Invisible dog fence causes RF interference
Brett Saylor
My neighbors have an Innotek Homefree HF-201 invisible dog fence system
installed, and the transmitter can be heard in my shack over 300 feet
away, causing interference to the LW and lower BCB bands. Apparently the
signal is getting into the power mains at their house and is rebroadcast
over a wide area. I can hear it on my portable, especially near and in
their house but also throughout the neighborhood, so I know it is not
entering my radios (only) through the power lines. They said their dog
gets shocked inside their house in their family room, and is afraid of
going near their TV. They were suprised by the level of signal inside
their house when I showed them how strong it was!
Is there any way to eliminate the signal getting into the mains, such as
using an RF choke or capacitor, at the source? The wall wart that powers
the transmitter appears to be a cheap import, and makes gobs of noise of
its own. When I wrapped the cord going from the power wart to the fence
tranmitter around my radio, the signal was overwhelming.
Thanks,
Brett
N3EVB
MR A MULDER
In article <3501B7...@psu.edu> Brett Saylor <bd...@psu.edu> writes:
>From: Brett Saylor <bd...@psu.edu>
>Subject: Invisible dog fence causes RF interference
>Date: Sat, 07 Mar 1998 16:07:22 -0500
>Thanks,
>Brett
>N3EVB
Get them to turn the thing off...and get rid of it. They should put up a
real fence to keep the dog inside the yard. When I see such things being
used I feel like putting that collar onto the "human" and let them suffer
like they make that poor dog to do.
Matt Gilbert
In article <psam.197...@giraffe.ru.ac.za>, ps...@giraffe.ru.ac.za says...
To skip to the meat of the article, go to the bottom, if you would like
to read my soap-box digression on wireless fences and dog training,read on.
Get a clue - the wireless fence is a TRAINING device, you teach the dog
to halt when it hears the TONE, if properly used the dog should only
get zapped once - that's when you actually teach it what happens when you
ignore the tone. A person who purchases the fence should walk thru the fence
at least once to experience what the dog will get - use this to determine
if the shock would cause more harm than good to your dog. People have been
using the tone/shock system to train dogs (especially hunting and police
dogs) forever. The training system of containment is much better than a
physical barrier (why? glad you asked) because very few neighborhood fence
systems will actually contain any able dog. Most dogs can jump a 4 foot fence
from a stance and a 6 foot fence on a run. Since you did not TRAIN your dog
to stay in the fence (why train the dog, that's what the fence is for) your
dog will hop that fence the first time it gets excited or scared or provoked.
But if you TRAINED your dog to stay within the tone, your dog is mentally
conditioned to remain in your yard, and this mental conditioning is
much more powerful than any fence you could put up in your backyard. My dog
will chase rabbits and squirrels across my yard at full run and stop just
short of the tone every time (one day I'm gonna turn that fence off and
just let her chase the shit out of those squirrels - boy won't they be
surprised - hi,hi ) Overall, a properly trained dog is a much happier and
safer dog than one that can run free - you will find that once you train
your dog to something, anything (fence, sit, stay, etc.) that further
training is that much easier. The key of any training methodology is that
both the training and devices must be used responsibly and with respect
for animal to be trained. The training is a two way street of both owner and
dog adapting to the needs of each other - anyone who refuses this is not
a good trainer and probably a worse owner. Those idiots who simply install
the fence and let the dog get zapped are complete buttheads and should be
placed on the end of a good HF amp running RTTY. An owner has a responsibility
to care for, love and nurture a dog. The dog will, in return, provide many
years of loyalty, companionship and joy. Properly training the dog is only
part of the owners responsibility to the dog (rubbing its belly and letting
it sleep on the bed are other responsibilities hi,hi).
Now back to your problem, you may want to check with your neighbor on
the installation. The device may not be properly grounded, if that checks
out, try powering the device with a battery, they usually use a wall wart
to get power so swap it with a batter. This will tell you if the noise is
being radiated and picked up that way or if it is coming into the AC wiring
thru the wall wart. Then you can combat either problem. If it is being
radiated, make sure the fence wire does not run parallel in close proximity
to an AC wire or maybe even just turn down the intensity of the fence.
If the wall wart is the problem, try a choke or maybe a filtered outlet.
I have an original Radio Fence, the device is grounded to a copper
pipe and the fence actually runs thru part of my basement no more than
15 feet from my gear, I have no problems. I suppose it is possible your
neighbor's unit is actually defective as well.
Matt Gilbert
KC8FAY
Brett Saylor
Matt Gilbert wrote:
> >>From: Brett Saylor <bd...@psu.edu>
> >>Subject: Invisible dog fence causes RF interference
> >
> >>My neighbors have an Innotek Homefree HF-201 invisible dog fence system
> >>installed, and the transmitter can be heard in my shack over 300 feet
> >>away, causing interference to the LW and lower BCB bands. Apparently the
<snip>
> Now back to your problem, you may want to check with your neighbor on
> the installation. The device may not be properly grounded, if that checks
> out, try powering the device with a battery, they usually use a wall wart
> to get power so swap it with a batter. This will tell you if the noise is
> being radiated and picked up that way or if it is coming into the AC wiring
> thru the wall wart. Then you can combat either problem. If it is being
> radiated, make sure the fence wire does not run parallel in close proximity
> to an AC wire or maybe even just turn down the intensity of the fence.
> If the wall wart is the problem, try a choke or maybe a filtered outlet.
> I have an original Radio Fence, the device is grounded to a copper
> pipe and the fence actually runs thru part of my basement no more than
> 15 feet from my gear, I have no problems. I suppose it is possible your
> neighbor's unit is actually defective as well.
>
> Matt Gilbert
> KC8FAY
I tried wrapping the power cord from the wall wart around a ferrite
core, and this reduced the interference by about 50%; someone wrote
suggesting a ferrite rod would be even better, but I haven't tried this
yet. My next step was to buy Radio Shack's AC line filter, but I haven't
had the chance to install this on the power supply yet. I'm hoping these
two things will reduce the noise to a reasonable level. The power level
is at near minimum, and can't be turned down much more. For some reason,
they bought the super-duper *25 acre* version (even thought they have
less than 1 acre!) so even at it's minimum, it's likely to be far more
powerful than necessary.
I suspect that the fence may run parallel to their power main for at
least a few feet, as it is located close to where the power meter comes
into the house. I'm not sure that it will be easy to relocate the
antenna. But, I'll keep trying to solve this one!
Thanks for the suggestions,
Brett
N3EVB