80 Meter Vertical (Final) Update

K2WH writes "Hi, This is my third and final installment on my 80 meter vertical saga.




My last two installments were about the construction and erection of an 80 meter vertical. The titles of the two articles are “Put Up a Homebrew 65 Foot 80 Meter Vertical by Yourself” and “80 Meter Vertical Update!” both of which can be found in the QRZ archives. Look under older articles and search by my call letters.



Performance:



The performance of the vertical at this point is superior for DX stations or any stateside station 2000 miles and beyond. Superior to my 243 foot dipole at this distance. The dipole outperforms the vertical sometimes by a huge margin with close in stations < 500 miles distant. I have found stations completely in the noise on the vertical, virtually leap out of the noise on the dipole at 500 miles or less. At distances of 1000 to 2000 miles I find the vertical and horizontal antennas are about equal in received signal strength.



Mechanics:



I initially had planned on an elevated radial system. The radials left the radial ring at the base of the antenna and proceeded at a 45 degree angle to a convenient tree and then at the 8-10 foot level from then on. I should mention, the base of the antenna is about 2 feet above the ground. I quickly became apparent that as I added radials, using natural supports (trees), the hoped for symmetry of the radials was non-existent and was getting unmanageable. I also thought of the upcoming winter with the many tree branches falling destroying numerous radials. Seeing that using elevated radials was not for me or this location, I decided to put them on the ground and add additional radials over a period of time. Additionally, I initially used turnbuckles for the guy lines. These became a pain trying to adjust the position of the vertical for straightness. I dumped the turnbuckles for rope ratchets which are infinitely better for the control of the guy lines and they are very cheap about $3.50 each.



Additional Observations:



It was interesting to note that the resonant frequency of the vertical was rising dramatically from it’s design frequency of 3.750 mhz with the elevated radials. I found the antenna was resonant at 4.015 mhz as measured on an antenna analyzer. At first, I did not know what to make of this but I theorized, that using elevated radials must shorten the electrical length of the antenna - and it does!

My 2nd posting stated that I had a total of (4) elevated radials for initial testing. Well as of this posting date, I now have a total of (40) radials using # 22 enameled wire on the ground. The resonant frequency of the vertical fell dramatically to 3.750 mhz with an SWR below 3:1 from band edge to band edge. I could not ask for a better outcome building this antenna. It is a pleasure to be able to switch from one antenna to the other for best reception. Try to build one yourself, you will not be sorry for it give one a sense of satisfaction for a job planned and executed properly."