Home Intercom systems - possible source of RFI
 

For several years there have been annoying carriers on the SW bands at my
location - one of which was parked on top of WWV 10MHz. I recently decided
to track down some various RFI noise and discovered that my home intercom
system was the culprit. The one I have includes an AM/FM receiver and I
think it's the FM section putting out a carrier on or about 10MHz.

Hope this helps someone with similar troubles.

"DesignGuy" ) writes:
For several years there have been annoying carriers on the SW bands at my
location - one of which was parked on top of WWV 10MHz. I recently decided
to track down some various RFI noise and discovered that my home intercom
system was the culprit. The one I have includes an AM/FM receiver and I
think it's the FM section putting out a carrier on or about 10MHz.

Hope this helps someone with similar troubles.



How are the intercom stations connected? There's the obvious wire, but
at lest some use signals in the hundreds of KHz range. The signal is
impressed on the house wiring, and while much of the signal will be limited
to the AC line, obviously some of the weak signal can radiate.

Michael

"Michael Black" wrote in message
...

"DesignGuy" ) writes:
For several years there have been annoying carriers on the SW bands at
my
location - one of which was parked on top of WWV 10MHz. I recently
decided
to track down some various RFI noise and discovered that my home
intercom
system was the culprit. The one I have includes an AM/FM receiver and I
think it's the FM section putting out a carrier on or about 10MHz.

Hope this helps someone with similar troubles.



How are the intercom stations connected? There's the obvious wire, but
at lest some use signals in the hundreds of KHz range. The signal is
impressed on the house wiring, and while much of the signal will be
limited
to the AC line, obviously some of the weak signal can radiate.


Sorry, forgot to mention this is a *wired* intercom, built in the walls of
the house. Not like the kind that plug in a run over the AC lines.

I would scrap the wired intercom and get one of those new 5.8GHz cordless
phone systems with multiple handsets. With some of those new sets you can
page individual handsets from any other handset or a system wide intercom
page. I use the AT&T 5840 base with 4 additional 5800 handsets and it works
like a charm.