# OTA HD Interference from appliances



## Michael P (Oct 27, 2004)

Here is a weird one: my 921 will loose audio and sometimes picture too when my dishwasher is running. Whenever the dishwasher starts into a new cycle the audio drops out on at least a few OTA channels including WKYC which is DT on ch 2. I know that analog low band VHF was more succeptable to interference, so I attribute this to the lousy broadcast frequency. 

I'm using an indoor antenna (I can see the transmitter towers out my back window  ), so perhaps an outdoor antenna would mitigate this interference.

Anybody else experience this type of OTA interference?


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## ntexasdude (Jan 23, 2005)

Wow, that is strange.....a dishwasher? The solution is simple, however, just don't use the dishwasher and get the old lady to wash by hand.


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## rice0209 (Oct 11, 2005)

If it is an amplified antenna, check too see if you dishwasher and the outlet you use for the amplifier are on the same breaker. If so, see if you can run power from an outlet that is not on that breaker and test again.


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## DonLandis (Dec 17, 2003)

Rice0209 is on target with that suggestion but I have concerns for the warning you are getting from your 921- Better get a service man familiar with electrical in to look at your Dishwasher. You may have some arcing going on in it's control systems that is generating that interferrence. This could be a source for fire hazard. It could be a simple contained sparking in a relay. BUT, something is not right with your dishwasher's electrical. Have it checked out ASAP. 

Last summer I had a problem with a similar buzzing noise in my HT sound, A week later the thermostat control system on the AC caught fire and I was able to get it stopped quickly. Fortunately, the control relay that burned up was contained inside a sealed metal box in the air handler unit so other than fill the house with a burned plastic smell, no other damage was done.


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## bbomar (Oct 18, 2004)

Low-band VHF is much more susceptible to impluse noise than high-band VHF
and UHF. In fact, it has been recommended that low-band VHF not be used
for DTV transmission:

http://www.mstv.org/docs/techinfo.pdf

However, that said, there is some reason why your dishwasher is generating
impulse noise when it should not. Some sort of arcing is a likely cause which
is a fire hazard. That is why arc-fault breakers are being used in lots of new
construction. Have your dishwasher fixed.


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## Michael P (Oct 27, 2004)

Thanks to all. I had no idea that the problem could be with the dishwasher. I just bought the house this year, the dishwasher came with the house. 

What do I tell the serviceman, after all there is no indication of any problem with the operation of the dishwasher itself? I'd never know that there was a problem w/o your comments.


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## Jason Kragt (Dec 20, 2002)

I don't think that there is any easy way to convince a serviceman of the problem. Be prepared to use some charm and persistence, if necessary.

Could you turn on an AM radio nearby the next time your dishwasher is running? Arcing will usually create a very loud burst of noice on the AM band.

Could you pull out your dishwasher a little and watch it in total darkness? If you could see a flash of light, that would be all the proof you would need.

Has a recall been issued for your dishwasher? Mine was recalled for a possibly similar electrical problem. Check out http://www.cpsc.gov/cpscpub/prerel/prerel.html

Consider yourself lucky--you found the problem pretty quickly. It took months for me to identify my channel 2 interference source. It turned out to be a Microsoft router. I run my LAN cables alongside my coax cables. Somehow, that significantly reduced my channel 2 signal strength or quality. Moving the cables solved the problem.


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## Michael P (Oct 27, 2004)

I think I need a power conditioner. While the washing machine was running I expereinced drop outs on WEWS-DT (rf 15). The washing machine is in the basement, nowhere near the 921 or the coax.

Or it could be my temporary funky rabbit ears set-up. I started out with a Silver Sensor But had problems with the VHF stations. The drop outs began once I hooked up an old pair of rabbit ears plus a UHF loop on a VHF/UHF combiner.


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