1/4 wave home brew antenna

[pkveazey]

I finally finished my 1/4 wave 2 meter basketball antenna. It would have been finished a while back but I forgot where I stored the radiating element. I made it out of 1/4" copper tubing. I took a picture of it with my cell phone camera and now I don't know how to post the picture. I'll figure it out and then post it later. Before I install it to a pole, I'll connect it to my antenna analyzer and see if it needs any trimming.

[JohnyMac]

Send me the pic and I will post for you.

[pkveazey]

I took the picture with my Smart Phone and I have no idea how to attach it to a message and I can't figure out how to copy it to my computer. That damn phone is smarter than me. I think I'll just take another picture of it with my digital camera and then download it to my computer.

[JohnyMac]

Bring photo up on your phone
Down at the bottom of photo there is a square with a arrow pointing up.
Press the icon and an address screen will come up.
Fill in the address window where you want it sent to, e.g. email address, my cell phone, etc
Viola! You are done

[pkveazey]

I had to do a lot of weird stuff to make the photo show up in the text window. I hope it worked.

[pkveazey]

Hmmmm...... I mounted the home brew antenna on a pole and connected the coax to it. Then I came in the house and connected my antenna analyzer up. Say what? It showed that it was resonant at 150 Mhz and 441 Mhz. There is no way that a 1/4 wave 2 meter antenna should be resonant at 440. Then I connected my SWR/Power meter to it and connected that to my tri-band radio. Hmm.... It showed full power and 1.5 to 1 VSWR on 2 meters. Oops, I forgot to check it on 440. Then I connected my regular 2 meter antenna back up and then connected the home brew antenna to my 25 Mhz to 1 Ghz ICOM receiver. It hears great.

[Nemo]

Oops, I forgot to check it on 440.

So did it check out proper on 440 or did it do resonant things at 440 it should not have? 

Partially understanding minds want to know.

Nemo

[pkveazey]

Note to Nemo: When I got done checking it, I hooked it up to a receiver. I can't check the transmit items with it connected to a receiver. However, I did some antenna math and a 440 Mhz 1/4 wave is about 6.5" and any odd multiple of a 1/4 wave should be 50 Ohms. So....... The antenna is just shy of 20 inches and 6.5" times 3 is 19.5". Therefore, on 440 it is a 3/4 wave antenna and it's a 1/4 wave on 150 Mhz.

[Nemo]

I understand.  I think?  Working on learning some of this magic of sounds and pictures through the air.

Nemo

[JohnyMac]

Official Basket Ball pkveazey antenna. 

[Jackalope]

   I've got an M squared Eggbeater antenna which resembles PK's basketball antenna.  The rounded elements are the primary emitter, while the ground plane is below it.  It's an excellent antenna for satellite work, 5.5 dB gain.  https://www.m2inc.com/FGEB144RK2M   Mine is used mostly for receiving.