The old Mark I gray box and leather collars, and the new Mark III box and collars. |
Yesterday, I recounted the very early history of terrier and ferret locators, the electronics for which were originally created to locate golf balls lost in the rough.
In 1975 a Suffolk, England telephone engineer by the name of Paul Walker was looking for a way to locate his ferrets The Bleeper had just come out and was not yet in common knowledge, but Walker was thinking along parallel lines.
I've looked for the patent for the Paul Walker Deben locator, but cannot find it -- I'm not sure why. It could be that I am incompetent at patent searches (been said before!), or it could be that Walker is simply using technology that is now off-patent, as an animal tracking transmitter that appears to be nearly identical to a Deben locator (albeit with a higher frequency) was published by the American Institute of Biological Sciences Bioinstrumentation Advisory Council in 1967 (information module M15 prepared by William W. Cochran, December 1, 1967)
Adding credence to the idea that the product is both off-patent and not novel is the fact that Deben wiped all identifying marks off the internal circuits of its Mark I box -- a foil to copying. In addition, no patent is claimed on the old box or the packaging.
It should also be noted that the Mark I and new Mark III Deben locators seem to be not much better, in terms of distance, than the original "Bleeper" invented by Stephen Alexander Horchler who applied to patented the device in 1971 (granted in 1974).
Could the Mark I and the Mark III be simply a better-packaged version of the same thing? Very possibly. The Bell and Flint terrier locator, as I have noted in the past, is simple a repackaged Pieps Powder Puff avalanche locator.
Either way, the Mark I Ferret Finder and Terrier Locator came out in 1978, and remained relatively unchanged until it was discontinued and replaced by the Mark II (a design failure) in 2004 and soon after by the Mark III (the current kit) in 2005 which seems to be a marked improvement over the old Mark I.
The Mark I Deben locator receiver was the same old Bleeper long-wave low-frequency radio receiver, though its receiving range was constricted so that it could not pick up commercial radio transmission, and instead of a speaker that could play music, it now emitted a simple knocking sound that became louder or softer depending on how close you were to the collar transmitter. A dial on the side of the box was turned up or down to hear the box, with the volume dial corresponding (roughly) to the number of feet down the dog and collar were located.
The old Mark I and current Mark III Deben technology appears to be about the same technology, and the range of the collar is the same. The differences are as follows: 1) The new receiver is bright orange and appears to be a great deal more water and dirt resistant; 2) the new receiver has a battery that is much easier to swap out; 3) the new collars are now enclosed in a "watch case" that no long needs to be taped (a major pain in the ass in the old Mark I); 4) the leather or nylon of the collar is now much easier to replace; 5) the new Deben collars are turned off and on with a simple magnetic reed switch, which means that batteries last longer and do not have to be changed out between every foray into the field, and; 6) the old "knocker box" sound has been replaced with an R2D2 electronic sound which is odd and unmistakable in the field (unlike the knocker box which could sometimes be hard to hear in high wind).
2 comments:
Does anyone know the actual radio frequency the Mark III transmitter operates at?
All through-ground locators use low-frequency (Khz not not mhz). The current standard for avalanche locators is 457 khz (made a standard in 1968), but the deben locator may be a bit lower than that. I used to know, but have forgotten. If you are looking to build your own locator/transmitter, 457 is the the frequency to use.
As I noted in 2004:
"It is possible right now to put together a 457 khz avalanche locator system for $250. Since this is based on retail prices for the equipment, I think the components can probably be bought in bulk for half that, with someone making a handy profit while cornering the market for the next 10 years."
In fact, Bellman and Flint did that exactly.
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