What are the different types of Ham Radio Antenna?

can you tell the difference between a DI Poole and a jpole we'll explain some antenna Basics coming up K4 n this [Music] is hi I'm Jim N4 bfr one of the instructors at ham radio prep we deal with antennas every day in ham radio but sometimes it's a little overwhelming so we're going to take you through the most basic antenna [Music] types one of the first antennas you may encounter in your ham radio experience is this one and it's most basic you would call it a vertical antenna it's affectionately called a rubber ducky it's typically just what comes with the radio the manufacturer's antenna is usually a compromise they've designed it so it trades the convenience of size for radiating performance the typical Rober ducky is only about 7 in high that's one10 of a wavelength on the 2 M BAND so coils and windings are used to electrically lengthen it if you want to change that for something different there are options third party antennas come in longer and shorter sizes if you want to get more performance at a distance pop a longer antenna on your handheld if you're mostly using it around the house or apart make it easier to carry with a smaller antenna a jple is a multi-band multi-element antenna that's shaped like the letter J it's usually used for VHF and UHF Communications and it could also be connected to be an enhancement to your handheld antenna a rolled up jpole is a great antenna for emergency go kits when you need maximum Effectiveness it's usually made from antenna ladder line and can be stashed in a go bag if you're looking for something more permanent like for your house you'll find instructions online on how to home brew a jpole out of copper pipe so if you take a look here you'll see the the ladder line breaks and it makes this J shape and that's why they call it a jpole this jpole is nice long antenna so you got a lot of wire in the air to oper on 2 m and [Music] 440 the ground plane antenna is another option to build or buy this can be a smaller antenna for VHF and UHF operating it can also be a 33 ft tall model to get in on some HF bands commercially you'll see these as halfway or 5/8 W vertical antennas with smaller ground radiating elements if you choose to build one for VHF or UHF many go the route of picking up an so239 connector and some stiff wire or an old coat hanger if you're trying to make Simplex contacts or get into a repeater on 2 m or 70 CM a vertical antenna is your choice for cities or flat areas you don't give up signal strength in most directions and most repeater antennas are also vertically oriented [Music] let's think about a vertical antenna mounted on your vehicle from the looks of it it's a vertical without the ground plane right well not exactly because in this case your car or truck acts like the ground plane verticals on cars tend to be a quarter or half wavelength for 2 m with a larger antenna once again you'll trade size for gain which means the antenna against directivity in this this case the directivity would be away from the car the term dipole might sound intimidating but it really just translates to two elements di Poole or two pole did you ever buy a stereo receiver and get a t-shaped piece of wire to improve your reception that's sort of a dipole antenna you'll see dipole antennas both above and below 30 MHz but they're much more popular on the high frequency or HF bands because they're easy to put together with a Balon a Balon is the device that connects the antenna to the feed line of the elements usually some spare wire like speaker wire or ethernet cable a halfwave length dipole is the typical one you'll see here's an example if you're making an antenna for the 10m band using a frequency of 28.5 mahz your half wavelength antenna will be a total of 5 m across or half the wavelength in American units that's 16 1/2 ft take your 5 m and divide it in two again to get the length of the two dipole elements in our example that's 2.5 M long or about 8 and 1/4 ft on each side put an insulator on one end and a ballet in the middle hanging from your deck or in a tree and you're on the air the math works on other HF bands too for instance the lower the band the longer the antenna so an antenna on the 40 M BAND would be 20 M across or about 65 ft here's the formula you need to convert frequency to a tenna length in feet don't worry about remembering it cuz there's plenty of dipole length calculators online the nice thing about a horizontal Al dipole is a standard reference for an antenna without gain this means it's a basic antenna that can be used for transmitting or receiving this is a really easy build as well and you can customize the length to fit your yard or the available space you have to work [Music] in so far the antennas I've mentioned here have been mostly omnidirectional they generally work well in all directions so what about directional antennas a directional antenna pulls signals that would have gone in all directions and focuses them in a narrower beam this is called a yagi antenna and it starts with a dipole we'll call that the driven element The Driven element gets surrounded with more dipoles one's called a reflector and the others are called directors it works like this instead of setting a strong signal in all directions a reflector just a little longer than our driven element takes the signal coming its way and bounces it back towards the driven element this amplifies the signal or adds a gain in a direction the directors which are smaller than the driven element help point the signal in the right direction the more directors there are the more directionality the antenna will have some directional 2 m antennas have up to 28 elements many hands have success with 2 m yagis they make from old tape measures and PVC pipe it's a quick and easy project if you're far away from a repeater or looking to do things like communicating with satellites or the ISS it's time to evaluate different directional or yagi style antennas yagi antennas are popular on HF to help bring in the DX signals from around the world it's a very versatile design that you probably see more than you think the biggest trade-off with a yagi if it's not pointing at a signal it's much harder to hear it and talk to that [Music] station antennas are a great thing to experiment with hamson designed everything from flag pole vertical to hide from their homeowners association to Loops traps cages and other unique designs in our video on the top five HF antennas for new hams we talk about the strange antenna challenge this is where hams use things like bed springs or street signs as makeshift antennas you can check that video out for more information there's a key Point here though about strange antennas that is some antennas are better than no antennas if you've got the tools to build or buy one great if you have 70 ft of spare ethernet cable after a rewire job you can probably use that to get on 40 m so be adventurous and experiment if you have thoughts or questions about antennas check out our other videos and subscribe to our YouTube channel if this inspires you to get on the air and start building your own antennas visit us at hamradio prep.com for license courses that tens of thousands of people have used to get their call signed and get upgrades I'm Jim N4 bfr and we hope that you get that antenna set up so we can hear you on the air [Music] soon

Channel: Ham Radio Prep

Views: 10,360

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Id: 8byEmQvLHr8

Length: 9min 49sec (589 seconds)

Published: Fri Jan 19 2024