|RFI issue spread across the band|
- Switched to my active antenna and I still had the issue.
- I change to battery power only and I still had the issue.
- I turned off the main AC circuit breaker to the house and I still had the issue while using battery power obviously. Oh and an added note.....my dear wife was not happy about that.
|Sometimes the RFI stops but then soon starts|
-Switched to my dummy load and the issue was gone but so were all signals.
So from the above, it seems it is being picked up by the antenna and not something within my home. At this point, I have not tried to pinpoint times as to when or if the RFI is present. I will be within the next few weeks paying very close attention to times when I am on and if the RFI is present or not. Until then I wanted to see if I was able to solve the issue with the Icom 7610's filtering. The choices I have are the noise reduction option or the noise blanker option. As a side note, my previous rig was the Elecraft K3 and it had amazing filtering for RFI issues. It was time to put the Icom 7610 to the test and see how it performed. I tried both the NR and NB and found it was the NB (noise blanker) that did the trick. I was able to totally remove the RFI and still hear the CW signal that was getting buried in the noise. Within the noise blanker settings, you can adjust the level, depth and width. I did find certain settings worked better than others at removing the offending RFI. I did change over to my Elecraft KX3 just to see how it dealt with the RFI and I was shocked how it really was not able to remove the RFI and the Icom 7610 won hands down!
I have included some screenshots of the RFI in the post here and if anyone has any ideas of what it may be or other tests I can do please post a comment. One theory I have is our very close neighbour has what is called down it this way a "split mini". Until I moved to the East coast I had never heard of one or even seen one but they are a heat pump so you have heat in the winter and cool in the summer. It's about 30 feet away from my Endfed antenna but this is just my humble opinion. The trick for me will be to check out the radio when his split mini-cycles off.
I have some blog entries that may help at:
Good evening Dave, thanks for the link looks great and gives very useful tips and actual screenshots of RFI. Funny thing is as I look at the RFI screenshots they all seem to look like what I have. I guess after looking and looking at the pics they all just fade into one. I will check out the website very closely and I hope in short order I will be able to report on the found RFI.
Thanks again Dave and have a good week.
My guess is that it is from a solar panel. What you have is not bad just annoying.
73, Larry WB8LBZ
El Paso, TX
Good evening Larry very nice to hear from you and thanks for leaving a comment, I will have to look around the area here to see if I can see any solar panels on homes. You are correct it is annoying but with the filtering of the 7610 I can remove it totally. I was at you QRZ page as well as I like to do this then folks leave a comment. It helps me learn about those who contact me on my blog. The Landcruiser is in excellent condition and the colour is great too. I was reading over the computers you have and their setups. I only have one and it is the AMD 8350 as well with a Geforce card as well BUT no solid state drives still using SATA drives. I have noticed the prices have come way down on the solid state drives. I did try Win 10 but ended up going back to Win7 pro as I was not happy with how it handled or should I say did not handle my sound card.
Have a great week Larry and thanks again for the comment.
Whenever I encounter RFI – or when I talk to someone who is experiencing it (which is almost everyone, these days) I always ask them to check several things:
– What does it sound like in AM with the noise blanker and DSP noise reduction turned off? Is it modulated with mains components (50/60, 100/120 Hz and harmonics?) Something else?
– What about integer “sub harmonics” of the frequency in question. For 20M, that would be 40 meters (divide-by-two) and around 4.7 MHz, and so on – and also harmonics of those frequencies as well. It’s often the case that the nature of a noise source is revealed more readily at a lower frequency where the power density is likely to be higher.
One of the most offensive, common noise makers that is easily overlooked are battery maintainers sold by the usual suspects (Harbor Freight, Canada Tire, etc.) The very old units (about 10 years ago) used an iron “wall wart” that was RF quiet, but they have long since shipped them with switch-mode warts that seem to be universally bad radiators – getting worse when they are on the verge of failing: I have joked that these units should really be IDing every ten minutes in order to be legal!
If it does turn out to be a variable speed motor or similar in someone’s A/C unit, about the only thing to be done would be to install something similar to a Corcom line filter as close to its mains connection as possible – but this would require the cooperation of a good neighbor to do this. (A ferrite device will likely do little good unless you can get several bifilar turns of mains conductor around it.)
If the noise suddenly appeared from such a unit that was previously quiet, it’s possible that mounting/grounding screws have worked their way loose, but it’s also possible that it’s about to fail in the motor control (bad electrolytics are common – about $10 of parts – I’ve fixed several of these as it’s often the caps and/or inrush limiter) and that the problem will solve itself – albeit expensively for the neighbor.
WOW, Clint! I now have a nice way to spend my day when the rain arrives next week. I have to admit that over the past week and a half I have not dealt with the issue at all. I have had great weather here and many outdoor projects none ham radio related have to be completed. I have been working away at these items but since most if not all are outdoor projects when the rain comes its back to the RFI and your suggestions are fantastic. Thanks for taking the time to outline in a very easy to follow format.
Clint have a great weekend and again thanks.