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Author Topic: Garage Door Opener Damaged by HF RF?  (Read 868 times)

Offline ultravista

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Garage Door Opener Damaged by HF RF?
« on: December 11, 2022, 0123 UTC »
Yeah, this is a crazy one.

My wife's garage door opener stopped working yesterday. I replaced the battery and it works when very close to the garage door receiver, like underneath.

Today, my son tells me his garage door opener isn't working. His is 2 weeks old and opens a different door (not the same as my wife). It works when you elevate it to the window and a few feet from the receiver.

So I tested mine, the same door as my son, and it took has a extremely limited range. I could not open the door unless I held the opener up high @ the window.

Previously, we could open the door at the top of the driveway, at least 30 feet away. Now, unless it is in line-of-sight with the receiver, the receiver doesn't receive.

The only thing different is my operating an end-fed @ 100 watts on 40 meters. Prior to my operating @ 40 meters, the garage door receiver had a decent +30 foot range. Now, it's practically deaf.

The low receive occurs when not transmitting, like tonight, when we went out to eat. This is when my son told me his door opener doesn't work.

So ... did my amateur radio operation permanently damage the garage door receivers?

Offline ~SIGINT~

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Re: Garage Door Opener Damaged by HF RF?
« Reply #1 on: December 11, 2022, 0218 UTC »
Hummm, anything is possible but I find it hard to believe that the receivers would have been damaged by HF operations. It would be interesting to know what frequency these operate on. There is a good chance that you will find that the garage door openers are in the high 400 plus MHz range, far from HF.

Disconnect all of them then just try one at a time to see if they may be interfering with each other. If you can find out the frequency they operate on you can also watch / listen for them on an appropriate receiver. This is what I did after I moved. I had misplaced the remote outdoor sensor for my weather station and in order to find which box and its whereabouts I just used my ICOM IC-705, tuned to the frequency and sniffed it out as it beaconed away. You can test the garage door remotes in the same way.

Offline ultravista

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Re: Garage Door Opener Damaged by HF RF?
« Reply #2 on: December 11, 2022, 0342 UTC »
The garage door openers are Chamberlain, both operate w/a different remote. I do have LEDs in the garage and they have been there for at least a year. Prior to a few days ago, regardless if the garage LEDs were on or off, the garage doors operated from 30+ feet. Today, the range is underneath the garage door opener (receiver).

The environment is the same - the only thing new is my transmitting @ 100w from an end-fed antenna.

It doesn't make sense that the garage door receivers would be permanently affected, but something has rendered them practically useless.

My third remote opener is only a few weeks old. The battery is new and the 'transmit' LEDs on the remote are bright. I have to put it up in the air by the garage door window to open the door. The receiver antenna is visible - straight down as it always has been. The same applies for the other opener.

Offline radiogaga

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Re: Garage Door Opener Damaged by HF RF?
« Reply #3 on: December 11, 2022, 0530 UTC »
How close is the 40 meter transmit antenna to the opener receivers?

rgg

Offline NJQA

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Re: Garage Door Opener Damaged by HF RF?
« Reply #4 on: December 11, 2022, 1410 UTC »
We had a number of locals suddenly have problems with their garage door openers.  The problem turned out to be a new trunked radio installation at a nearby government base.  The local hams were able to verify that the new system was up and running by using SDR receivers.  The local press picked up the story.

As I remember, the garage door openers that were impacted were using frequencies in the 300 MHz band as secondary users.  The government was primary, but agreed to delay going operational with the new system for a short time to give homeowners a chance to modify their door openers.  Amazon sells new receivers to retrofit older openers.

Considering how this problem suddenly impacted everyone, RFI seems a likely cause.

https://www.insidenova.com/headlines/top-secret-government-center-admits-interference-with-fauquier-garage-door-openers/article_b09dd948-0116-11ea-b4d6-db45151e2c1c.html

https://www.creativedoor.com/blog/troubleshooting-garage-opener-remote-range-and-interference-issues


« Last Edit: December 11, 2022, 1425 UTC by NJQA »

Offline redhat

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Re: Garage Door Opener Damaged by HF RF?
« Reply #5 on: December 11, 2022, 1438 UTC »
Fwiw, I've had rf from my test transmitter at the house kill cheap led bulbs....

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Offline NJQA

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Re: Garage Door Opener Damaged by HF RF?
« Reply #6 on: December 11, 2022, 1559 UTC »
Testing this should be easy enough.  Look at your garage door receiver to see what the operating frequency is.  Use a SDR like a RTL or a RSP and examine the spectrum near that frequency, looking for strong signals. 

If you donít know the door opener frequency, look at the entire spectrum from 300 to 400 MHz.  Most garage door openers seem to operate in this range.

If the problem is there all the time,  an interfering signal would be there all the time, like a LMR repeater.  It would be pretty strong to override your car remote.

Around here we have Government trunk radio systems in the 380 MHz frequency range.

Offline ~SIGINT~

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Re: Garage Door Opener Damaged by HF RF?
« Reply #7 on: December 11, 2022, 1651 UTC »
A quick Google search revealed that:

Quote
The Frequency of the Chamberlain Garage Door Opener Since 2005, Chamberlain, as well as a number of manufacturers, have changed their radio frequency to 315 MHz.

The reason is that the garage door openers must match the U.S Department of Defense and the department of homeland security already use the 390 MHz to control the LMR system.

You will need to determine what frequency your garage door openers operate on.

Offline ultravista

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Re: Garage Door Opener Damaged by HF RF?
« Reply #8 on: December 11, 2022, 1806 UTC »
How close is the 40 meter transmit antenna to the opener receivers?

rgg
On the deck. The coax runs 20 feet to the unun. If counting the height, about 30 feet.

Offline ultravista

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Re: Garage Door Opener Damaged by HF RF?
« Reply #9 on: December 11, 2022, 1807 UTC »
I have not replaced anything in the house for a while, no new electronics, nothing new at all.

This is very strange. I understand that some devices may act-up when transmitting, but my two door openers are practically deaf now. I bought new batteries today and the door won't open unless the remote opener is a few feet from the receiver. The wire buttons of course open/close the door perfectly.

Last night when we returned home, the garage door bulbs were off, the garage was dark, and it still wouldn't open - I waived the remote around in the air with the button pressed and it eventually opened.

On a perhaps related note, my Vizio soundbar mysteriously died Friday night while watching a movie. It is dead. I opened it and didn't see any blown/bulging capacitors. Googling the problem, I see many others have similar problems with the Vizio soundbars crapping out after a few years. It is coincidental that the garage door openers and soundbar are both affected the same day.

I was not transmitting when the soundbar died - the radio was off and we were watching a movie.

As I lead-off, very strange.

Could the front-end of the garage door receiver be damaged? I presume it either works or doesn't work. It doesn't make sense that it works but only when the opener is a few feet from the receiver.

Offline ~SIGINT~

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Re: Garage Door Opener Damaged by HF RF?
« Reply #10 on: December 11, 2022, 2144 UTC »
Without a schematic of the receiver it might be hard to tell. One has to think that it was designed with a band pass filter on the input so theoretically, HF shouldn't even get past the filter if that was the case.

Again, some kind of receiver with a spectrum / waterfall display would be of great help to you in troubleshooting the signal.

Maybe you got hit with some really bad AC line spike.
« Last Edit: December 11, 2022, 2214 UTC by ~SIGINT~ »

Offline redhat

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Re: Garage Door Opener Damaged by HF RF?
« Reply #11 on: December 11, 2022, 2225 UTC »
Interference is more likely than damage.  Get an SDR or spectrum analyzer and see if there is anything strong near (or a sub-multiple of) the frequency of operation.  Once upon a time, I had an FM pirate on the roof of a house in suburbia.  Whenever the transmitter was on, the garage door remote wouldn't open the door.  I did some measurements and found out that the 3rd harmonic of the commercial transmitter was a little high.  I put a quarter wave stub on the transmitter and the garage door went back to normal.

I have had HF mess up microprocessor based things, but they usually don't work again until you power cycle them.

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Offline ~SIGINT~

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Re: Garage Door Opener Damaged by HF RF?
« Reply #12 on: December 11, 2022, 2349 UTC »
Even a new appliance, computer, wall wart, switching power supply etc ... could be the culprit.

Have a look at this piece of nastiness floating around my house. Guaranteed to cause interference, and some day I will take the ICOM IC-705 with the sensing loop antenna that I built and go RFI / EMI hunting.



Of course, there is always the brute force method of troubleshooting. Turn all the breakers off in the house for the exception of the one for the garage door opener and see what happens. If it starts to work again, the issue is local. Start powering up the house one breaker at a time until you find and isolate the culprit.
« Last Edit: December 12, 2022, 0204 UTC by ~SIGINT~ »

Offline Brian

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Re: Garage Door Opener Damaged by HF RF?
« Reply #13 on: December 12, 2022, 1344 UTC »
RF can do the strangest things. I used to run a 1 Kw MW transmitter the odd time. One time, I switched it on and ran some music. The audio on my radio was sounding very strange. Like someone was jamming me with an unmodulated carrier. I went for a walk and the "jamming" decreased the further away from the house I went.
It turned out an energy saver light bulb (probably LED) I had recently installed was picking up the signal and re-radiating it on the same frequency around the house  ???
« Last Edit: December 12, 2022, 1345 UTC by Brian »

Offline Charlie_Dont_Surf

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Re: Garage Door Opener Damaged by HF RF?
« Reply #14 on: December 17, 2022, 0623 UTC »
Yeah, all good recommendations.

I agree that it is more likely interference than damage to the garage door receiver. If it was strong enough to damage then your clock radio, your remote weather station receiver, etc. might have been damaged as well.

Yes, 315 MHz is likely the frequency. Mine (from a different company) works there too.

I'm going to suggest a few things:

1) I think that Brian might be heading down the right path. Did you install any new electronic gizmos or any new LED light bulbs, etc. in and around the house (not necessarily restricted to the garage)? How close is your garage to any neighbors, (who might have some new gizmos)?

One way to do a real brute force interference check (and annoy the rest of the family) is to kill the power to everything else in the house and garage simultaneously except the garage door opener, then try the same check with your garage door remote. If there is joy, you can do a process of elimination to figure out what is happening. You can also disconnect stuff like your Ham rig coax, sprinkler system power, your dog's invisible fence, etc. The reason is that all manner of weird stuff can be causing interference. [EDIT Sorry - already suggested.]

2) Are you completely sure that the garage door receiver antenna has not changed position and placement at all? On mine, the antenna is a piece of wire about 12" long hanging from the motor unit. Here's a crazy idea: make it longer or shorter (like dramatically, 2x or 3x). What happens?
I don't STRETCH the truth.

"Every minute I spend in this room, my signal gets weaker.
Every minute Charlie squats in the bush, his signal gets stronger."

 

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