On Wed, 28 Apr 2010 21:52:43 -0400, Gary Hoffman wrote:
>I have to say that the mere existance of a "pin one problem" (sic) is
>neither a necessary nor a sufficient condition for
>having Radio Frequency Interference (or even hum on the signal) in the
>shack.
Of course. But when we transmit into antennas that are physically close
to our equipment, or to our neighbor's stereo, or his computer, there
can often be fairly significant levels of RF current on interconnecting
cables (and on the wiring of unshielded equipment. Heck, I just answered
an email yesterday helping a guy with RFI into a Kidde security system.
He was running 100W into an attic antenna, and setting off their smoke
alarms. That's far from an ideal antenna, but an increasing number of
hams are stuck with that kind of antenna, thanks to restrictions of
"planned communities" that prohibit outdoor antennas.
With that kind of proximity, it is just plain stupid to do something
that often couples RF into equipment, where any semiconductor junction
can detect it. And when you're building ham gear, it is a GIVEN that
there will be transmitting antennas nearby.
73,
Jim K9YC
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|