This is a weird one so bear with me.

I installed a remote starter in my car about 2 years ago. It will decide to ignore the key fob commands at random. It will last for a few days and then be fine again. Over time I began to realize that this was only occurring in my driveway.

Recently I installed a new garage door opener. The opener comes with this nifty light fixture that you plug into any outlet in the garage. It receives its on/off commands from the motor housing. It worked fine for a few days and then stopped working. Not putting 2+2 together I demanded a replacement fixture from the manufacturer. Then the light went on (in my head, pun intended). That light fixture stopped working the same day my remote starter stopped working.

I did some investigation and it turns out both operate at 433 Mhz. I also found that if I move the light so that its receiver antenna is close enough to almost touch the transmitter it will work. Get a few inches away and it doesn’t work. Ditto with the car remote. If I put the key fob right up against the antenna wire it will work. Otherwise no dice. I’ve confirmed that they are not interfering with each other.

So I have a few questions:

1) What sort of everyday (or non-everyday) device could be transmitting strong enough to cancel out my other 433 Mhz devices?

2) What’s a typical range of a 433 Mhz signal?

I did some experimentation and my car remote begins to function once I’m about 200 feet away from my house. Further experimentation seems to point to the interference coming from me or the people across the street from me. Being a gadget-type person I suspect I’m the cause of my own problems.

Any ideas?

Source: 433 Mhz interference – causes? – DoItYourself.com Community Forums