Sunday, October 26, 2014

Take-down Yagi On The Rocks


 
This photo finds me just off a back-country trail that borders Upper Kananaskis Lake in Kananaskis Country, located along the eastern border with Banff Park.
I have hiked this area for many years, and I thought this would be a good place to run some tests with my take-down yagi.
 

 In the above photo I have just taken a break from working a repeater back in Calgary, a distance of approximately 90 kilometers as the crow flies, with my Yaesu VX-8R attached to my take-down yagi.


 Working a repeater with a 2 meter yagi and a HT at a distance of 90 kilometers would normally not be that difficult out on the plains, however in this case the Kananaskis Lakes are located in a valley that runs in a North/South direction, and Calgary lies behind the east side of this valley.
So how did I work the repeater back in Calgary you ask.....

With Calgary located on a line that runs away from my left shoulder, and with a ridge that forms the east side of the valley in the way of my signal, I actually work the Calgary repeater by bouncing my signal off of the mountain located directly across the lake from me, and in the opposite direction from Calgary. The mountain that I bounced the signal off  of may be seen protruding from behind the tree on the left in the lead photo.




Over the years while hiking and fishing back-country lakes in the Rockies, and in particular those located in Kananaskis Country, I discovered long ago that you are at a disadvantage using your favorite HT with its rubber-duck antenna.

What works is a handheld directional antenna that you use with your favorite HT, and by bouncing the signal off of a mountain that you select through trial and error, or by finding the best surface to bounce the signal off of.
You also will find that you may have to listen in a totally different direction, than the direction you point the antenna while transmitting and bouncing the signal, and in my situation, back to the repeater in Calgary. In my case, I could hear the repeater by listening in the direction of the repeater located in Calgary.
 
 
 
On this day, besides the necessities being carried in my daypack to stay safe while out in the back-country, I also have my Nomad solar-charging panel attached to my pack, where it goes about its duty of charging the spare AA battery pack for my VX-8R.
 


 As you can tell by the fact that I was wearing my favorite mountaineering jacket along with a fleece inner jacket, and by the snow on the upper elevations of the mountains around me, it was a cool kind of fall day, and its only a matter of time before winter arrives.

Still, it was a good day to spend time out and about in the rock pile.



Here is a look at my take-down yagi being tested in the antenna lab.....
 
Yep my take-down yagi under test conditions in the antenna test chamber.
 
Expand the photo and if you look close you can see my take-down yagi mounted in the vertical position on the turn-table built in to the floor of the test chamber.
 
The receive antenna shown in the lower right of the photo is mounted on a mast that allows it to travel up and down, and this receive antenna is connected to a spectrum analyzer at the operators console located just outside of the test chamber as seen in the upper right of the photo.
 
I am very pleased with the test results, and you can see one of the polar chart graphs that was generated at the upper left in the photo.

So I end this post on a positive note, as my take-down yagi is everything that I had in mind when I started planning this project, and then building a prototype, and then testing it in the lab with positive results, as well as in the field where it lives up to my expectations.

You gotta love it when a project comes together as this one has.

Check out some of my other antenna projects here.....
http://www.jerryclement.ca/MachineShop/Antenna-Werks/
 

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