Radio Dog Collars and Audio

[pinkmouse]

Originally Posted by regal

edit: maybe the warning beep is 18khz, and thats where the resalers are getting the number.

That makes perfect sense to me, 18KHz is right in a dog's sensitive area, and inaudible to most humans so won't cause a nuisance to neighbours.

[madtecchy]

Maybe doing a google on RF criminal tagging systems may bring some light

[DF96]

This probably using 18kHz magnetic field (i.e. near field), not true radiated RF. You need a rather large antenna to radiate any useful amount of 18kHz energy, but a simple solenoidal coil can generate a useful magnetic field. The dog presumably can't hear a magnetic field, but the receiver on his collar can pick it up and administer the appropriate stimulus.

Looks like a good way to annoy any neighbour with good high frequency hearing and decent tweeters.

[tubelab.com]

The US Navy operates a VLF radio transmitter in Cutler Maine, call sign NAA. It operates with a power of up to 2 MEGAWATTS! Back in the 70's and 80's we used their signal as a back up time standard when WWVL was not available. They operated on 17.8KHz at the time, but I believe they have since changed to a different frequency. All of our equipment is now GPS referenced. The real purpose of NAA is communicating with submarines since VLF frequencies will penetrate earth and water. A dog fence with a few milliwatts of power and a small antenna is not going overpower 2 megawatts into miles of antenna.

The dog fences do transmit an electromagnetic waves, not audio. The signal is not audible, but it could be picked up by phono cartridges, guitar pickups and poorly shielded audio equipment. The transmitting antenna is usually a ferrite rod with multiple turns of wire.

There was a dog shocker on the market several years ago that used a buried wire as the "fence". When the dog approached the fence the beeping started. If the dog got closer.....ZAP! That version put a fairly large current through the wire and it did find its way into stereos, answering machines, headphones, and yes guitar amps.

[sofaspud]

Can dogs, or humans, hear 18kHz RF??
Anyway, I was told by the manufacturer that the IF-100 transmitters operate on a 18.7 kHz frequency.
I'd say there is a possibility of interference, and thoughtful placement of the transmitter and audio equipment would be the easiest prevention.

[vinylkid58]

Originally Posted by tubelab.com

There was a dog shocker on the market several years ago that used a buried wire as the "fence". When the dog approached the fence the beeping started. If the dog got closer.....ZAP! That version put a fairly large current through the wire and it did find its way into stereos, answering machines, headphones, and yes guitar amps.

The neighbors had one of these electronic fences to keep their Jack Russell Terriers from escaping. The collars were supposed to keep them from barking, but didn't work very well. When they got rid of the female (the troublemaker), most of the barking and escaping stopped.

jeff