Monday, March 17, 2014

TD-TENNA





I like  HT'S and have one or more handi-talkies with me where ever I go.
Now for the past 20+ years I have built and carried some form of a portable 2 meter yagi that goes with me everywhere. I have built and used various takedown yagis over the years, but I have always felt that there were features that were lacking in the various designs that I came up with and built.


So after recently building the DF Tape measure 2 meter DF yagi designed by WB2HOL, I realized that tape-measure-elements were the perfect solution for what I had been looking for to make a very portable antenna for my needs.
The biggest problem has always been to design and build an antenna that could be taken down and stored in my radio go-box, but also could be carried in my fly-fishing chest-pack.
Now you may ask as to why I needed a yagi that I could carry while fly-fishing a high mountain stream, and one of the main reasons is this.



For example one of my favorite streams that I fly-fish is the Sheep river west of Turner Valley. The far reachs of the Sheep are located in a deep canyon located up against the front ranges of the Rockies, and once you make your way down to the river located in the bottom of the canyon, you can throw your cell-phone away as its useless with no signals available.
Now in the past I realized that the Kenwood TM-D710A mounted in my mobile and set up in crossband repeat would be perfect in case I got in to trouble while wading the river up or down stream several kilometers away from my mobile.
In theory this sounds good, but the problem was that an HT running 5 watts with a rubberduck antenna, or even a higher performance HT mounted antenna just couldn't make it in to my mobile reliably once I got some distance away from my mobile.
In the past, I have taken one of my portable yagis with me, and that was the answer as I could now easily communicate with my mobile, but the problem was the portability issue, as the yagi didn't takedown to a small enough package, and it proved to be annoying while fly fishing.

So now we're  back to where I discovered through the WB2HOL design with its tape-measure-elements being part of the answer to my needs.
The other requirement for the ultimate portable yagi, was some means of breaking the boom down to a more manageable size, allowing the complete antenna once taken apart, to fit into a space measuring approximately  9"X10".
After spending time working at my computer, I came up with a design for a takedown yagi that once dismantled measures a tiny 2"X6"x9".
Now with a set of drawings to work from, I needed a name for my antenna, and after some time spent coming up with a name, my TD-TENNA was about to become reality.

A visit to my favorite antenna supply store, that being Home Depot to acquire antenna parts, and I was good to go. Now understand I am having fun at your expense, as Home Depot don't really sell antenna parts, although I seem to be able to find a lot of what I require to build antennas while browsing the aisles of their stores.


I soon had a prototype antenna built, and once I had it tuned to my satisfaction, and tests performed with it, I knew I had a winner. This tiny takedown yagi is proving to be just what I wished I had along with me while in the back-country whether it be fishing, hiking, or just about any reason you can think of where you need more reach with your handi-talki than what a rubber-duck antenna will provide.

I cannot wait for the streams along the front-ranges of the Rockies to defrost closer to summer, so that I can hit the streams with my new TD-TENNA in my fly-fishing chest-pack.

Another capability that I have while out in the back-country fly-fishing, is APRS capability, and this comes in the form of my Kenwood D72 that is pared up with my Garmin Montana. With my Kenwood TM-D710A in my mobile set up as a digipeater, I am able to beacon through my mobile which in turn allows me to get into the Alberta wide APRS network, enabling those of whom I informed before leaving home as to my whereabouts as seen on a computer screen at aprs.fi, while I am in the back-country.
 
 
The Montana proving to be compatible with my Kenwood TH-D72A, provides GPS location information for my transmitted APRS beacons, and it shows the received APRS information on the map of the Montana as well.

With the Canadian Topo maps enabled, I now have national, regional and local parks, forests and wilderness areas, including points of interest such as campgrounds, scenic lookouts, hiking trails and land contours shown with elevations, as well as elevation tracks and more.

 The view that is shown on the Montana in this photo, shows the screen with a number of beaconing stations depicted. I also have assigned custom Icons to each station, or at least for the hams in my local area, allowing me to identify them at a glance. I also can change the size of the font for the callsign, allowing for easy reading of the information shown on the screen of the Montana.


Of course...all this is happening while I am operating as a fly-fishing pedestrian mobile, and both my Kenwood D72A, or my Garmin Montana, are located at my finger-tips, as they both are carried nicely in my fly-fishing chest-pack.

Note...all photos expand.

For more info as to my goings on...

www.jerryclement.ca



 
 

No comments yet