I am a homeowner with an Over the Air TV antenna. It works great and receives over 100 channels in the LA area. However, when I turn on my living room ceiling fan the high band tv channels become very pixelated. When I turn off the ceiling fan, the channels return to very good reception. The ceiling fan was installed when the house was new by licensed electricians. The wiring goes directly from the fan to a wall switch. I called the ceiling fan company and they have never heard of anyone having this problem. They said is it not likely the switch or fan receiver or remote as they only emit RF when a button is pushed.

Is is possible the fan motor is emitting EM interference affecting the tv reception? Any other ideas would be welcome.

Thanks,

 

Does the switch have speed control?
If so it is Triac switching noise causing the problem.

 

Does the switch have speed control?
If so it is Triac switching noise causing the problem.

The switch has 6 speeds. Interference occurs on all speeds. I do not know what a Triac is.

 

The Triac is an electronic device used in these fan contollers and can be very 'Noisy' due to the electrical switching, this is then transmitted to the motor windings also.

 

The switch has 6 speeds. Interference occurs on all speeds. I do not know what a Triac is.

Yep, that'll do it if there is not enough supression.

 

When I was a teen I made a fan from an old motor. The RF cops came to my apartment and explained that interference from the sparking brushes in the fan's motor was causing radio and TV problems to many people. Then the RF cops confiscated my fan.
I was lucky there was no fine and no jail time. Then friends bought me a fan that had a brushless motor which produced no interference.

 

The easiest thing is to try moving (away and rotated from the source of EMI/RFI) your antenna if it's an indoor model.

 

When I was a teen I made a fan from an old motor. The RF cops came to my apartment and explained that interference from the sparking brushes in the fan's motor was causing radio and TV problems to many people. Then the RF cops confiscated my fan.
I was lucky there was no fine and no jail time. Then friends bought me a fan that had a brushless motor which produced no interference.

Antenna is on the roof with RG6 cable

 

You could try an EMI suppressor, this type, Electrical suppliers, or Amazon have them, it would have to be wired between switch control and motor, preferably close to the switch as possible, but this may be the hardest to do.

 

You could try an EMI suppressor, this type, Electrical suppliers, or Amazon have them, it would have to be wired between switch control and motor, preferably close to the switch as possible, but this may be the hardest to do.

View attachment 272086

Thanks

 

Antenna is on the roof with RG6 cable

Check your house, cable and antenna ground block connections. Check every RG6 cable RF connector for good shield continuity.

 

Indeed, the first thing to do is verify that the noise is entering through the antenna connection, because it may also enter through the power feed. If it is line entry then a power filter can help.
If it enters via the antenna feed then indeed the first step is verify all connections have a solid shield connection. Then check to see how close to the antenna feed is the power wiring.
The only benefit of having a licensed electrician do the work is that it probably will not start a firs or fail a code inspection. That person is in business to make money, not friends, and so the work is done fast. Inside the box there may be a loose connection or a missing ground or shielding not installed adequately.
One diagnostic trick is to try a different feed line running to an outside antenna. If that fixes it then it is time to work on the antenna cabling.

But L.A. is in California and all of the rules are different there.

 

My approach first is to try and remove it at the source. !

 

In a standard electrical wiring box that has a six speed controller in it already there is not much space to install any filtering hardware at all. so while adding adequate filtering is a good plan, the TS is not capable of doing it, and an electrician in that area is probably neither able nor willing to do an adequate installation, in addition to not having a clue. and ordering from amazon demands understanding exactly the specifications of what one needs.

We have no information about the brand or model of the fan, and while some USA fan makers produce good fans with adequate filtering, in other parts of the world some produce junk not good enough for a landfill.
And certainly some builders cut costs wherever they can, including quality.
Thus, while preventing the noise is the best choice, it may be a daunting task at best. That is why keeping it out of the system maybe the fix, but not a cure.

 

That is why keeping it out of the system maybe the fix, but not a cure.

Thats what I like to hear, a positive approach

The OP mentioned "Any other ideas would be welcome." This is one I I would be tempted to try, 'Daunting' or otherwise , if it fixes it it is a 'Cure' !!

 

Was it working fine before? Since it has six speeds, I'm guessing it's a DC motor. DC motors are generally noisier than AC motors.

Maybe adding an EMI filter to the TV/TV receiver is another solution.

 

Most likely the fan motor is a high-slip induction motor, since brush type motors cost more and have much shorter lifetimes between brush replacements, and brushless DC motors require electronic drivers.
So an initial analysis will consist of removing the cover of the control box and seeing how many wires run to the fan motor, and how many wires connect to the speed controller module. That should not be excessively complex, nor demand the services of an electrician.
If the fan only has 2 wires(plus a ground wire), and the controller only has 2or possibly 3, then it is definitely a triac type controller of some sort. That will affect the device toward a solution. Otherwise it is all guessing.

 

, I'm guessing it's a DC motor. DC motors are generally noisier than AC motors.

From my experience, the smaller ones, Bathroom etc, are AC shaded pole motor, the larger diameter room fans have been AC induction also, but PSC , permanent start cap motors.

 

When my plain old ceiling fan with no remote speed controls nor complications is turned off from the plain wall switch, the TV audio mutes for half a second. Antenna is on roof, RG-59, no booster. It is a gremlin. (Murphy's mascot)

 

When my plain old ceiling fan with no remote speed controls nor complications is turned off from the plain wall switch, the TV audio mutes for half a second. Antenna is on roof, RG-59, no booster. It is a gremlin. (Murphy's mascot)

The switching off of the TV sound may be as simple as a line transient generated from switching off the fan motor. If they are on the same circuit that is a real possibility. That may even be the issue in the TS case. Line filtering is an area often unaddressed in consumer products.