Furnace Blower RFI - Suggestions?

Dave - N6XVZ

KC2QMA_John

Andrew O'Brien

Chuck

Dave - N6XVZ

Chuck Appx 24.8 to 31.8 MHz. So 7mhz. Huge. Peaks every 15 kHz. It seems like such a large range vs what others including you mention seeing. I do have to ferret out the motor mfg. one can hope it is the same mfg. Really the only wires exiting the enclosure are Thermostats and power. But will keep them in suspicion.

N8SDR

Dave, Have you looked at whole house AC filters  something like the Morgan 330 units, http://www.surgestop.com/surge-products/m-330.html  . I think someone else now builds there products - I have a few of the 400 series and they seem to work at taking out or reducing  issues I have had. and will probably add the 330 as well.

Larry _ NY8T

My washer/dryer combo did this until i put some mix 31 snap ons on the 240vac power cable right up to the back panel. This prevents the motor that is emmitting rfi to use the power cable as an antenna and transmit it farther and stronger.

Mark Aaker K6UFO

Ed Johnson

I had the same problem.. Popped open the inside unit and installed 10 split ferrites Mix 31 on all wiring harnesses that I could get to..... including wires to thermostat (great antenna).  Problem is history.

Andy - KU7T

Chuck

Dave,
I have seen the EMI extend 7 MHz and more.  The peaks from the EMI emitting motors consists of clusters of many very narrow pulses (~50) spanning approximately 1 KHz.  And, these pulse group repeated approximately every 18 KHz over many MHz.  The noise signature I see in your photo above is different from anything I have seen coming from my HVAC motors.
Chuck

Dave - N6XVZ

Patrick

After reading the various comments and sujestions, most are what I would have done, there is one more thing you should do. Report this to your FCC field office and give them all the details of what you have done. With the current political regime in office. All prevention regulations at the various regulatory agencies have changed to self regulation policy. So the only way to get action on an issue is to report problems or proceed with legal action.

Dave - N6XVZ

Pat- One of the hot topics in our community besides merits or lack of them for FT8, or people constantly changing call signs and locking them out or.... Is whether this device falls under FCC regulations or not. I find arguments on both sides and struggle to overcome my apathy to convince FCC and MFG of their error For example see slide 30 of the ARRL preso I listed at the start. It claims no standard for incidental emissions below 30mhz. I haven’t found any good examples of how one of us has pursued this path and made a difference. Tnx

k3Tim

AB9UU

I may have the same problem but from a neighboring building. Roughly for 11- 15 minutes at a times, I get interference mostly on 40M all day and into the night (go to bed early if I can). I included a link to the video or just check AB9UU.USA on YouTube. I think it might be the furnace motor of the building across the street but am unsure so far. It is cold out now (below 0 F tonight - ouch) and the furnace motor may be running at these intervals unless it is something else. When I turn my Hexbeam between 340 and 20 degrees and select 40 meters, I get the interference in the video though the video is from my End Fed antenna. Still, it looks very similar. You can even see the "switching on" of the interference. I still need to pin point it but I believe it is the building across the street as it is in the degree range of the Hexbeam pattern. https://youtu.be/zQrHS88q-dM