[RFI] RFI With Smoke Detectors

[Jim Brown]

On Wed,8/19/2015 12:29 PM, Stan Zawrotny wrote:
> Frank,
>
>>> Does the interference to the smoke detectors occur at very low RF
>>> output...say 5 or 10 watts?  Or does it occur only AT higher output levels.
> It increases with power. Gets really bad when I kick in the linear.

What about 5-10 W?

>>> Have you attempted to contact the importer or manufacturer to inquire about
>>> the application of bypass caps to AC power lines or battery leads as well
>>> as other parts of the device to minimize the effect of RF on the chirp
>>> circuit?
> An email to the manufacturer, USI Electric Inc., went unanswered.

Have you considered the telephone?  Have you contacted the installing 
contractor?

> My antenna is an 80-6 meter OCF up about 40 feet in the trees. 

An OCF antenna is a recipe for LOTS of RF conducted onto the feedline 
and into your home.

> I don't think it is radiating back into the house.

I'm pretty certain that it IS.

> The house is ICF construction with a tin roof. I essentially live in a Faraday cage. I have to go outside to use my cell phone. The house will withstand a cat 5 hurricane or tornado.

The cell phone is UHF, your ham rig is HF.

That OCF antenna, by virtue of its imbalance, puts a LOT of common mode 
RF current on the feedline, which penetrates what you THINK is a Faraday 
cage (and it's NOT a Faraday cage unless the metal completely encloses 
the area you're trying to shield, AND all the metal parts continuously 
bonded together). And when you penetrate that structure with that 
feedline, it completely defeats any shielding that you think you have.

73, Jim K9YC