canceller has a differential amplifier inside and when you invert one input (via phase adjustment)and feed it through along with an similar signal that is not inverted, only the differences are amplified which should be minimal if the inputs are adjusted well and the noise source is nearby and reaching both antennas in same phase. Long distance signals sometimes arrive via multiple paths due to reflections and etc.. so they do not get canceled out completely although they may be attenuated some. It is not ideal, but is good enough most of the time. The differential amplifier has an inverting and non-inverting input so to get no difference on output, one input needs to be inverted... at least that is what I can make out from the schematics. Ever thought about getting your Amatuer Radio license? You might really enjoy it. I chat with folks all over the country and world for that matter. Just really cool to do that with no phone lines, satellites, or technology other than my radio and an antenna. That power pole was probably very noisy from an rf perspective before it blew out. Something like that is going on near me..loose hardware or a bad insulator on the high voltage side of the transformers are nothing but spark gap transmitters. The very first transmitters were spark gap transmitters. Marconi used one for his historic transatlantic wireless communication.
i got real bad qrm from my neighbor who has a first generation solar system plus power poles. It sucks - I can only talk to local people in my area. but I might be forced to try this MFJ Device
It should work for you. It is a learning process to get adjusted and it is crucial to use a good external antenna for the noise reception. On a side note, work with the ARRL on your noise issue. The manufacturers of those systems should have free fixes for QRM for thier solar systems. The ARRL will contact FCC if they do not fix. That is unacceptable. It is a process and will take some time.. but the reality is they have an illegal broadband transmitters interrupting the HF bands.
uzywam ten eliminator i moge powiedziec, że jest znakomity.W pasmie 80 od roku mam bardzo duze zakłócenia lokalne silne smarzenie na paru MHzach uniemozliwiające całkowicie łączność na 80m.(59+25dB) dzień i noc. Pojawiły się nagle. Duzo experymentowałem z 1026 i najlepsze rezultaty osiagnalem przy dwoch bazookach Smarzacy QRM zbijam do zera przy normalnej sile stacji .Jako external antena miałem tez LW 10metr,ktory działał dobrze ale nie tak dobrze jak te bazooki. Było u mnie UKE i też stwierdzil zakłócenia od strony drugiego sasiada i na tym sie skończyło. Panowie nie są chętni do pomocy.= jeśli ktoś ma podobne problemy to polecam ten eliminator- SP9DTI
Hey Don,
QRL? Once you have identified the QRM as a QRM and not QRN it is really just a matter of shifting the phase angle to prevent it from entering the receiver at the front end, correct? Funny story, last July 5th @ 0500 I went out to my truck to check the battery I was charging. When I lifted the hood there was a tremendous explosion and I saw shrapnel raining down on the truck and driveway. First thought, battery blew up. Second thought, fireworks still being ignited from the July 4th parties. Then I noticed the entire area was strangely quiet even for 05:00. When I saw the shrapnel I knew what happened. A ceramic insulator on the power pole right above me failed and allowed the stress loop to be pulled and contact the pole. The boom was tremendous and happened at the exact moment I opened the hood. The inside of the insulator was covered in arc marks that had pitted it fairly deep, so I guess it had been going on for a while. OK gotta run. XYL is at my 20. 73 sir.
McDave, not busy. :-)... in this case, the QRN is QRM given it is rather strong, is man made, and interfering. The noise canceller has a differential amplifier inside and when you invert one input (via phase adjustment)and feed it through along with an similar signal that is not inverted, only the differences are amplified which should be minimal if the inputs are adjusted well and the noise source is nearby and reaching both antennas in same phase. Long distance signals sometimes arrive via multiple paths due to reflections and etc.. so they do not get canceled out completely although they may be attenuated some. It is not ideal, but is good enough most of the time.
The differential amplifier has an inverting and non-inverting input so to get no difference on output, one input needs to be inverted... at least that is what I can make out from the schematics.
Ever thought about getting your Amatuer Radio license? You might really enjoy it. I chat with folks all over the country and world for that matter. Just really cool to do that with no phone lines, satellites, or technology other than my radio and an antenna.
That power pole was probably very noisy from an rf perspective before it blew out. Something like that is going on near me..loose hardware or a bad insulator on the high voltage side of the transformers are nothing but spark gap transmitters. The very first transmitters were spark gap transmitters. Marconi used one for his historic transatlantic wireless communication.
I'm not sure what language you are speaking Don but, it sounds pretty cool!😂
Lol.. thanks. Yes, you'd probably have to be into Amateur Radio to even care. 🙂
@@donsdoityourself2547 that's always been something I've wanted to learn about.
i got real bad qrm from my neighbor who has a first generation solar system plus power poles. It sucks - I can only talk to local people in my area. but I might be forced to try this MFJ Device
It should work for you. It is a learning process to get adjusted and it is crucial to use a good external antenna for the noise reception.
On a side note, work with the ARRL on your noise issue. The manufacturers of those systems should have free fixes for QRM for thier solar systems. The ARRL will contact FCC if they do not fix. That is unacceptable. It is a process and will take some time.. but the reality is they have an illegal broadband transmitters interrupting the HF bands.
uzywam ten eliminator i moge powiedziec, że jest znakomity.W pasmie 80 od roku mam bardzo duze zakłócenia lokalne silne smarzenie na paru MHzach uniemozliwiające całkowicie łączność na 80m.(59+25dB) dzień i noc. Pojawiły się nagle. Duzo experymentowałem z 1026 i najlepsze rezultaty osiagnalem przy dwoch bazookach Smarzacy QRM zbijam do zera przy normalnej sile stacji .Jako external antena miałem tez LW 10metr,ktory działał dobrze ale nie tak dobrze jak te bazooki. Było u mnie UKE i też stwierdzil zakłócenia od strony drugiego sasiada i na tym sie skończyło. Panowie nie są chętni do pomocy.= jeśli ktoś ma podobne problemy to polecam ten eliminator- SP9DTI
Good to hear that the noise eliminator worked for you also. The key is a good external noise antenna like the bazooka.