On 2014-05-09, Jim Thompson wrote:

First, try a simple experiment. Open the garage door wide and test
the range of your unspecified model garage door opener radio. If you
get normal ranges (200ft or more), then the problem is the garage door
shielding. However, if the range is the same, the tuning on either
the transmitter or receiver is off frequency.

Dramatic range improvement.

that confirms it's a "antenna in a metal box" problem

How about this... Drill hole in door, fit water-tight thru-hole BNC
connector, attach rubber ducky antennas to each side. Would that be
enough of a "window"?

I'm thinking that be the eqivalent of about a 4" window in your door.


It'd work better if the indoor antenna was closer to the receiver.
I'd be considering putting the indoor antenna in the near field of
the receiver antenna. (but only after rejecting a direct connection to
the receiver circuit)


You've got inverse square law losses between you and the outdoor
antenna and again between the indooor antenna and the receiver.


Moving the indoor end of your passive repeater to where it does most
good has got to be good for a 30db reduction in loss.

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umop apisdn