Fixing an invisible fence break with a RF choke

[wacki]

We have a break in the invisible dog fence that I'm trying to fix. I found this on the intranetz:

http://blog.paulasgriffith.com/2007/03/

Method #2: This method requires you purchase an "RF-Choke" from Radio
Shack (Catalog item # 273-102) and use an AM Radio. Once you have these,
follow these procedures:

1. Disconnect the boundary wire from the terminals on the transmitter.

2. Wrap the boundary wire around the choke leads

3. Connect the choke leads to the terminals on the transmitter. The
choke has now completed the loop as far as the transmitter is
concerned.

4. Turn the range adjustment knob up 1/4 to 1/2 turn.

5. Take the transistor radio and set it to AM 600. Stand outside the
structure where the twisted wire exits and listen for the
pulsating static of the transmitter.

Gently swing the radio back and forth across the front of your body and
follow the wire out to where the loop begins. Pick either direction and
continue until the pulsating stops for a 4-6 ft area. In this area is
your break.

That's what we did. We got pretty good at it!

I bought an RF choke #273-102 which is 100 microhenries +-10%, 2amps max, rated at 1kHz. I unplugged the boundary/fence wires from the transmitter and put one lead from the choke in one terminal/plug and put the other RF choke lead into the other terminal that used to grab onto the boundary/fence wire. I then took the boundary/fence wire and connected it to a lead of the choke. After tuning my radio to 600 AM and I got nothing.

Any ideas what I'm doing wrong?

 

[wacki]

x

 

[wacki]

Here is a graphic so there is no misunderstanding. The black and gold device is the RF choke. The green box is the invisible fence. The red line is the broken fence wire


http://img247.imageshack.us/my...=invisiblefencecf2.jpg

 

[Analog]

Originally posted by: wacki
We have a break in the invisible dog fence that I'm trying to fix. I found this on the intranetz:

http://blog.paulasgriffith.com/2007/03/

Method #2: This method requires you purchase an "RF-Choke" from Radio
Shack (Catalog item # 273-102) and use an AM Radio. Once you have these,
follow these procedures:

1. Disconnect the boundary wire from the terminals on the transmitter.

2. Wrap the boundary wire around the choke leads

3. Connect the choke leads to the terminals on the transmitter. The
choke has now completed the loop as far as the transmitter is
concerned.

4. Turn the range adjustment knob up 1/4 to 1/2 turn.

5. Take the transistor radio and set it to AM 600. Stand outside the
structure where the twisted wire exits and listen for the
pulsating static of the transmitter.

Gently swing the radio back and forth across the front of your body and
follow the wire out to where the loop begins. Pick either direction and
continue until the pulsating stops for a 4-6 ft area. In this area is
your break.

That's what we did. We got pretty good at it!

I bought an RF choke #273-102 which is 100 microhenries +-10%, 2amps max, rated at 1kHz. I unplugged the boundary/fence wires from the transmitter and put one lead from the choke in one terminal/plug and put the other RF choke lead into the other terminal that used to grab onto the boundary/fence wire. I then took the boundary/fence wire and connected it to a lead of the choke. After tuning my radio to 600 AM and I got nothing.

Any ideas what I'm doing wrong?

I believe you missed a key point in the procedure you pasted. They said to "Wrap the boundary wire around the choke leads"...

What they meant was to literally wrap the insulated boundary wire around the choke itself, then take the bare wire choke LEADS to the transmitter's output. Although it may seem counter-intuitive, i.e. wrapping insulated wire around an RF choke, you have essentially created a rudimentary isolation transformer. Unfortunately, they didn't say how many times to wrap it, which is a critical part of any transformer design. This will transfer the RF energy from the transmitter to the loop, but avoiding the ground return that will short out the antenna, because it is broken somewhere in your yard and touching wet dirt ...

Cliffs:

Take your boundary wire, WITHOUT stripping it, wrap the insulated wire around the choke. Leave the stripped end hanging or better yet, use tape to make sure it isn't touching anything.

Take the choke leads and tie them to the transmitter output.

Try the rest of the procedure again.

HTH

 

[rick911]

I have a 2 acre yard with invisible fence. I have used 14 gauge wire. I purchased a RF-choke at Radio Shack. I have not made this fix work.

1. I inserted the 2 leads into the 2 output holes on the transmitter.
2. Having 14 gauge wire it is very difficult wrapping around the choke. However, it is my understanding that the 2 shielded 14 gauge wires are to be wrapped around the copper of the choke. Is this correct?
3. How do i keep the 2 14 gauge shielded wires from falling off as they are thick and hard and do not wrap very easily?
4. When the rf-choke is installed correctly, should the transmitter continue to beep, which it is doing?
5. We tried tuning to 600 am. There is a radio station there and that is all we hear.

Any help would be greatly appreciated.

 

[ppatinka]

I had trouble getting this to work.

In the end these steps worked for me.

Step 1, disconnect the boundry wire and replace it with a short wire to complete the boundry wire circuit. The alarm will stop as the new short boundry wire is allowing the system to work

Step 2, reconnect 1 wire from the boundry fence. either wire will work into the transmitter, At the transmitter, One boundry wire connection will have one wire and the other will have two. The new short boundry wires and one from the installed boundry wires

Step 3 with the am radio placed very close to invisible fence transmitter and the short boundry wire, tune in the pulsing signal (I found at about 600 or 650) I could hear it along with a radio station. Sounded like electronic crickets at night. In the end I could hear the signal from 5-10 feet away from the wire

Step 4 Keeping the radio near the ground, follow the wire until the signal dies. Mark the spot

step 5 disconnect the boundry wire and reconnect the other boundry wire. repeat steps 3 and 4 ( this will take you around the boundry loop the other way. The signal died with about 20 feet between the two marked spots.

Step 6 You guessed it, the break was between the two marked spots, right where I had parked my boat over the winter and recently moved. The wire was cut completely which made finding easier.

I followed the directions using the choke and I didn't get a strong pulsing signal until I completed the circuit using the choke AND reconnecting one of the boundry wires that was wrapped around the choke. FYI worked with and without the choke as my fence was set to high for all settings, boundry width and shock strength etc

FYI on the choke, Coil one wire around the choke and connect that wire along with one of the choke wires into one boundry wire connection and the other choke wire into the other boundry wire connection. If you don't connect the boundry wire, the signal is very weak. The signal was strong and came right through the station broadcasting in the range.

I hope my extra notes help some one else. I was about to give up! The dogs slipped off this afternoon D: and just returned covered in stinky mud . I hope that is the last time that happens. Off to go wash them up!

 

[dawgluver]

I read through the posts and went to Radio Shack to pick up the RF choke and AM radio. On a whim, I went over to the wire with just the radio and tuned it in until I got the chatter. I followed it down to where I had been digging in the yard the day before and found the break immediately. There was no need to use the RF choke or even touch the box. This is just FYI. If someone can explain why I didn't need the RF choke I would appreciate it for the good of the group. All the help on this forum is greatly appreciated!!!!

Thanks

 

[The Boston Dangler]

in using actual cable locators, i've simply used an inductive clamp loosely around the cable. is the transmitter putting out 600 khz? if so, why do you need anything but the gain control and the am radio?