Actually most electric fences, even if there is no arcing, do generate a
broadband click every time the fence is charged. This happens because in most
chargers made in the USA there is no wave shaping and the pulse rise time is
very fast, creating a broadband signal. Some European models, I am told, do
have wave shaping and do not click in the HF bands. I'd like to find them in
the USA. Of course it is true that if there is a short or arc, the noise will
be even worse. But a new perfectly installed fence can be detected at close
range (e.g. under 200 yards).
Thus the solution is to either modify the charger to add wave shaping, or
filter the HF and MF components of the signal before it gets to the fence wire.
I have used a series tuned LC circuit at the output of a charger (tuned for
160)with success. A LP filter arrangement should also work.
I have asked before if anyone here knows a model number from Europe perhaps
that has built in wave shaping. Maybe someone can offer some wisdom. Bob N7UA
BTW another important point is to make sure that the fence has a good ground.
----- Original Message -----
From: Hardy Landskov <n7rt@cox.net>
To: k3lr@k3lr.com, 'RFI' <rfi@contesting.com>, mike@rfiservices.com
Sent: Mon, 5 Jan 2009 15:17:34 -0500 (EST)
Subject: Re: [RFI] A RF Quiet Electric Fencer needed
Tim,
I had a neighbor that had an electric fence that was arcing to a tree trunk.
But once we solved that problem, the fence was quiet. Are you sure you just
don't have an arcing problem somewhere along the fence line? I don't think
electric fences are noisey until they start arcing over to something but I
could be wrong. I do not know all styles or designs of electric fences.
73 & HNY N7RT
----- Original Message -----
From: "Tim Duffy K3LR" <k3lr@k3lr.com>
To: "'RFI'" <rfi@contesting.com>; <mike@rfiservices.com>
Sent: Monday, January 05, 2009 10:29 AM
Subject: [RFI] A RF Quiet Electric Fencer needed
>I need to offer a ready made solution to a nearby "Ticking" electric fence
> owner.
>
>
>
> Does anyone have a manufacture/ model number for an electric fencer that
> is
> RF spectrum (1.8 to 52 MHz) "Tic" free?
>
>
>
> Happy New Year and 73!
>
> Tim K3LR
>
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|