> ...
> I noticed on the transponder antenna installation instructions the
cryptic
> warning " do not mount within 5' of occupants'...
I think the problem is the worst-case assumptions they need to make,
then in-house counsel add a foot ; then outside counsel doubles the
result!
In addition to making no assumption as to how much power loss in your
coax and your actual power output vs. the minimum specification, the
safe distance is very much a function of how often ATC (and lately
TCAS-equipped planes) are interrogating you. Then you need to assume
all data bits are being sent (rare), plus an ephemeral ident bit even.
The ARRL (ham radio types) has an online safety calculator, and
realistic assumptions do result in inches of safe distance at even 2
interrogations per second.
Reg,
Fred F.
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