Wireless overhead door opener and RF interference

I have a problem that I would like the groups's suggestions for help.
 
My detached garage has three overhead doors made by Liftmaster. These doors have the standard wireless remote control and also a wireless 60 watt light that goes on when the door opens. The light can be plugged into any AC outlet to p[ower the bulb and then receives it's on/off signal wirelessly from the door motor each time it is activated.
 
The problem is that the lights were not switching on and off with the door and after much testing I decided that there was RF interference in the  garage causing the comm problem between the door motor and the light. More testing convinced me that it was two Netgear ethernet switches causing the interference. I disconnect the switches and the lights work.
 
Now this became a moot point when I installed UPB switches in the garage for the lighting but today my wireless remote control for the door started giving me trouble. The first thing I did was check the two batteries in it and sure enough they were weak (2.9v) each. With new batteries now it has the same problem so I tried unplugging the ethernet switches and sure enough the remote works well now.
 
So my questions:
 
Has anyone dealt with this in the past?
 
Can the antenna on the remote be improved? I think that holding the remote in your hand improves it's antenna but this is mounted on the wall.
 
Do you think that putting the switches in a metal box would help?
 
I don't like to spend on new switches but do you think that another may be better shielded?
 
Any other suggestions?
 
Mike.

Here I have two GDO's which are Liftmaster which are over 10 years old now.  The GDO remotes are built in to the auto mobiles and are all Homelink.  Here there is one 60 watt fore and aft lamp.  The whole set up is integrated similarly to yours except I go to the OmniPro 2 panel and UPB lighting.  Over the years added more lighting such that the garage is daylight whenever you enter it via the house or the garage door.  The garage is attached to the home.
 
I had an issue here and blamed it on my wife's RF sinking the GDO RF.  The garage doors would always open for me in whatever car and maybe 80% of the time for my wife in the same cars and same positions.  We did also test using the original Liftmaster GDO's with the results. (wife and I).
 
Here I googled extending the range on the two GDO's and found some DIY relating to using a straw over the wire such that the RF wire went vertically up.  I did the DIY fix and it seemed to work as I have not had any more issues issues.  It is not an extension to the antenna rather just a reposition of it.   The Homelink devices are integrated in to the visor or centre dome lamp.  I did read some about tweaking the range on the Homelink devices using tin foil inside of the device.  Been playing with Active RFID which works well but not using it to open garage door today.
 
I have never read about Ethernet switches causing garage door remote problems.  Here installed a hotel style POE in wall AP / Switch which has never caused me issues.  I also have a couple of those 3Com / HP in wall mini POE switches which are managed switches which work fine today.
 
You can check for RF noise with and old portable AM radio.  Just put it near the switches.
 
I have had RF/audio noisy power supplies.  I replaced them.  Maybe trying another power supply?

I'll give the AM radio a try, I don't know the freq of the door remote but maybe I can find out from linksys. As for power supplies I don't have anything in the garage. The only elk equipment there is an input adapter, an output adapter and a data hub. That equipment gets power from a power supply up in the house.
 
I can't extend the antenna upwards because they exit the bottom of the door motor. It is a jackshaft type motor that is mounted to the end of the shaft with the pulleys at the top t of he door track. The door tracks go straight up the wall about 20' like in a gas station and the motors and antenna  are at the top.
 
Mike.

Yup the Liftmaster remote control frequency is 390Mhz and uses a rotating code.  The stuff from the Linksys whether the device or power supply would generate RF harmonics if anything.  So it sounds like it is generating RF noise from the switch itself.
 
Yup here the terminals / antennas are next to each other in the back of the GDO motor.  Yours description sounds like there is no issue with height.
 
Here it's a tiny antenna and putting it in the straw just made it vertical.  Thinking I just taped the straw to the back of the GDO.
 
 

mikefamig said:

I don't know the freq of the door remote but maybe I can find out from linksys.

Click to expand...

 
This chart might help. Some are 390 MHz, others are 310 or 315 MHz.
 
https://www.liftmaster.com/Catalogresourcesv3/en-us/shared/files/generaldocuments/375UTAccessoryCompatibilityChart.pdf
 
It's puzzling why the ethernet switches would be generating noise in that frequency range, but I guess anything is possible. Might even be a bad switching power supply rather than the switch itself.
 
Are the switches located in the garage, or in the house?

Here along with that garage door frequency the RFID stuff is at 350Mhz and the remote W800 working at 310Mhz and I think too there are other things floating about the house in that 300Mhz range. 
 
I looked at my little GDO straw gizmos and I did extend them with a piece of thread. 
 
I am assuming from Mike's description that the switches are in the garage and the power supplies for the switches are in the house.

The switches are in the garage with the door openers. There is an 8 port switch in the front of the building that serves a couple of cameras and then a cable to the back of the building where there is a 5 port switch for a pc and a TV set top box. It's my man cave.
 
I can't think of what else can cause the interference. I have AC outlets, fluorescent and LED lights, an AVR/television and the alarm system components and two foscam cameras.
 
I blame the switches because the remotes work when I turn the switches off. It just occurred to me that there is also a Bosch motion detector that I haven't thought of in the past. Could that be a problem?
 
Mike.

Here's a reference to video cameras interfering with door openers
 
http://foscam.us/forum/garage-door-opener-interference-t1332.html
 
The cameras are both wired but it's worth a shot. Maybe their pwoer supplies are noisy?
 
Mike.

Is there an inexpensive device that can be used to hear noise in the 300mhz range?

Pete
 
You mentioned using an AM radio to hear the interference. I know that it will amplify AC 60hz buzz but will it receive in the 300 mhz freq range?
 
Mike.

Well here I do not remember when I used that AM radio for noise checking.  I used it originally for the carpc stuff and the audio bleed over noise (which partially was due to the alternator and power supply I used on the carpc).
 
Today I do have a old portable radio with AM/FM/shortwave bands.  I only really used the shortwave stuff when I used to travel internationally.  It worked really well and it was like a miniature old Zenith Trans-Oceanic radio.
 
That said a tornado will also generate much RF noise / harmonics over a wide spectrum of frequencies.
 
Today you can build yourself a widget.  I am using one today for NOAA satellite stuff.
 
Purchase a little cheapo EU TV tuner USB stick thing (DVB-T tuner) from Ebay for around $7 and download SDR radio software which you can run on your laptop.  Set up a scan for the frequencies in question.  You will see the stuff visually and hear it.  It is just software and the tuner has all of the guts to do this today.
 
It is inexpensive to do this and just a bit time consuming. 
 
See here.  Listening to all of this stuff and watching it is mesmerizing. 

Pete
 
WOW I just looked at your link to the SDR stuff and there's another hobby that I'd like to play with but a can of worms that I don't want to open right now. I never heard of SDR...very neat. I've long thought that some day I'd like to get a small weather station for the house too but I already have too many hobbies distracting me from day to day obligations.
 
With all of the time that I spend on hobbies and toys I sometimes think that I should spend some of my time doing something to better myself like learning a second language or to play a musical instrument but I always end up back at the computer techy stuff or in the garage. I guess it's like they say....ya gotta love it.
 
Mike.

Start with the baby steps Mike.
 
You know that if you disconnect the Netgear switch the GDO remote works so the assumption is some sort of noise from the Netgear switch.
 
It is either the power supply for the switch or the switch.  I am not sure what powers the switch.  Here my managed 24 port switches have built in power supplies.  Other older smaller switches use external bricks.
 
It is these old bricks here that can cause RF noise.
 
Here now you can either narrow down the scope of the Netgear noise or up the range of the remote GDO.  Either should work. 

pete_c said:

Start with the baby steps Mike.
 
You know that if you disconnect the Netgear switch the GDO remote works so the assumption is some sort of noise from the Netgear switch.
 
It is either the power supply for the switch or the switch.  I am not sure what powers the switch.  Here my managed 24 port switches have built in power supplies.  Other older smaller switches use external bricks.
 
It is these old bricks here that can cause RF noise.
 
Here now you can either narrow down the scope of the Netgear noise or up the range of the remote GDO.  Either should work. 

Click to expand...

 
The IP switches have wall warts. I'll spend some time out there today and be a little more methodical in my testing than in the past and I'll be back with what I find.
 
You kind of got me on the hook with that SDR tech. I'll bet that it's very interesting to see all of what's available all around us that we are deaf and blind to.
 
Mike.

Now I'm thinking maybe I have a ground loop noise to the motors from a poorly grounded device like the wall warts on the cameras.
 
Mike.
 
EDIT
I should have said from the wall warts on the cameras and IP switches.