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Comment by jonhohle | Hacker News Reader

When it’s sunny, my wife’s car can’t open the garage door, and my car requires getting extremely close. Once the sun goes down, we can both open the door from the street.

It turns out our solar panels (or the optimizers, or the inverter) emit radio frequencies that interfere with our garage door opener. When the sun is out and they are producing energy, the interference is stronger than the homelink garage door opener.

A few years ago the garage door openers started working fine. It took a few days to realize it was because the inverter had failed.

I’m fairly certain there are some FCC regulations that would require our installer to fix it, but that relationship soured during installation and I’d rather deal with an unusable garage remote than dealing with them for warranty work.

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Some clip on ferrites on the inverter cables might help.

If you have any amateur radio neighbours they'd probably love to help you with a project like this.

If they had a HAM in direct neighborhood, I imagine said HAM would already pay them a visit - the interference from the inverter is likely not constrained to the ISM band.

Not to be a pedant, but just for your info, Ham is not an acronym :)

I always saw it written as either "HAM" or "ham", and I assumed the latter is the "young generation doesn't give a damn about spelling or punctuation" spelling, and therefore that the former is the correct one.

On the cables coming in from the panels or wiring going back to the main panel?

I'd start with the wiring going back to the main panel first but be open to anything. Fixing RF noise is more of an art than science in my experience.

If you get a SDR, you can watch the interference and try things to help reduce it. An SDR should be like $20 and you plug it into a computer

Just curious but did you try any bodged shielding?

I used a coax cable to move the antenna closer to the exterior wall and didn’t see an improvement, however, I might not have grounded the shielding properly. I’ve had to replace the control board since then and didn’t replace the antenna on the new board, but may try that again.

How old is the garage door opener? Older ones used frequencies that are more susceptible to interference from certain sources. It's possible to buy new receivers to connect to your existing door opener.

The garage door openers aren’t terribly old, but they are terrible!

I have a HomeKit opener attached to it that we use during the day. Fortunately that’s been reliable enough to get around the issue.

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