The AM Forum
July 23, 2024, 12:55:34 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Electric Fence, any quiet ones  (Read 6033 times)
0 Members and 1 Guest are viewing this topic.
K6JEK
Contributing
Member
*
Offline Offline

Posts: 1188


RF in the shack


« on: May 11, 2005, 09:27:47 PM »

One of my ragchewing buddies is plagued by electric fence noise.  He talked with the owner, a salty old rancher, who invited him to "have at it."  He discovered that the fence charger is an ancient gizmo that keys an inductor with a sparky old relay from a 12V battery.

My friend is inclined to just buy a new fence charger for the rancher.  But which one?  Any experience?  

Jon
Logged
W1EUJ
Guest
« Reply #1 on: May 12, 2005, 08:07:09 AM »

He could replace the supply with a HV DC-DC type, like those used for lasers. I have this little black 'hockeypuck' power supply that turns 120V to a couple of kV.
Logged
WA1GFZ
Member

Offline Offline

Posts: 11151



« Reply #2 on: May 12, 2005, 10:13:31 AM »

Try a T section filter on the output leads to decrease the rise and fall time of the pulse. The box will have to be well shielded to reduce radiation.
There is an old EMI test called the chattering relay. A relay set up as a buzzer. it would produce 600 volts with the relay coil as the inductor.
Reducing the slope of the signal would reduce the frequency component.
This will also reduce the voltage so you might roll up a cow and see if it still jumps after you are done. (so the rancher doesn't shoot you for letting his cows out. )
Logged
Todd, KA1KAQ
Administrator
Member

Offline Offline

Posts: 4244


AMbassador


« Reply #3 on: May 12, 2005, 02:59:19 PM »

I used to get my dad's fencer to be really quiet by unplugging it when I wanted to operate. No breakouts during that timeframe (it was usually at night), so I was lucky.

That particular one was a new unit in the 80s, completely encased in a metal cabinet. Didn't make a bit of difference. With a radiator as spread out as a fence, it's going to be difficult to cure even a small signal.

How about those furnace oil burners? Mine wipes out HF whenever it comes on, for as long as it's on, and it was installed new around 90/91.
Logged

known as The Voice of Vermont in a previous life
WA1GFZ
Member

Offline Offline

Posts: 11151



« Reply #4 on: May 12, 2005, 04:00:48 PM »

burn coal to fix the opec monster.
Logged
wavebourn
Guest
« Reply #5 on: May 14, 2005, 04:20:22 AM »

If you want the best electric fencing go for it to South Africa. They are widely used and highly developed there.

For example,

http://www.tandemsecurity.co.za/electricfences.html



http://www.easyinfo.co.za/getcategory.php?linkcode=3856&province=0&catSearch=Electric%20Fencing
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.142 seconds with 19 queries.