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.
This article was originally posted on www.mikestechblog.com Any reproduction on any other site is prohibited and a violation of copyright laws.
i recently obtained my foundation licence and am intrested in making anttenas, i quite like the one here so will be attempting to copy it. i also bought the book simple and fun antenas for hams by chuck hutchinson and the first anttena is very similar to this, so anyway im quite excited to have a go at this. the instructions are easy to understand and after all ham radio is all about experimenting.
thank you for posting this.
Your column is fantastic!
I am new to ham and learning a lot as I go. We live in a very remote area, I want to provide assistance to travellers. I will be building this antenna soon.
Thank you for sharing
Thank you for your kind words. Have a great day!
— Mike WB8ERJ
Hi Mike, thanks for this manual. I will start with the project soon. I want to use the antenna for the 2 meter band and the instructions for the 2 meter band are loud and clear. I often see the 2 meter and the 70 cm bands combined in one antenna. Is that also possible with this design?
Keep up the good work!
regards, Job (Netherlands)
Hello from Netherlands!
Since the 70 cm band is approximately the 3rd harmonic of the 2 meter band it will probably work ok. It is certainly worth a try. If you build this antenna, feel free to post another comment letting me know your results on 70cm.
— Mike WB8ERJ
Already did (25 years ago.. ). It loads fine from a SWR perspective, but it’s no that good because, working in the 3rd armonic, radiation stops being sideways and starts being upwards, making an excellent “sky heater”. This said, I would always carry it in pieces in the trunk of my car and use when possible. Made quite some contacts on both 2m and 70cm
You are correct about the “sky heater” on 70 cm due to the high angle of radiation.
— Mike WB8ERJ
I gotta tell you – thanks for these instructions. I built this antenna this weekend – with hopes of putting it in my attic, as our HOA doesn’t allow for antennas.
I finished it Saturday, and before I could get it in the attic, I temporarily set it up attached to the top of our 5′ fence, so it’s probably about 7′ in the air, largely between two 2-story houses.
With my little 50W mobile, I was able to reach a repeater about 50 miles away, and they had a great copy. I’m hearing repeaters 60-70 miles away clear as day.
I think VHF conditions are prime now, so that helps, but this is an amazing little antenna for the less than $20 I have invested in it.
Thanks for the step by step.
Nice!! Glad it worked out for you.
— Mike WB8ERJ