After a long time of preparation finally managed to place the second 6el Yagi to its position on the tower. I ran into some difficulties let say rookie’s mistakes.
As the upper Yagi feedline length was not measured originally I had quite a struggle how to calculate the exact distances. Made some “scientific” and some not scientific methods to evaluate the lengths. On top of this situation due to the tower structure there is roughly 40cm vertical offset between the two driven elements which was needed to be compensated as well. If the stack does not reach fully its potential performance most probably it’ll be due to the improper feedlines lengths.
The other mistake is rather funny. Due to the development of my antenna building technology (and some budget optimization measures) the second Yagi was made a bit different way compared to the first one. If you have a quick look the picture below you will spot out immediately. The trick is: the left hand side shot was made downwards, the right one was taken upwards. With this slight difference the 180 degree phase shift was immediately implemented. Thanks to Ed N1UR who had an incredible remote troubleshooting skills identified for the first shot what was the potential error.
The HFTA analysis shows really good improvement over the single upper Yagi. So far two rounds of targeted testing were performed but frankly speaking I cannot really say that the difference is obviously visible yet. It will take a lot more testing.
