Microwave Oven Disables Silver HD Box
chiques
Enthusiast - Level 3

I warm something up in my microwave oven and it completley disables my HD box. I have two other SD boxes that work fine.

Anyone have an explanation for this?

0 Likes
1 Solution

Correct answers
Re: Microwave Oven Disables Silver HD Box
chiques
Enthusiast - Level 3

Turns out the problem was my signal was so weak at the RF coax that any interference within the operating frequency (or even small harmonics) would kill the signal. 

The problem was I was using a 200-500MHz splitter. The Verizon FioS system needs a 1GHz rated splitter. 

Before I was measuring -8.9dB (yes, it's amazing the system was still able to operate with this gain)

After replacing the splitter the tech was able to get a +6db reading. Now I can use my microwave oven and watch tv at the same time 

Smiley Happy Smiley Happy

Smiley Happy Smiley Happy

View solution in original post

Re: Microwave Oven Disables Silver HD Box
retiredme
Specialist - Level 1

Just on the face of it, it looks like a case of electrical interference, common from microwave ovens and many other appliances. I Googled the problem and even saw an instance of a treadmill causing problems. Any electric motor will emit a certain amount of emi, and microwaves are emi generators.  Are you sure it is affecting the DVR , or could it be the TV instead? Have you tried different electrical outlets? It would seem that your SD components are on different circuits than the HD one, which might be on the same circuit as the micro. A no-cost solution would be to change the electrical outlets if that turns out to be the problem. Next solution would be some filtering devices for the plugs and outlets. This article discusses the issue in general terms.

http://www.ehow.com/how_10005716_block-electrical-wiring-interference.html

I am not an electrician, but there could be a bigger problem such as improper grounding in the electrical syem.

0 Likes
Re: Microwave Oven Disables Silver HD Box
chiques
Enthusiast - Level 3

Hey retiredme,

Thanks for the reply. The oven operation is definitely affecting the DVR box. The reason I can rule out the TV is because when my scheduled DVR recorded programming is in progress, if I use the microwave oven it will cause the recording to glitch-stop and freeze up until the program is complete. I usually find this out when I go back and watch the program I recorded.

My house has brand new wiring (with a 7 ft grounding rod as reference). My entertainment center has dedicated outlets with its own breakers so there is very little probability the outlets are on the same rail. 

The filtering solution sounds interesting. I'm not sure if they make AC appliance filters for microwave noise. I'll look into that.

I appreciate the feedback.

0 Likes
Re: Microwave Oven Disables Silver HD Box
PJL
Master - Level 3

@chiques wrote:

Hey retiredme,

Thanks for the reply. The oven operation is definitely affecting the DVR box. The reason I can rule out the TV is because when my scheduled DVR recorded programming is in progress, if I use the microwave oven it will cause the recording to glitch-stop and freeze up until the program is complete. I usually find this out when I go back and watch the program I recorded.

My house has brand new wiring (with a 7 ft grounding rod as reference). My entertainment center has dedicated outlets with its own breakers so there is very little probability the outlets are on the same rail. 

The filtering solution sounds interesting. I'm not sure if they make AC appliance filters for microwave noise. I'll look into that.

I appreciate the feedback.


I guess I would be more concered that the microwave it putting out that sort of EMI (the interference causing the issue on the STB) in the first place.  The microwave apparently has a power supply in it that has a problem that is leaking back into your house power grid.   The fact that your entertainment system is on a different "rail" would not necessarily preclude feedback to the other side of your service (the other rail).  And even though your wiring is new, that doesn't mean it doesn't have problems unfortunately.  It wouldn't be the first time, for example, that outlets are wired backwards.  I've seen that myself.

0 Likes
Re: Microwave Oven Disables Silver HD Box
lasagna
Community Leader
Community Leader

Three things I would investigate ...

1. Is the STB affected by the distance of the Microwave?   If you move the STB to another loction or relocate the Microwave, does the behavior change?  If so, then I'd definitely be concern about what might be leaking from the Microwave either back into the home or even directly.  

2. Have you examine the Coax run feeding this STB?   Do you have a broken shield shield somewhere that is letting interference into the system?  Do you have an unterminate cox outlets?   Where does the coax run (thru the wall, etc.) relative to the Microwave? 

3. Have you checked each outlet to insure there isn't any kind of ground or wiring fault?  One of those inexpensive little plug in widgets with three little LED lights on them (usually red and two yellow) will quickly diagnose the wiring of a recepticle and grounding.

0 Likes
Re: Microwave Oven Disables Silver HD Box
chiques
Enthusiast - Level 3

Turns out the problem was my signal was so weak at the RF coax that any interference within the operating frequency (or even small harmonics) would kill the signal. 

The problem was I was using a 200-500MHz splitter. The Verizon FioS system needs a 1GHz rated splitter. 

Before I was measuring -8.9dB (yes, it's amazing the system was still able to operate with this gain)

After replacing the splitter the tech was able to get a +6db reading. Now I can use my microwave oven and watch tv at the same time 

Smiley Happy Smiley Happy

Smiley Happy Smiley Happy

Re: Microwave Oven Disables Silver HD Box
ElizabethS
Moderator Emeritus

Thanks so much for coming back and posting! I'm sure that will be really useful information for other members.

0 Likes