|Ham Radio - Antennas|
To calculate the length of the antenna's vertical element, use the following formula:
Length (in.) = 2808 / F
Where F= 146 mHz.
If you want your 2 meter antenna to resonate at a different frequency, then use the above formula accordingly. For me the length I want is 19.25" so I make the vertical element a bit longer. This allows me to tune it in with an SWR bridge.
For the radials, you want them to be 5% longer than the vertical element, so for me, they would be 20.25 in. So I cut mine to 20.5 in. and then took a pair of pliers and put a little hook on the end of each radial. This will provide some eye protection if someone gets hit in the eye. (not much though! so be careful!!)
Once your 2 meter vertical antenna is tuned, it needs to be weather sealed with silicone sealer. Don't be shy about putting it on. In this case, more is better! Make sure it covers the vertical element at the solder joint and all over the top of the SO-239 connector, as well as the screws that hold the radials on. Also make sure the underside of the SO-239 connector and the PVC pipe meet is completely sealed as well.
I am very pleased with the results of my new 2 meter vertical antenna. I can now easily hit several of the local 2 meter amateur repeaters in the area.
-- MikeThis article was originally posted on www.mikestechblog.com Any reproduction on any other site is prohibited and a violation of copyright laws.