Are you looking for a fun and easy antenna project? Well the quarter-wave ground plane might be just the ticket so keep watching for more
Hi, I'm Michael KB9VBR your host for ham-radio Q&A. I'm on a mission to inspire and educate the amateur radio community
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Well, if you're just starting out in amateur radio
You may not have collected all of the resources that a more seasoned ham may have and this includes antennas
when I first started in amateur radio my first
Transceiver was a little handheld and it had sketchy transmit and on receive on all but maybe the closest repeaters. So
To the rescue would be an external antenna
Fortunately, there is an antenna that's easy to build and quite inexpensive which is the minimum amount of parts
That's the simple quarter wave ground plain antenna for VHF
So we're gonna build a simple ground plane VHF 2 meter antenna ground plane antennas
They're pretty easy to recognize by their appearance. First off. You're gonna notice the radiating element.
This element is one quarter wavelength long or about 19 inches for the 2 meter band a next up will be the radios
There'll be three maybe four radios
Going out horizontally maybe drooping at a 45 degree angle from the radiating element
Each of those are going to be a quarter wave long eat also
This particular ground plane that we're going to build today is constructed on an SO-239 chassis connector
so the radiator is attached right to the center pin of the SO-239 and the
ground radials are going to come off the
the base of the of the connector and then it and then attached to that will be a
coax cable with a PL 259 connector running into your radio
So to build this antenna first we're going to need a couple calculations
For the length of our radiator and our ground plane to do that. We're going to use the formula of
234 divided by the frequency in Mhz
To get the length of the radials and the and their main radiator
So since I'm going to build this antenna Senate antenna Center it on the 2 meter band. I'm gonna divide
234 by 146 megahertz I'll get 1.6 0 as my answer. That's going to be the length of the radiator in feet
so multiply that by 12 that'll be
The total answer for the radiator will be nineteen point two inches
So my ground radials need to also be a quarter wave long. So I'll use 19.2 inches also for their length
With that said let's assemble the parts and the tools.
I have a length of 12 gauge solid copper wire
Solid copper wire might not be the most durable, but it's easy to find. Other things
You can use maybe like our three thirty-seconds of an inch brass brazing rods
copper coated steel steel wire or even a coat hangers, Those some of those up to
Use whatever materials you can find that are handy next. I've got an SO-239 chassis connector
You'll find these at a ham fest, maybe an electronics store. You can order them online at
Amazon I'll put up with a link below in the video description below if you're having trouble finding that SO-239 and then also
you're gonna need some electrical ring connectors some nuts and bolts to attach the
radials to the base
for tools
I'm gonna be using the ISO tip butene iron since I'm outdoors wire cutters crimper pliers screwdrivers
All of that kind of rounds out the tools for the list
So to put this antenna together first measure out the elements using the formula
You'll need five. One for the radiator and four for the ground elements
Next attach and crimp the ring connectors to the ends of four of the elements then
solder the radiator to the center pin of the Esso 239 connector next
Use the bolts to attach
The radials to the connector. It's a tight fit for these bolts to go into the into the SO-239
So I first pre tapped them with one of the one of the bolts to give it a little bit of thread and they went
On quite easy. That's all there is to it. Your antenna is now complete so
Let's check out this antenna. See how it Tunes up on the SWR meter
Testing out the antenna add a
Frequency of one hundred forty six megahertz, we've got an SWR of
1.1 to one and that's with no adjustment just using our formula at all
so if you don't have a meter, this is a
excellent antenna that you can build and be reasonably sure that if you follow the measurements correctly you are going to be in tune
So to mount the antenna I saw a person using a length of PVC
As a mast you can push the coax through the PVC if it's if the P if the tubing is a 3/4 of an inch
Or larger and then just let the antenna rest on top. It's not the most sturdy type of mast, but it's quick and easy
So doing that we got the antenna up in the air. Let's see how it transmits
KB9VBR testing
N9CLC KB9VBR. Good morning Wally. It's Michael here down in Wausau
Just Working on a little project this morning a quickie quarter wave
VHF antenna, so we're seeing how it hits the tomahawk repeater
Yeah, well we only have it up a couple feet in the air so
maybe if I get her up 10 feet or so, it'll make a bigger difference, but
Thanks a lot for the come back this morning and you have a great day. We'll catch you later KB9VBR
N9CLE
Hope you found this project simple and quick to do
This little ground plane will work great with your handheld radio or also a high-powered bass radio
So don't fear putting 50 watts or more of power into it. You can also make this antenna for other bands, too
Maybe something for the six meter band the one point two five meter or 70 centimetres band
All you got to use is your formula 2 34 divided by your frequency to find that
Exact quarter wave frequency for the antenna
For more amateur radio articles and information. Please check out my blog at
www.jpole-antenna.com. If you like this video, don't forget to hit the like button and also
check out this other video that's recommended right over there and subscribe to my channel to get notified when our new videos are really
I'm Michael KB9VBR. Thanks for watching. Have a great day and 73