I have an existing Innotek SD2000 "hidden" fence (transmitting I believe at "7.5 and/or 10.9 khz") to contain our two dogs. We now have two cats I would like to contain. Innotek does not make cat collars. Petsafe does, but their collar/receivers are on the 10.65khz frequency. Can I attach both an Innotek and Petsafe transmitter to the same underground wire loop and hope it will serve as antenna for both cat and dog collar frequencies?

 

So I've been thinkin', which almost always lands me in trouble, this might not be a topic for electronic circuits. Anybody know of a good radio oriented forum?

Thanks

 

I'm not the one to be answering your question because I know next to nothing on this subject. What I do know is CB antennas. And again, I'm no expert. But an antenna works best when its length is matched to the frequency either one to one or some resonant match, such as a quarter wave antenna for instance. Since you are using two frequencies, I'm guessing that you might find some common resonant length that will allow both frequencies to be present on one antenna line. But then again I also wonder if one might cancel out the other. As for a good radio frequency website - again - I don't know.

 

I had a dog fence 20 years ago. I think it was about 10khz. I do not think about it as a radio transmitter. Current flows in the fence. A coil in the collar couples to the fence much like the primary/secondary in a transformer. If you brake the fence anywhere the collar will not work. It takes a complete loop to function. The length of wire does not need to be 1/4 wave length. 10 feet or 100 feet work just as well.

Two transmitters on one wire? I don't know. I don't like it. The different types I have used use a audio amp looking circuit to drive the fence. I think paralleling two transmitters will cause problems. I am thinking about "series".