The backpack mounting method has been used in various ways by research biologists for many years, with some better than others. Mark Williams of Alberta Canada refined the best basic design and proved its viability for falconry. This figure eight approach was further simplified and put in to production by Marshall Radio as the “TrackPack Mounting system” to add yet a fourth mounting method to choose from. In just seven years it has become a widely used mounting option by falconers all over the world. The TrackPack is the ‘ready-to-go kit’ for the backpack mounting method. Starting with a gently curved Mounting Plate machined from UV-protected Delrin plastic, we add 36 inches of small width Teflon tubular ribbon and a small brass crimping ring produced just for this purpose that’s internally threaded for maximum bite into the ribbon when making the final setting.
Only Tubular Teflon Ribbon used
The material used for the actual harness is critical to the safety of the idea. Tubular ribbon has no edges to cut or injure, and is inherently slippery and smooth. This is the same material that has been selected and used for many years by the Peregrine Fund here in the US and around the world for the attachment of harnesses in their migration studies.
Smooth and slippery Delrin mounting plate
We originally used a simple leather pad with an aluminum tail piece mounted to it for the mounting plate. What was learned is that the leather would, over time, develop a slight figure eight shape as the sides curled up through pressure between the shoulders during the upward wing strokes.
We replaced leather with a similar shape piece of machined Delrin whose width was narrow and whose length just enough to attach the tail spring and protect from the bottom of the transmitter. Delrin is a high-strength machinable plastic and will not act as a heat shrink or otherwise cause irritation in relation to temperature.
All edges are rounded and smooth, and the overall shape is gently curved to better match the shape of the back. We use an expensive UV-resistant Delrin that is rated for 20 years in direct sunlight without becoming brittle or cracking. So, it’s possible your kids will inherit your used mounting plates.
Extra length of ribbon for sizing and extra fit
Starting with a length of 36 inches, or 18 inches per side, allows enough extra room on most Hawks and Falcons to have about 5-7 inches extra to use for manipulation, sizing decisions and general handling.
Custom internally threaded brass crimping ring
We take brass tubing and tap a thread into it to provide a better bite when it is crimped. It has been tested, by hanging a bucket with weights, to around 25 pounds of holding strength.
The Micro size TrackPack uses the tightest smallest ribbon, and will only accommodate a Micro sized spring.
The Regular size TrackPack will accommodate all transmitters, including the Micro, although it will not be quite as snug.
The XL or Eagle size TrackPack uses the 1/4 inch ribbon and a longer mounting plate helps position the ribbon lower on the torso. This can be used for large Buteos as well.