Frequency Interference
Frequency Interference
(OP)
I recently noticed my two garage door remote controls were not working. Before I had a chance to call for service and after resetting the remote controls, my neighbor called and told me that 7 houses adjoining each of us had the same problem. He had contacted the company that installed his and was told there was nothing wrong with his garage door openers and someone in the area had some device emitting a large amplitude signal in the bandwidth the remote controls were operating in. I contacted the FCC and was told by a very rude rep that they did not investigate issues like this and to contact my local police and report it. Right!!!. The only recourse I can think of doing is either renting a spectrum analyzer with a directional antenna and locating the source or replacing the unit. Can anyone think of anything else I can do? Even finding this source, how can I enforce the elimination of the signal?
Any help from you guys would be greatly appreciated.
Thanks
Any help from you guys would be greatly appreciated.
Thanks





RE: Frequency Interference
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Frequency Interference
Assuming that this is the case here, it's actually their frequency so there's not much to do except contact the local garage door vendors to see if they can offer you an external receiver on another frequency.
This has been in the tech news recently in various locations so you might want to dig into it using the above info to help confirm the cause. Google garage door and radar to see what you see...
RE: Frequency Interference
RE: Frequency Interference
http://www.arrl.org/
RE: Frequency Interference
http://www.arrl.org/
RE: Frequency Interference
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Or it could be something else...
RE: Frequency Interference
I just can't imagine anyone using a Military frequency for a garage door opener! The Military are not known for low power operation.
I suppose these devices are coded so your opener doesn't open your neighbour's garage door. Then we are just talking about raw carrier wave power jamming the signal. This means either getting really close or using a highly directional yagi (which at 390MHz would be huge!)
Interestingly, this is "nobody's fault", ie nobody will pay for it except Joe Public.
RE: Frequency Interference
Around all ISM channels there are fixed governement channels. If one of the governement channels bleeds over ISM channel there may bean interference because the governement channel is more likely running at maximum FCC power permitted (1,000 miliwatt) while Garage Door is transmitting at less than 30 miliwatts power level, but at the same frequency of Military transmission (or one of harmonics).
Regards,
Bursa
RE: Frequency Interference
Then again, garage door systems are the realm of super-regenerative receivers; about as low tech as you can get.
RE: Frequency Interference
perhaps there is an error in the translation.
When I said ...
"I just can't imagine anyone using a Military frequency for a garage door opener!"
This was an idiomatic way of saying "I can understand that some people are so dumb that they would do this"
RE: Frequency Interference
RE: Frequency Interference
In effect it means, you can certainly use that frequency, but if the primary user (Military) is causing interference, tough luck.
It also means that if you push your garage door opening button, and it interferes with the military service, the FCC or the military will track you down, and shut you down.
A friendly ham operator can probably confirm the source, but I doubt if there is anything you will be able to do about it, if it is a government produced source of interference.