Build an HF Ham Radio Dipole Antenna
Making a compact dipole for 40 metre operation Many HF antenna designs require physical length to achieve resonances at the lower frequencies. This is not always possible in all situations due to the space available. However, there is a way to reduce the overall length of an HF dipole . Jul 30, · I'm often asked how to make a dipole. In this video I use materials on hand to build a meter amateur radio dipole. I hung it on the antenna test rig I bui.
Many HF antenna designs require physical length to achieve resonances at the lower frequencies. This is not always possible in all situations due to the space available.
However, there is a way to reduce the overall length of an HF dipole through antennna use of loading coils. Adding inductors to your dipole makes it possible to reduce the overall length of the antenna.
The loaded dipole opens up the options for many armature radio users faced with space constraints. Below is one example of how to build and how to make spaghetti squash recipes a 40 meter loaded dipole using basic materials.
To design the dipole I used the fantastic Antenna design page created by Martin. I needed my dipole design to be 12 metres long and resonate on 40 mertre, the following design was generated:. The calculator provided on the Martin.
Meserve website gave me the basic coil design parameters. I had some 50mm outside diameter plastic pipe and 2mm poly-weave wire, from this I had to work out the number of turns per inch. I did this by marking one inch on the pipe and fipole some of the wire and counting the turns. I entered the details into the calculator which then gave me the number of turns and coil length required to achieve the required inductance:.
To construct the coils I marked out the width of the winding and the location of the terminal holes using a metalwork scribe. Two M4 terminal bolts were fitted, a ring terminal was crimped to one end of the cable to be used for the winding. The ring terminal was fastened to the terminal bolt, and the cable wound tightly around the pipe. When the desired number of turns was achieved, the cable was cut and the second ring terminal fitted and fastened to the remaining terminal bolt.
The how to build a 40 meter dipole antenna was tidied up, buidl super glue used to hold things in place. A cord grip was constructed by drilling two holes in the pipe and inserting a 4mm cleat into each hole purchased from ebay. The antenna what are the most common minerals in clastic rocks why was antennq threaded through the cleat and secured with a nylon tie-rap as shown in the image above.
The antenna was constructed on the ground as per the dimensions shown. The ends were terminated by threading the cable through a 'dog bone' insulator and securing with a cable tie. I left about mm of extra cable folded over on the ends to aid tuning, just in case I got something wrong.
All of the extra cable was to be later removed during tuning, bringing the antenna back to its original design lengths. Once everything was connected up, I sprayed all of the connectors and joints with automotive lacquer to help protect them from corrosion.
The dipole was attached between my meted mast which is bolted to the side of the housethe other to a corner fence post at the end of the garden. A pulley had been previously fitted to the mast, this made things a lot easier.
I did note that the balun and coils added some weight to the antenna, weight saving ideas would need to be considered for future designs! Some tuning was needed, the extra lengths I added during construction had to be trimmed off.
Using an antenna analyser a low SWR was seen at 7. Good news! Once the antenna was up I could see that there was room to make a longer version. Again, by using the Antenna design metr created by Martin. This change offered some improvement and broadened the usable frequencies of the antenna. This was an enjoyable project which offered big rewards for my efforts. The performance is okay, although you can see the SWR changes noticeably antwnna the 40 metre band when tuning away from 7.
Weight is an issue and I atnenna worried about the tension put on my mast mount, maybe how to find a good breeder guy rope will help?
Overall I am very happy, the antenna works and fits into my back garden. Contact us: radio adaptivebms. Making a compact dipole for 40 metre operation. Loaded dipole. The coil design. I entered the details into the calculator which then gave me the number of turns and coil length required to achieve the required inductance: Input parameters Inductance required Making the coils. Dipole loading coils. Loaded dipole loading coil termination. Mounting the dipole. Mounting the 40metre loaded dipole.
Dipole loading coil. WSPR report on 5 Watts. Longer version. See my trapped dipole page for the best solution for my modest back-garden Please like or share this page:. All rights reserved. Log in Log out Edit.
Feb 17, · 38 Responses to Ham radio meter dipole: your first antenna. dcasler says: January 30, at pm You can fold it back even though it’s insulated. Greg says: January 2, at pm I made use of your page and a 3D printed center support and insulators to build my first antenna. Put it up yesterday and made several POTA contacts. meter band with SWRs under The bandwidth limitations on and 80 meters can be largely offset with an antenna tuner. Title: Build a Space Efficient Dipole Antenna for 40, 80 and Meters File Size: KB. Apr 19, · This antenna works without an antenna "tuner." Multi-band operation is possible with an antenna "tuner." Here are some comments from W4AOX: In this video I go through the steps to build a very simple, inexpensive multi band dipole antenna for the 40 and 20 meter amateur radio bands which can be used either at your home or in the field for off.
This is post in a continuing series of simple ham radio antennas. Multi-band operation is possible with an antenna "tuner. In this video I go through the steps to build a very simple, inexpensive multi band dipole antenna for the 40 and 20 meter amateur radio bands which can be used either at your home or in the field for off-grid emergency communications.
Additionally, this DIY wire dipole antenna will also work on the 15, 12, 10 and 6 meter bands if your radio has an ATU or you have an external tuner. Parts List: 1ea. Cover 1ea. PVC Pipe Coupler 1ea. This helps support the channel and allows me to continue to make videos like this. W4AOX is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.
Thank you for the support! The music in the video was used by license from TeknoAxe. Thanks for joining us today. Thank you for visiting my Amateur Radio Blog. I value your comments and suggestions. April 19, Post July 15, The G5RV is an excellent choice for the 20 meter band. Read more. July 11, Like many amateur radio operators, I live on a small lot surrounded by neighbors, utility lines, and civic-minded citizens concerned about the "attractiveness" of my community.
Whether by design or outright fear, I've adopted the "stealth" approach to ham radio antennas. It's the old "out of sight, out of mind" idea applied to amateur radio antennas. So far, my modest verticals, loops, and inverted vees have blended well with the vegetation and trees bordering my small backyard. Vertical antennas have always been a problem because of the limited space for a radial system.
July 14, In this short, well-made video, "taverned" shows us how he used a mag mount antenna, a simple C clamp, and a basic ground system to convert his mountain bike into a mobile station. The project is straight forward, simple, and gives you emergency communications while you peddle down the road.