Hi Bill & greetings everyone:
>Bill Coleman wrote:
BC>I assume RFI is an antenna system problem...
It's bad to assume; however, I've also noticed more TVI problems with
verticals too! Maybe due to the lower angle of radiation or something.
Instead of most signal power going almost straight up, it's supposed to go
more out toward horizon theoretically with verticals.
RFI/TVI is a problem in selectivity of equipment receiving the interference in
my opinion. The equipment cannot distinguish between the signal it's suppose
to get and SIGNALS it's not suppose to. e.g. A telephone is suppose to
respond to audio and certain control/tone signals like ringer signalling. It
is not suppose to respond to RF in any way. If it does, it's a radio, not a
phone. There are certain phones which are "bullet proof" and do not pick up
interference when installed in place of one that does. This I think proves
the point: It's the phone! Or, specifically, the design of the phone.
BC>I'd like to help solve the problem, just to be neighborly.
It's nice to be neighborly, and unless you're good friends with them, be very
careful in helping out. Don't do any installation or modification of their
equipment. If their house burns down the next day, you could be liable or at
least dragged into a lawsuit. The only help I'd give neighbors who aren't
good friends is *advice*.
BC>Any suggestions? What is most effective?
BC>I've considered moving the R7000...
First suggestion: Get "Radio Frequency Interference: How to Find It and Fix
It" by the ARRL. It's a very good book on the subject and up to date.
Start with what's easy first. Figure out which equipment is most susceptible
and which equipment does not receive interference at all. If some equipment
does and some does not, it helps prove to the owner that it's his equipment,
not urs that's the root cause of the problem.
Next, add filtering to the susceptible equipment and test with the system
simplified i.e. all other phones/devices unplugged, etc...
Try toroid/bead ferrites on lines into/out-of equipment as close as possible
to the equipment (inside if possible). Look into K-Comm type filters for
telephones; they work sometimes to varying degrees. All of this is in the
ARRL book in detail.
Moving the antenna will help to a degree, but it's a lot of work to go through
for a few db of RFI attenuation. It might not even be a noticeable change to
the untrained non-ham ear. (Done That, Been There, Got the T-Shirt!)
BC>I did find the FCC CIB-10 bulletin...
The one I got directly from the FCC is:
CIB-2 Interference Handbook
It deals with Home Electronic Entertainment Equipment in general. Call the
FCC National Call Center at 1-800-418-FORM to order.
I just called & ordered CIB-10 which deals only with telephone RFI.
Tnx for the tip!
73,
de ed k0il
ARRL TS
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Eddie Jay Edwards E-mail: ejedwards@oppd.gov
P.O. Box 375 Amateur Radio Call: K0IL
Elkhorn, NE 68022-0375 AK-SAR-BEN ARC President, 1996
Visit Ak-Sar-Ben ARC home page at URL> http://www.probe.net/~aarc
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