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Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 9:43 AM

I hope this is the right place to come for suggestions. I did an internet search and your forum popped up. Several blocks of our neighborhood has loss use of older key fobs and the use of keypads or remotes for our garage door. The wired opener still works.

Any ideas of what could cause such a large area of RFI? Any local resources we could contact to help trouble shoot? We’re in Spokane/Cheney, WA

Sincerely,

Jeremy

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#1

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 9:58 AM

First you must know the frequency band and type you have...

https://en.wikipedia.org/wiki/Garage_door_opener

..."To address homeland defense needs and comply with government direction that agencies use the electromagnetic spectrum more efficiently, the Department of Defense (DOD) is deploying new Land Mobile Radios to military installations across the country. The new Land Mobile Radios operate in the same frequency range--380 Megahertz (MHz) to 399.9 MHz—as many unlicensed low-powered garage door openers, which have operated in this range for years. While DOD has been the authorized user of this spectrum range for several decades, their use of Land Mobile Radios between 380 MHz and 399.9 MHz is relatively new. With DOD's deployment of the new radios and increased use of the 380−399.9 MHz range of spectrum, some users of garage door openers have experienced varying levels of inoperability that has been attributed to interference caused by the new radios. Nevertheless, because garage door openers operate as unlicensed devices, they must accept any interference from authorized spectrum users."...

https://en.wikipedia.org/wiki/Land_mobile_radio_system

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#7
In reply to #1

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 1:10 PM

Then why are keypads nonfunctional?

This would have to be an interference across many communication platforms all at the same time. I strongly suggest a master system fail.

How close to Fairchild AFB are you?

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#15
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:13 PM

The wireless keypads don’t work, but the wired ones inside the garage do. We are close to both Fairchild and the the international airport, but the key fob issues on some cars go away when they get closer to the airports. Our gas/electric is remotely monitored but the whole subdivision isn’t having this problem. It is several blocks with dozens of homes though.

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#18
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:36 PM

Ah, automobile key fobs nonfunctional, but operate when distance is increased, proximal to Fairchild AFB...

Might be (probably is) something to post #1.

In your neighborhood, the A/V gear, cell phones, dog shock collars, game consoles... any irregularities with these?

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#46
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/09/2018 9:34 PM

You forgot to mention cable TV boxes,,,

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#27
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 5:26 PM

"Although the sign does not give further details about the type of activity the U.S. Navy is conducting in Southern California, it may be linked to the Enhanced Position Location Reporting System (EPLRS) a secure, jam resistant, network of wireless tactical radios (first fielded by the Army in 1987) that distributes digital data and position location and reporting, between many mobile users.

In fact, the EPLRS/SADL (Situation Awareness Data Link – used by combat planes to interface with EPLRS for ground force support mission) uses a 3 Mhz wide pulse, right in the 433 band where European and Asian cars remote operate.

Identified as the source of interferences with garage door openers is instead a new radio system, known as Enterprise Land Mobile Radio, that is being used at most U.S. military installation reportedly to connect military servicemen and civilian first responders.

The problem has been reported around several stateside military installations, in fact some devices (including garage openers) work legally at the same frequencies used by the ELMR, although they are not licensed to do so."

https://theaviationist.com/2012/08/01/usn-jamming/

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#29
In reply to #27

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 6:02 PM

Now that’s interesting. Good find.

Throwing ya a GA for that, and throwing another to #1.

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#31
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 7:52 PM

Thanks!

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#2

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 10:57 AM

If this neighborhood is a single development, the access control may be a centralized management in lieu of 'access right stored on lock' type.

While this is sort of unusual, this is the only way that I can think of that all access control devices would stop working at the same time.

This means there is some location with a computer that controls all of the access and monitor functions - there has been some sort of failure, and it needs to be reset.

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#3

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 11:00 AM

considering it's a group area that's affected, possible a power surge that wipes out the memory?..., I don't know how old your garage door opener is, but they do use what's called a 'rolling code' to deter someone jacking your RFI code.

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#4

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 11:04 AM

The key fobs should be tolerant to RFI as mentioned but even so, they should still work at close proximity to the receiver in the opener. If they don't work at close proximity I would suspect other issues. More likely the issue is basic such as battery failure due to extreme heat or cold or lightning damage or even intentional sabotage. One possibility is that a very strong RF signal on the same frequency damaged the receiver circuit but the openers should be tolerant to that as well.

If you suspect that a strong radio signal is interfering you can confirm it by use of an SDR dongle. As mentioned most openers work around the 300 to 400Mhz range and USB devices that cost in the $20 range can be purchased on Amazon or elsewhere that can easily confirm this and help further troubleshoot the issue. With a pc running free software and the SDR device, you can tune to the frequency and observe the signal from the opener as well as any other interference on the same frequency or close by. If you do find a strong signal causing the issue the SDR receiver may be able to help identify what and where it is coming from.

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#6
In reply to #4

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 12:33 PM

Add an inexpensive Yagi television antenna to the Software Defined Radio dongle and your laptop PC and you will have a rudimentary DF (direction finding) rig. You will probably need a balun to convert the balanced output of the antenna to the unbalanced input of the dongle and probably an adapter from the F connector of the balun to whatever coax jack is used on the dongle (maybe SMA or SMB, etc.)

This does sound like your door opener receivers are being swamped by a much stronger signal.

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#5

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 11:38 AM

Welcome to CR4! Our members enjoy figuring out puzzles like this one; you'll get some excellent answers. Please check in and let us know how the story ends.

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#8

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 1:24 PM

You said, " lost use of older key fobs and the use of keypads or remotes for our garage door. The wired opener still works.

Isn't the keypad hard wired into the opener, or does it transmit a wireless signal?

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#13
In reply to #8

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:07 PM

The keypads outside are wireless and are inoperative. The wired buttons inside the garage still work.

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#9

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 1:24 PM

Solar flare?

Ok.. mebe not

..interesting indeed....

Someone with a big bad mama jammer?

I've heard about those.

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#10
In reply to #9

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 1:49 PM

especially when the whole neighborhood loses it....

Someone with a big bad mama jammer?

EMP?

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#11
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 1:58 PM

An area of several city blocks is involved, and there is no report of other electronic equipment going dark.

The OH door remotes are described as older... if these are the dip switch code type, most of those operate at 310 MHz, outside the range of the land base mil comm.

I wonder what George Tsoukalos would say?

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#12
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:02 PM

A company where I us to work back in the 90's had problems with their garage doors on their building kept opening up... the company that installed the garage door opener said it could have been the radio signal from a planning flying over head???...

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#16
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:13 PM

Could be possible I suppose.

I installed an intruder detection system years ago that would go to (false) alarm in the middle the night, Tuesdays and Thursdays only. We discovered a HAM radio setup about half a klick away - the hardwires of the detectors were acting as an antenna, and the pulses were being read by the controller as tampering.

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#17
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:26 PM

maybe that's why one of the reasons they switch to a rolling code (aka hopping) type security...

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#19
In reply to #17

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:43 PM

The rolling code TX/RX scheme available today pretty well defeats the code grabber technology that can intercept the dipswitch scheme of signal coding.

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#23
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 4:23 PM

Not really....

..."Rolljam vulnerability ....

A rolling code transmitted by radio signal that can be intercepted can be vulnerable to falsification. In 2015, it was reported that Samy Kamkar had built an inexpensive electronic device about the size of a wallet that could be concealed on or near a locked vehicle to capture a single keyless entry code to be used at a later time to unlock the vehicle. The device transmits a jamming signal to block the vehicle's reception of rolling code signals from the owner's fob, while recording these signals from both of his two attempts needed to unlock the vehicle. The recorded first code is forwarded to the vehicle only when the owner makes the second attempt, while the recorded second code is retained for future use. Kamkar stated that this vulnerability had been widely known for years to be present in many vehicle types, but was previously undemonstrated.[2] A demonstration was done during DEF CON 23.[3] "...

https://en.wikipedia.org/wiki/Rolling_code#Rolljam_vulnerability

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#26
In reply to #23

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 4:59 PM

Yes really.

Rolling code was developed to defeat a code grabber. Guy still wants to get into your house so new technology is developed to defeat rolling code, this a roll-jammer

It is just the cat-and-mouse game of getting one step ahead of the other guy.

The point of diminished return is near, soon thieves will realize that a tire iron will defeat pretty much any technology deployed to secure your property... except a large and protective dog.

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#42
In reply to #26

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 2:55 PM

I used an SDR transceiver to record the rolling code from my car fob while out of distance of my car. I then played back the recording in range of my car and it opened the door. I could easily envision creating software that does exactly as described that would record and block a code from the fob and play back the second code to retain the first. You would only get one working code and would lose it the moment the fob is used without the hacking device operating. While one working code is all you need to get into a vehicle and is somewhat spy like, it is far from the easiest method.

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#43
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 3:45 PM

Correct, it is a hassle, and the rolljammer is a one shot deal - this shows that the concept and execution of rolling code technology works pretty well as designed. With the older system of dip switches, when the codegrabber does its job it will work until the switches are reset.

Thus the comment about a tire iron. Quick and easy to bust out a piece of door glass, or perhaps pry the door until the latch mechanism fails. A thief will do a thousand dollars of damage to your car, only to discover there is nothing inside worth stealing.

In the case of an automobile, an intruder has to be pretty swift lest he be discovered in his nefarious activity. Open up the garage door after the owner has left and a miscreant might enjoy a few hours of uninterrupted ‘alone time’ to explore the house.

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#22
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 4:08 PM

In other words ... We'll change the components, but not at our expense..

I've installed countless wireless entry components and I'm kinda wondering what new equipment might be in the hood.. Ive seen some strange things..

...I have a post to start about a new wft component installed nearby.. very interesting piece of kit as they say.

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#24
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 4:43 PM

Domotics is a hot ticket right now, lots of people seem willing (anxious even) to enable their homes to allow remote control of the lawn sprinkler, the motorized window shades, and the pet food dispenser.

Seems to me that lots of people wish that they were Inspector Gadget.

NFC is what some of the larger outfits seem to be pushing, as far as access token.

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#14
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 2:09 PM

The oldest garage door is 2006. That’s when the neighborhood went in. I did mean key fibs as in the keys to some older cars work outside the neighborhood, but not inside. Sorry for. E short answers. I’m on a break at work.

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#20
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 3:07 PM

So is it just American cars that the remote keys aren't working?

..."Keyless remotes contain a short-range radio transmitter, and must be within a certain range, usually 5–20 meters, of the car to work. When a button is pushed, it sends a coded signal by radio waves to a receiver unit in the car, which locks or unlocks the door. Most RKEs operate at a frequency of 315 MHz for North America-made cars and at 433.92 MHz for European, Japanese and Asian cars. Modern systems since the mid-1990s implement encryption as well as rotating entry codes to prevent car thieves from intercepting and spoofing the signal.[3] "...

These new radios could be interfering with the rolling codes ....

https://electronics.stackexchange.com/questions/85657/rolling-code-explanation

https://en.wikipedia.org/wiki/Remote_keyless_system

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#21
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 3:28 PM

If the codes are out of sync the key needs to be pressed twice to resync...unless the interference is continual....

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#25
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 4:46 PM

They make these RF analyzer apps... needs additional components...here's one

https://www.rtl-sdr.com/rf-analyzer-android-app-hackrf/

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#30
In reply to #20

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 7:43 PM

Here are some examples of the cars that are having issues

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#32
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 9:18 PM

The first thing I would try is pushing the remote multiple times at close range, this should work unless the interference is very strong and continuous....Then I would start shopping for alternate systems...

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#28

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 5:30 PM

If there are any amateur radio operators in the development, they should have access to the equipment to track the problem. Contact the ARRL, they can have a local amateur assist you. Have you called the manufacturer/installer? They too should be able to point you in the right direction. Last resort is to call the FCC, once upon a time that was there purpose for existence.

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#39
In reply to #28

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 9:53 AM

That’s a good idea. I’ll try and see if I can find one. The local news station is supposed to be coming out with some RF equipment too.

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#40
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 12:02 PM

Is a telephone call to either the Public Information or the Community Outreach officers at the airbase out of the question?

An official response from the originator of the interference may include recommended remedies or mitigation efforts, or perhaps advise that this is a temporary situation.

Additionally, think of the fun you can have ratting them out when the USAF denies having any idea what you are talking about!

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#33

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 10:54 PM

What about a signal repeater to boost power? Where would you mount this? On the garage door? In the car? Not bad if it works for $25.

I would be inclined to try this, maybe switch frequency too...First need to find what frequency is being jammed...

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#34
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/07/2018 11:48 PM

If you could get that to fit the key ring, I sort of doubt it would fit in your pants pocket.

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#35

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 12:13 AM

By any chance, did this happen on Elm Street?

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#36

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 7:07 AM

What do the car and keypad manufacturers and the FCC see as the reason for this issue.

The radio spectrum is heavily regularized and one can not on it's own decide to start using a certain frequency.

I'm especially concerned as we are in an evaluation phase of a wireless development that would use 434 MHz as center frequency. This is ISM and somehow the only near worldwide sub-GHz band that allows for miniaturized designs. (Only Japan does not allow emissions in this band)

If the US military somehow jams this ISM band for whatever reason they think is necessary, we are in trouble.

if it is indeed a band that is not for unlicensed use where the systems work in what used to be called noise level and the military decided to make full use of what is theirs, though shit for the system suppliers.

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#37

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 7:52 AM

This may help to work around your problem but you would want to find out what frequency it operates at. Although it was invented for motorcycles you can use it in any vehicle with a 12 volt system.

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#38

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 9:35 AM

I am going to recommend you contact you local university or even a community college and see if anyone is interested in a real world mystery to investigate.

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#41

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/08/2018 1:48 PM

Power Meter RFI and the Encoding Frequencies of Fobs

While key fob carrier may be in the 300-500 Mhz range, the signal encoding waveforms may be much lower frequencies. The power meter RFI link shows the power of noise coming from a smart meter here in Austin, TX on the home of a local military oscillator business owner who puts up a DIY website with lots of hobby circuits. The specific hobby circuit of the link involves VLF receiver circuits. The author shows a signal strength waveform plot which demonstrates that the radiated VLF noise from his power meter (on left of plot) is a higher strength signal than a local, powerful AM station (KLBJ 590khz on the right of plot). That is a lot of interference ! Given that a neighborhood may likely have a power meter on each house, the combined interference at the encoding frequencies could easily swamp out the demodulated signal inside key fobs. I am not an expert on what encoding frequencies are used by various models of fobs so maybe someone who is can comment on them and their likely harmonics and the plausibility of near or far field coupling into traces in the fob receivers carrying the demodulated signals.

The numerous yagi/SDR/foxhunting posts are excellent ideas especially if you include harmonic concepts and signal encoding frequency concepts in your sleuthing. Another idea which might easily bear fruit at these far lower frequencies is to open up a fob receiver and scope some trace normally connecting a demodulated signal to its decoding chip to see if noise is present there as opposed to the harder-to-scope-analyze multihundred megahertz traces. The fact that older fob receivers seem more vulnerable is interesting since new fobs may only have quite short on-chip traces carrying demodulated signals due to the economics of higher levels of integration in more modern devices. Be aware that detector diodes may detect the low frequency signals as well as the high ones making the antenna circuits in fob receivers into effective vlf near field loop receiver antennae.

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#44

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/09/2018 8:11 PM

Thanks for all the tips and and discussion. The neighborhood is back to normal after the news story ran. We still don’t know why it happened though.

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#45
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/09/2018 8:26 PM

Please, Jeremy, what news story?

We are a curious bunch... occupational entanglement.

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#47
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/11/2018 8:05 AM

Yes please don't leave us hanging!

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#48
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/11/2018 12:09 PM

Someone in the neighborhood called the local news channel and they came out and ran a short segment. They demonstrated the nonworking items and that was about it. I just wondered if someone in the area saw the report and realized what was going on. There was no resolution as to what was causing it. It remains unsolved ��

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#49
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/11/2018 1:33 PM

AARRGGHHHH!!!

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#50
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/12/2018 12:50 PM

Now that's what you call anticlimactic....

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#51
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/12/2018 1:21 PM

Just between you and me,... I heard that the Russians were behind it...

oh crap...

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#52

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/12/2018 3:29 PM

Maybe it was the UFO the DOD was tracking.

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#53

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/12/2018 3:34 PM

Is it the kind where you can change the battery?...

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#54
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Re: Entire Neighborhood Loses Garage Door/Key Fob Use

06/12/2018 5:06 PM

Yes, and they are also the type that has to accept interference from Land Based Military Radio signals.

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#55

Re: Entire Neighborhood Loses Garage Door/Key Fob Use

07/01/2018 8:22 AM

It sounds like the same problem seen here for many years in city areas, near to powerful radio transmitters. Ones not even anywhere close to the frequencies affected, but the signal is so strong, it simply blankets everything.

It might even be a new mobile phone antenna for example..

VW had a huge spate of cars not locking or not unlocking in the late 80s early 90s, I forget exactly when.

People came back to their cars and found the locks open, which caused a huge effort by VW to try and make better filters, to no useful effect.

The final fix, which is found in just about every modern car (that I have driven in the last 20 years or so) nowadays, is if the door is unlocked, but no door is opened within around 25 seconds, the door locks are reactivated.

As to if this relates to garage doors I cannot say, but a good test might be a) New batteries in the fob b) place the fob right next to the antenna and press the button and see if it then works when there is little distance between the fob and the mechanism.

But no guarantee.

This is of course no great practical help, but it might explain the reason for the problem.

Someone there should try and find out if some new transmitter has been installed/switched on recently!

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