I would also check that his AC common is properly attached to the house ground. Also, I would check that all the screws on the circuit breakers are tight. I say this because he mentioned that he hears appliances in his receive audio.

A few more thoughts: Try to determine which household items are causing noise by switching off circuit breakers to isolate the noise source to a single room; I found a noise-generating wall charger this way. Try ferrites on the power cord of the washing machine, A/C and other noise generators. (I completely cleared up a bad noise problem from a neighbor's big screen TV by putting ferrites on the power cord - glad she let me!). Last, I have used noise cancellers to great effect to null specific local noise caused by electronics. The noise cancellers (MFJ-1026, ANC-4, QRM Eliminator) are amazing devices when used properly. I've used them all. I like the MFJ-1026 and QRM Eliminator because they have gain controls for both the main and noise antennas, making it easier to match the noise level between the two antennas, before nulling out the noise.

A couple of things I found useful, I also use an OCF dipole, first build a mains filter to reduce mains borne interference, plenty of designs using big ferrite and commercial mains filters n series. All shack gear , pc antenna switch wall warts all should be supplied from the same common filtered socket strip. Second , try reversing the OCF so the short end is swapped with the long side, I recently did this to reduce noise from a neighbour’s house , it dropped the noise by 2 s points as you are shifting the current peaks on the antenna elsewhere. Oh and dont mess with the house earthing, its the way it is for a reason.

Just a heads up: tis the season of Christmas lights, and between the LED lights and the incandescent twinkle lights you're going to see evening noise levels with ridiculous numbers. I typically have a +20 noise level on 40, 80, and 160 from Thanksgiving to New Year's Eve.

Dave, good advice. If his shack grounds are good and done correctly, it is still possible that the noise is radiated and picked up by his antenna. Moving the antenna away from the house might help this. But, finding out how the noise is being radiated is important too. I have seen house wiring radiate when the wires are not kept together forming a loop. This is a very bad practice but some homeowners do it. Other than that identifying and eliminating the source devices is the only way to get the noise level down. Good luck to Steve, AA8TJ

All great suggestions. If you can identify how the noise is entering the radio you will avoid unnecessary remedies. An easy way to check the power supply is to power the radio from a battery and see if there is a change. As also noted the BHI noise suppression works well. I recently purchased a Heil Parametric Receive Audio System and matching speaker. Yesterday I installed a BHI noise suppression board in Heil cabinet. Hearing problems had made radio listening painful. I can now listen to shortwave stations again. Also the type of antenna can make a difference. I use a magnetic loop which results in a lower noise floor. Once you find how the noise enters the radio you'll get this resolved.

When I bought the BHI DSP Cancellation speaker It opened a whole new world for me as I age. To me is gets rid of all noise and hardly touches the voice on SSB.

I put torides on my fridge and washer...helped greatly. LG fridges are very bad for noise!

Odd thing about my OCF dipole (about 90' x 180') and it is noisier than my 80 M dipole or my G5RV Dr. By noisier, I am referring to picking up local noise.

I have a very high hf noise level. I built a homemade loop antenna. The mag loop antenna cuts noise by about 5 s points. My loop is mounted at the bottom of my garden well away from the house. Hope this helps Kim G8GRL.

You mentioned to add clamp on torroids on the 12 volt power leads. Would this be at begining were the power leads leave the power supply? Or right at the back of the transceiver were the 12 volt enters the back? Thank you

When you talk about pre-amp I presume you mean a stand-alone pre amp and not the one in the radio??

Variable speed, motors in any type of appliance can put out RFI I myself am plagued on 10m with one of my neighbors air conditioners. I had the power company came out and they figured it out. Although the manager that I dealt with over the phone, was unable to tell me which neighbors air conditioner was giving me the issues he wasn’t the tech that came out and I wasn’t home at the time. I’ve watched a few KZread videos regarding this and often the manufacturer makes special wiring harnesses that can be added between the control board and the variable speed motor. But from what I’m told they have so little complaints. They do not supply it with the new units they say about one in 1000 units they sell well they get an RFI complaint, so they don’t bother, installing the special harnesses on all the units.

@black75powder

8 ай бұрын

So at least your RFI is in your own home, and you could probably combat it at the source. With appropriate chokes and toroid’s on power cables, wiring harness between motors and their control boards.