Thanks to you, I made one of these antennas. I am soooo pleased. I am getting 4 and 5 of 5 bars. I am lucky that my towers are east or west of me, so this style works perfectly for my location. Total cost of new 1/4" x 10' copper tubing and transformer, $17
1) Both antennas should be 1/2 of a wave length. 2) The spacing between the arm with the transformer and the folded section matter to the performance. If you get those the right distance, the folded dipole has a wider bandwidth than the plain dipole. A pipe having a larger diameter than a wire also makes the bandwidth wider. 3) Your idea of impedance is correct. It works best when the impedance is matched. This also means that the resulting impedance is at zero phase. With a zero phase on the impedance (also call resistive), the voltage and current stay in step with each other.
Thanks Mr. I'm gonna make a folded dipole tuned for my favourite fm radio channel. Probably use a piece of square plastic from a discarded porch railing railing. (Non-conductive even when wet)
The folded dipole is the same length as a simple dipole. L (ft) = 492 / f ( MHz ). The characteristic impedance (Z) of a simple dipole several wavelengths above ground is 72 Ohm. It can be fed directly by 75 Ohm coax. A matching transformer 300: 75 ohm is unnecessary and will only cause signal loss. Folded dipole construction depends on the conductor diameter, spacing between the conductors, and the dipole length. Shape of the ends makes no difference. Characteristic impedance of the folded dipole is typically known as 300 Ohm. In practice however it is 200 Ohm therefore a matching transformer is needed for a coax downlead.
I am trying to build one of these and have trouble physically adjusting the lengths of the dipole to the frequency I want. The thing that makes F.Ds work without being the exact right length is because the folded dipole is very wide banded, so if you get close, it will still be an improvement. A regular dipole has to be cut closer to the correct resonant freq. Also, your signal strength should be higher if you run that old 300 ohm tv twin lead wire all the way from the antenna and put the 4:1 300/75 ohm balun transformer at the bottom before tv. That old twin lead has 1/4 the signal loss of coax. If you cut antenna elements exactly right length, it will be even stronger, but you will need a $45 NanoVNA antenna analyzer to do it.
@@NorthcoasterHobby For FM reception in order to receive most of the channels and in stereo you must mount it sideways otherwise you have to rotate the antenna each time you search a channel. In Europe most countries broadcast FM vertical so the antenna mounted horizontal will do a poor job. DAB+ can only be received vertical.
If the antenna is mounted at a 45-degree angle, halfway between horizontal and vertical, it will receive each polarization at 70 percent strength (cosine of 45 = ,707). Losing 30 percent of a signal is rarely a problem; if it truly is, buy a second antenna, some cable and a switch. That way, you can choose between a horizontal or vertical antenna at the receiver. Radio/TV hobbyists nearly all have more than one antenna. Anyone can do it.
@@bloggerccc In my case for FM I installed a 3 elements Yagi antena vertical mounted, for VHF High (DAB+) I installed a 7 elements Yagi antenna vertical mounted, and for UHF a 19 elements Yagi antenna horizontal. An FM+VHF+UHF combiner and a 4 output amplified splitter. I have excellent reception on both TV and radio (FM and DAB+). I prefer to install multiple antennas to get the best reception.
Sometimes these simple designs work surprisingly well. I'm much further from the towers, so multiple similar dipoles are needed. Hence Channel Master 4221. That design has been copied longer than I've been alive.
To measure the signal strength I’m using a digital converter box. Most of them have a built-in signal meter. Core Innovations OTA Digital TV Converter Box DVR Review - DTV Converter Box with PVR Recording th-cam.com/video/TK4IUDi83r0/w-d-xo.html
I'm not clear on how dipole antennas are supposed to be aimed - should the elements point at the broadcast tower or be perpendicular to the tower? Helpful video but I'm going to try your simple non-folded one first.
"I kinda spitballed it". 🤣😂 yea, I made a couple of antennas myself, a two and four bay bow tie, and a gray-hoverman. I wish you had some UHF stations available. would be interesting to see if this folded dipole model could pick up UHF.
Improve performance of this antenna. Your overall length should be 104 inches. About 8 ft. Granted not ideal, but you aren't getting the most gain or efficiency with the shorter length. It's a wonder you are receiving. As is each side is 1/8 wavelength long. Ideal construction would be found in an antenna handbook. But when I build these I use lengths of 300 or 450 ohm flat or ladder line. The spacing is already set. Split one side at the mid point and solder your transformer or another length of your line one to each side. As in common FM stereo antennas. You get improved gain (around 3 dbd) and bandwidth. You may do as well with a fan dipole and easier construction, as you aren't transmitting. Or just use an folded dipole antenna made for fm stereo. I applaud your building efforts. I hate that everyone wants to buy lower quality when they could build better for free. Keep it up.
@ToddCarpenter-N9YSQ and Northcoaster Hobby. I made a Folded dipole antenna a few years ago to pick up channel 4 in my area (used a stripped down electrical cord). It was a full wave antenna, so it is rather large in my opinion. I just stumbled upon this video and see the success with the half have folded dipole. I just tried to make a half wave to pick up channel 4, but didn't have any success. Do you have any thoughts or advice as to why it isn't working? I realize you can't see it, but I am using speaker wire this time (for testing purposes). I need to make an antenna for someone to pick up channel 12 (real broadcast channel) and I would like for it to take up as little space as possible. Being a novice, this Half Wave Folded dipole appears to be the only option, if I can get it to work. Also, the diameter of wire or tubing that is used for an antenna, I presume that the large the diameter of the wire or tubing helps in better reception? Thanks for posting this video and for your reply.
It's about resonance. Resonance happens best on full wave, 1/2 wave, and 1/4 wave. You actually get a bit of gain if you make a full wave x1.25 length.
Awesome vid! I was hoping you would compare the double dipole to the simple dipole for the Hi VHF range - I have wanted to understand whether there is benefit to a double dipole of full wavelength length in comparison to a single dipole of half wavelength length.
@@spirahsass Here are a couple of simple dipole antennas I made. You can see the signal levels for each for comparison. Build a Homemade DIY TV Antenna from copper wire - dipole OTA TV antenna for local channels th-cam.com/video/bYfZu923aTY/w-d-xo.html How To Make a Simple DIY Homemade Dipole TV Antenna - get free OTA TV Channels th-cam.com/video/6tqQkylXZFM/w-d-xo.html Thanks for visiting my channel.👍
Since I live in an area where Low VHF channels are plentiful. And the dipole needs to be so large in size to receive the signals accurately. Would making the antenna folded on itself two time instead of your one fold making the antenna a smaller footprint help increase the gain of the signal Sir ?? Thank you for your video Sir. Nice work with honest information for one to learn from. Peace vf 😀😀😀😀😀
@@victoryfirst2878 I would not do that because you want to maximize the amount of signal that the antenna grabs. Low-VHF wavelengths are long. So either use a folded dipole like this or long dipoles (unfolded),
@@NorthcoasterHobby I understand what you said Sir. Would making the antenna say 1.25 larger than the standard wavelength increase the reception ?? I read on WIKI using the slight larger size increases the signal gain ?? Reason I am asking as the WIKI article on dipole states the the 5.2 directive gain is achieved by what the author stated. Thanks Sir.
@@NorthcoasterHobby Would using the wire length of 1 1/4 times the frequency wavelength give you a 5.2 directive gain dBi ?? How about folding the loop a few times to reduce the width size keep the gain the same ?? What I mean is the ends are S and a half shaped. Thanks vf
Resistance is when current or voltage is restricted in a Direct Current (DC) circuit When resistance is applied to an Alternating Current (AC) circuit, it's called impedence. Radio waves are electro-magnetic AC, so we talk about impedene at antenna feed points. Antenna dimensions are criitical for transmitting so your rig doesn't melt. For only receiving, the math is not so critical. Build one and try it.
Resistance is a measure of voltage divided by current in a resistor. Impedance is the generalized notion of voltage divided by current for any component.
Use a 6:1 Balun instead of the transformer and you get a good connection to 50 Ohm coax, with a minor adjustment to the length it will now work as a transmitter antenna in the Amateur 70 MHz band.
So changing the transformer to the balun you suggested turns this into a Ham Radio antenna? Cool! Is that 6:1 balun something that can be bought or built? Does Ham Radio use 50 ohm coaxial?
@@NorthcoasterHobby Yes. Almost all Ham transmitters and receivers have 50 ohm output/input impedence and use 50 ohm co-ax to the antenna. 6:1 baluns can be bought or a look at the ARRL or RSGB websites will show you how to make your own. Your choice. They are so cheap it's hardly worth the effort. Your local ham radio store will have them in stock. Ian G4JIU
As I said in the video I used an 8 foot piece of tubing and bent it around a radius to get a folded dipole of about 4 feet. RF channel 2 requires dipole elements of about 8 feet (4 feet each), so I figured that would be close.
I've made antennas for cb and 10meter freeband back in the day. I currently made a simple uhf loop just to see what channels would come in. I was amazed to see 95+ channels come in! Most signal ratings are between 50-75% . My older Tv (still flat but older tuner) doesn't seem to tune all digital channels. I think I'll try this vhf dipole and see what happens. My Tv doesn't show the frequency...just shows channel numbers like 5.1 ,5.2, 5.3...ect
To make this a deep fringe antenna would require adding a long boom, longer elements(several more), as well as several director and reflector elements. I suppose to make an omnidirectional antenna you could form the metal into a loop and orient it horizontally.
@@NorthcoasterHobby Would you have an plan that I can go by to make me one Northcoaster Hobby ??? What I need is a ultra deep fringe omni-directional antenna. I am sure I could make me one that has been proven with just a plan from you Sir. Thanks too.
If you are suggesting what I think you are suggesting, the answer is "it won't work very well. A simple 1/2 wave dipole tends to have an impedance of no more than 73 ohms. If you do two of them both connected to the same transformer, you will have an even lower impedance. Thus the balun intended for 300 ohms will be badly mismatched.
@@kensmith5694 - thanks for the reply. I don't know much about the electronics involved, so I'm just trying to figure out a system that might work well for me. Are there other baluns that would handle that better, or are they all a standard 300 ohms?
@@doplinger1 The 300 to 75 Ohm balun is the one you are likely to find out there. Other impedances can be made but there isn't much market for them. A good first step for you is to find out the RF frequencies that are going to matter to your antenna. There are sites out there that will take your location and tell you the stations you might get. On some of them, you can see frequency directly. On others they tell you the "RF Channel" that you then need to go look up to find the frequency. If all the "xxxMHz" numbers cover much less than a 2:1 range, a folded dipole may very well work for you.
Like to see try out my home made antenna single six foot dipole works great because it's all directional made out of the same material you're using now
I’m about 7 miles from the towers in my area. I’d say a homemade antenna like this might be good for 15-20 miles, give or take, under ideal reception conditions. No antenna will capture TV signals from 200 miles away. The curvature of the earth restricts reception to a maximum of 70 miles. Have you considered FTA satellite? TV Channels on Satellite 99.2 West KU Band Galaxy 16 - FTA Satellite TV th-cam.com/video/74ATpYK84x4/w-d-xo.html Getting Free Satellite TV th-cam.com/video/qBOVmYHAGWc/w-d-xo.html
Double penny loop works better than a folded dipole in my experience. You can go full wave x1.25 length with some conductive copper tape in your attic.
Thank you Northcoaster Hobby for making this video about Folded Dipole and if you Northcoaster Hobby still have that folded dipole antenna for Channel 2 can you test it indoors? I'm curious to know if it's possible to receive low vhf channels 2-6 using single 300 ohm folded dipole antenna cut for the frequency. Alexander 98.
I still have it. I’ll try it out sometime. The indoor reception of RF channel 2 varies greatly from season to season. Winter is usually better for indoor reception for me on account of the trees have no leaves. Thanks for watching!
@@NorthcoasterHobby Thank you very much and I will be looking forward to the results. Another thing during testing is position the folded dipole test 1 facing vertical like was showed in the video and test 2 facing down flat.
Can multiple folded dipoles, transformed to 75ohms be connected to a combiner then connected to the tv? I have a terrible time getting ch 2 in Houston area because I’m pretty much due north of the tower(s) and the entire South facing wall of my house is all solid. No windows. So I’m gonna have to go outside. I’ve tried “amplified” antennas and various models but the cheapest, passive one seems to be working the best. But channel 2 is awful. I added a length of coax and have my cheap antenna on the fence facing south - and it’s still glitching regularly.
I’m about 7 miles from the towers in my area. I’d say a homemade antenna like this might be good for 15-20 miles, give or take, under ideal reception conditions. No antenna will capture TV signals from 200 miles away. The curvature of the earth restricts reception to a maximum of 70 miles. Have you considered FTA satellite? TV Channels on Satellite 99.2 West KU Band Galaxy 16 - FTA Satellite TV th-cam.com/video/74ATpYK84x4/w-d-xo.html Getting Free Satellite TV th-cam.com/video/qBOVmYHAGWc/w-d-xo.html
To simplify it 4 everyone without all the half wave talk & confusing math! Just make it 3 ft wide & it covers all highband 7 thru 13 channels being used! It will be useful for about 40 miles
Which is it: 3 ft total or per each side?! Also most of the links said to be in the description link are either dead or simply not there. Also Northcoaster, if you see this comment and have the time to respond, of all the different antennas, shapes, lengths, etc., which one do you think is the best for receiving from VHF channel 12 all the way up to the end of the UHF band?!
@@panagdimi I used an 8 foot piece of copper tubing. Marked it 2 feet in from either side. Bent the radius at the 2 foot marks. So the top and bottom are each about 4 feet. The TV channel frequencies link must just have gone bad. Or the website is having problems. I just visited that link less than a week ago and it was working fine. There are many different antennas that will work, but it really depends on your location, among other factors. Some antennas are simply better than others. Have a look at my TV antenna reviews playlist for starters: TV Antenna Reviews th-cam.com/play/PLDX6gLCL4WMwMAycjBF3_ApXyAfwHNV4f.html If you’re looking for some High-VHF/UHF antennas (they cover RF channels 7-36), a few specific ones I have reviewed recently are: Televes V-Zenit MIX Outdoor TV Antenna Review Model 149381 th-cam.com/video/_f3V06kNhpE/w-d-xo.html Televes Ellipse Mix Outdoor TV Antenna Review Model 148883 th-cam.com/video/veWVeJkJscA/w-d-xo.html RCA Amplified Outdoor/Attic 'Spiral' HD TV Antenna Review Low VHF, High VHF and UHF Model ANT860EV th-cam.com/video/uxl_KoThg7E/w-d-xo.html RCA Outdoor Attic Yagi TV Antenna Review Model ANT752E ANT754E th-cam.com/video/ZzLy0hVlIk8/w-d-xo.html GE Pro Outdoor Yagi TV Antenna Review - OTA Television th-cam.com/video/pGJJLFdPRSg/w-d-xo.html RCA Attic Outdoor OTA TV Antenna Review Model ANT705E th-cam.com/video/st0LJK1Ia78/w-d-xo.html I hope this information helps. Thanks for watching my channel!
I don’t have any UHF channels in my city. VHF is still widely used here in Canada. But a UHF antenna would have an element of much smaller length. For example an antenna tuned to channel 14 (473 MHz) would have a folded dipole roughly 11 inches across, 23 inches in total length. www.changpuak.ch/electronics/Dipole_folded.php otadtv.com/frequency/index.html
Must be the old analog days 2 is no longer a tv TV channel unless its a virtual number. Most TV stations broadcast on UHF regardless of their number on the dial. We in Florida have a UHF channel broadcast on high VHF. Go figure. 73
Need to better understand how to determine the length of each side of the dipole based on the channels to receive. But technically do you need a separate length for each channel that is not practical. The TV band is channel 2 VHF all the way up to channel 36 UHF I believe the range is from 54 all the way up to 608 MHz. Can one antenna receive every channel in this range I'm not sure how you do that can you help?
DESDE URGUAY ,,MONTEVIDEO QUE PENA QUE LOS SUBTITULOS ESTE TAN CHICOS .. ASI MUCHAS DE LAS PERSONAS QUE USAMOS LENTES ,, PODRIAMOS LEER LAS EXPLICACIONES Y NO YO MUCHO DE NOSOTROS DESPUES DE LOS 60 AÑOS NO TENEMOS BUENA VISTA Y MAS PARA LA NUEVA GENERACION QUE LAMENTABLE,,MENTE TAMBIEN USAN GAFAS A ELLOS SE LES HACE DIFICIL LEER LOSSUB TITULOS EN LETRAS TAN PEQUEÑAS GRACIAS POR LA DEMOSTRACION DE ESTAS ANTENAS ,,10 4 2O23 ..
Thats all theory ! But without proper test equipment , you're relying on faith that this antenna is what you say it is ! I believe you have over complicated things for yourself, when a folded dipole offers greater bandwidth, essentially lowering the antenna " Q " ! Where as a typical half wave dipole can brought to resonance, with an input impedance near 73 ohm's, making it a perfect candidate for using 75 ohm shielded Coaxial cable, with no need for a transformer ! IMHO 🤔....? JUST SAY'N !
Thank you for your comments. It’s a DIY antenna, and I’m not an RF engineer. I added the balun to make it easier to connect coaxial cable. It gets the job done for me though.
@@NorthcoasterHobby Nor am I....lol ! Just from what I " Think " I've learned thru the years ! Your point is valid, and who can argue with success ? Many years ago, when this whole Off Air business took flight, a sight impaired Buddy of mine, and I were trying to pick up pictures for his wifes under the counter Tv ! So just experimenting, we had a paper clip pushed into the back of the TV, and wires connected to alligator clips, and had a pretty successful scan of the channels ! I spotted a connection I didn't like, and encouraged my friend to let me fix what I thought once repaired, may get us even more channels ! As I began to disconnect the mess of wires, I noticed the picture quality didn't seem to suffer ! This continued down to only the paper clip ! Just for grins, we did another scan, and ended up with something like 38 channels, with only a paper clip ! At the time, it was an unbelievable result ! Of course we laughed like kids, not believing what we just witnessed ! I tried to get my friend to make a TH-cam spoof out of this, but couldn't get him to do it ! I think it would have went well ? So much for our 15 minutes of fame ! Lol ! So you just never know ? He just happened to live in a very RF rich environment, I guess ? But I commend you for experimenting ! To me that's what it's all about ! Sorry if I came out of the gate a little strongly ! Congratulations on your antenna ! But one last parting shot ! I wonder if you have ever thought of connecting an amplifier to the antenna ? Some places it can help, and then others, I think it can cause issues ! Just wondering ! Thanks ! 👍😉
@@sleeve8651 It’s all good, I appreciate your input, thanks for sharing your experiences. A paper clip- some markets have strong enough signals to pull it off- I’ve seen it before on TV displays in stores!
Thanks to you, I made one of these antennas. I am soooo pleased. I am getting 4 and 5 of 5 bars. I am lucky that my towers are east or west of me, so this style works perfectly for my location. Total cost of new 1/4" x 10' copper tubing and transformer, $17
Excellent, glad you made one and it’s working well for you! Thanks for watching!
1) Both antennas should be 1/2 of a wave length.
2) The spacing between the arm with the transformer and the folded section matter to the performance. If you get those the right distance, the folded dipole has a wider bandwidth than the plain dipole. A pipe having a larger diameter than a wire also makes the bandwidth wider.
3) Your idea of impedance is correct. It works best when the impedance is matched. This also means that the resulting impedance is at zero phase. With a zero phase on the impedance (also call resistive), the voltage and current stay in step with each other.
Thanks Mr. I'm gonna make a folded dipole tuned for my favourite fm radio channel. Probably use a piece of square plastic from a discarded porch railing railing. (Non-conductive even when wet)
You’re welcome, thanks for watching and best wishes.
The folded dipole is the same length as a simple dipole. L (ft) = 492 / f ( MHz ). The characteristic impedance (Z) of a simple dipole several wavelengths above ground is 72 Ohm. It can be fed directly by 75 Ohm coax. A matching transformer 300: 75 ohm is unnecessary and will only cause signal loss. Folded dipole construction depends on the conductor diameter, spacing between the conductors, and the dipole length. Shape of the ends makes no difference. Characteristic impedance of the folded dipole is typically known as 300 Ohm. In practice however it is 200 Ohm therefore a matching transformer is needed for a coax downlead.
good job and creative use of copper tubing.
Thanks for watching!👍
I am trying to build one of these and have trouble physically adjusting the lengths of the dipole to the frequency I want. The thing that makes F.Ds work without being the exact right length is because the folded dipole is very wide banded, so if you get close, it will still be an improvement. A regular dipole has to be cut closer to the correct resonant freq. Also, your signal strength should be higher if you run that old 300 ohm tv twin lead wire all the way from the antenna and put the 4:1 300/75 ohm balun transformer at the bottom before tv. That old twin lead has 1/4 the signal loss of coax. If you cut antenna elements exactly right length, it will be even stronger, but you will need a $45 NanoVNA antenna analyzer to do it.
Since it does a good job receiving VHF Low it will also receive FM channels but for both FM and DAB+ the antenna must be mounted vertical.
For sure, just have to mount it sideways!
@@NorthcoasterHobby For FM reception in order to receive most of the channels and in stereo you must mount it sideways otherwise you have to rotate the antenna each time you search a channel. In Europe most countries broadcast FM vertical so the antenna mounted horizontal will do a poor job. DAB+ can only be received vertical.
If the antenna is mounted at a 45-degree angle, halfway between horizontal and vertical, it will receive each polarization at 70 percent strength (cosine of 45 = ,707). Losing 30 percent of a signal is rarely a problem; if it truly is, buy a second antenna, some cable and a switch. That way, you can choose between a horizontal or vertical antenna at the receiver. Radio/TV hobbyists nearly all have more than one antenna. Anyone can do it.
@@bloggerccc In my case for FM I installed a 3 elements Yagi antena vertical mounted, for VHF High (DAB+) I installed a 7 elements Yagi antenna vertical mounted, and for UHF a 19 elements Yagi antenna horizontal. An FM+VHF+UHF combiner and a 4 output amplified splitter. I have excellent reception on both TV and radio (FM and DAB+). I prefer to install multiple antennas to get the best reception.
Sometimes these simple designs work surprisingly well. I'm much further from the towers, so multiple similar dipoles are needed. Hence Channel Master 4221. That design has been copied longer than I've been alive.
Hi good video, thanks. What are you using to measure the signal strength? Thanks
To measure the signal strength I’m using a digital converter box. Most of them have a built-in signal meter.
Core Innovations OTA Digital TV Converter Box DVR Review - DTV Converter Box with PVR Recording
th-cam.com/video/TK4IUDi83r0/w-d-xo.html
I'm not clear on how dipole antennas are supposed to be aimed - should the elements point at the broadcast tower or be perpendicular to the tower? Helpful video but I'm going to try your simple non-folded one first.
@@MrYu2ube the wide part of the antenna faces the broadcast signal.
"I kinda spitballed it". 🤣😂 yea, I made a couple of antennas myself, a two and four bay bow tie, and a gray-hoverman. I wish you had some UHF stations available. would be interesting to see if this folded dipole model could pick up UHF.
Indeed it would be.👍
Improve performance of this antenna. Your overall length should be 104 inches. About 8 ft. Granted not ideal, but you aren't getting the most gain or efficiency with the shorter length. It's a wonder you are receiving. As is each side is 1/8 wavelength long. Ideal construction would be found in an antenna handbook. But when I build these I use lengths of 300 or 450 ohm flat or ladder line. The spacing is already set. Split one side at the mid point and solder your transformer or another length of your line one to each side. As in common FM stereo antennas. You get improved gain (around 3 dbd) and bandwidth. You may do as well with a fan dipole and easier construction, as you aren't transmitting. Or just use an folded dipole antenna made for fm stereo. I applaud your building efforts. I hate that everyone wants to buy lower quality when they could build better for free. Keep it up.
An ideal antenna will be about 1/4 wavelength on each side, not 1/8th as you suggest.
@ToddCarpenter-N9YSQ and Northcoaster Hobby. I made a Folded dipole antenna a few years ago to pick up channel 4 in my area (used a stripped down electrical cord). It was a full wave antenna, so it is rather large in my opinion. I just stumbled upon this video and see the success with the half have folded dipole. I just tried to make a half wave to pick up channel 4, but didn't have any success. Do you have any thoughts or advice as to why it isn't working? I realize you can't see it, but I am using speaker wire this time (for testing purposes). I need to make an antenna for someone to pick up channel 12 (real broadcast channel) and I would like for it to take up as little space as possible. Being a novice, this Half Wave Folded dipole appears to be the only option, if I can get it to work. Also, the diameter of wire or tubing that is used for an antenna, I presume that the large the diameter of the wire or tubing helps in better reception? Thanks for posting this video and for your reply.
@@kensmith5694No, Todd is saying that the Channel 2 antenna in this video is only 1/8 wavelength on each side .
@@Fetherko Read my comment again. I said the size for an ideal antenna and not for this less than ideal one
It's about resonance. Resonance happens best on full wave, 1/2 wave, and 1/4 wave. You actually get a bit of gain if you make a full wave x1.25 length.
Awesome vid! I was hoping you would compare the double dipole to the simple dipole for the Hi VHF range - I have wanted to understand whether there is benefit to a double dipole of full wavelength length in comparison to a single dipole of half wavelength length.
@@spirahsass Here are a couple of simple dipole antennas I made. You can see the signal levels for each for comparison.
Build a Homemade DIY TV Antenna from copper wire - dipole OTA TV antenna for local channels
th-cam.com/video/bYfZu923aTY/w-d-xo.html
How To Make a Simple DIY Homemade Dipole TV Antenna - get free OTA TV Channels
th-cam.com/video/6tqQkylXZFM/w-d-xo.html
Thanks for visiting my channel.👍
@@NorthcoasterHobby thank you! I just discovered your channel and I’m learning what I can!
@@spirahsass 👍
You can't beat the eggbeater antenna in Florida. It cannot be beaten even with a stick I tell yaoiuns!!
Since I live in an area where Low VHF channels are plentiful. And the dipole needs to be so large in size to receive the signals accurately. Would making the antenna folded on itself two time instead of your one fold making the antenna a smaller footprint help increase the gain of the signal Sir ?? Thank you for your video Sir. Nice work with honest information for one to learn from.
Peace vf 😀😀😀😀😀
@@victoryfirst2878 I would not do that because you want to maximize the amount of signal that the antenna grabs. Low-VHF wavelengths are long. So either use a folded dipole like this or long dipoles (unfolded),
@@NorthcoasterHobby I understand what you said Sir. Would making the antenna say 1.25 larger than the standard wavelength increase the reception ?? I read on WIKI using the slight larger size increases the signal gain ?? Reason I am asking as the WIKI article on dipole states the the 5.2 directive gain is achieved by what the author stated.
Thanks Sir.
@@NorthcoasterHobby Would using the wire length of 1 1/4 times the frequency wavelength give you a 5.2 directive gain dBi ?? How about folding the loop a few times to reduce the width size keep the gain the same ?? What I mean is the ends are S and a half shaped. Thanks vf
Resistance is when current or voltage is restricted in a Direct Current (DC) circuit
When resistance is applied to an Alternating Current (AC) circuit, it's called impedence. Radio waves are electro-magnetic AC, so we talk about impedene at antenna feed points.
Antenna dimensions are criitical for transmitting so your rig doesn't melt. For only receiving, the math is not so critical.
Build one and try it.
Thanks for the information.👍
Resistance is a measure of voltage divided by current in a resistor. Impedance is the generalized notion of voltage divided by current for any component.
my FM radio has only 1 antenna out. (single wire). but coax has two wires , outter earth and inside copper.
Use a 6:1 Balun instead of the transformer and you get a good connection to 50 Ohm coax, with a minor adjustment to the length it will now work as a transmitter antenna in the Amateur 70 MHz band.
So changing the transformer to the balun you suggested turns this into a Ham Radio antenna?
Cool!
Is that 6:1 balun something that can be bought or built?
Does Ham Radio use 50 ohm coaxial?
@@NorthcoasterHobby Yes. Almost all Ham transmitters and receivers have 50 ohm output/input impedence and use 50 ohm co-ax to the antenna. 6:1 baluns can be bought or a look at the ARRL or RSGB websites will show you how to make your own. Your choice. They are so cheap it's hardly worth the effort. Your local ham radio store will have them in stock.
Ian G4JIU
Where are you getting the lengths for the dipoles? I get much shorter lengths when I look them up
As I said in the video I used an 8 foot piece of tubing and bent it around a radius to get a folded dipole of about 4 feet. RF channel 2 requires dipole elements of about 8 feet (4 feet each), so I figured that would be close.
I've made antennas for cb and 10meter freeband back in the day. I currently made a simple uhf loop just to see what channels would come in. I was amazed to see 95+ channels come in! Most signal ratings are between 50-75% . My older Tv (still flat but older tuner) doesn't seem to tune all digital channels. I think I'll try this vhf dipole and see what happens. My Tv doesn't show the frequency...just shows channel numbers like 5.1 ,5.2, 5.3...ect
Nice link, thank you!
Could you make this antenna work for OMNI directionality and deep fridge distance ?""
To make this a deep fringe antenna would require adding a long boom, longer elements(several more), as well as several director and reflector elements.
I suppose to make an omnidirectional antenna you could form the metal into a loop and orient it horizontally.
@@NorthcoasterHobby Would you have an plan that I can go by to make me one Northcoaster Hobby ??? What I need is a ultra deep fringe omni-directional antenna. I am sure I could make me one that has been proven with just a plan from you Sir.
Thanks too.
Could you do the same thing but with TWO dipoles? Like one above the other, and both connected to the balun?
I would put a balun on each antenna. That’s the proper way. Then combine the antennas with a diplexer or A/B switch.
@@NorthcoasterHobby - would that effectively improve your reception, or would it be a minimal improvement?
If you are suggesting what I think you are suggesting, the answer is "it won't work very well. A simple 1/2 wave dipole tends to have an impedance of no more than 73 ohms. If you do two of them both connected to the same transformer, you will have an even lower impedance. Thus the balun intended for 300 ohms will be badly mismatched.
@@kensmith5694 - thanks for the reply. I don't know much about the electronics involved, so I'm just trying to figure out a system that might work well for me. Are there other baluns that would handle that better, or are they all a standard 300 ohms?
@@doplinger1 The 300 to 75 Ohm balun is the one you are likely to find out there. Other impedances can be made but there isn't much market for them. A good first step for you is to find out the RF frequencies that are going to matter to your antenna. There are sites out there that will take your location and tell you the stations you might get. On some of them, you can see frequency directly. On others they tell you the "RF Channel" that you then need to go look up to find the frequency.
If all the "xxxMHz" numbers cover much less than a 2:1 range, a folded dipole may very well work for you.
Like to see try out my home made antenna single six foot dipole works great because it's all directional made out of the same material you're using now
Do you have a video about it?
@@NorthcoasterHobby I've never put a video on TH-cam before give me a few weeks and I'll make one thanks for the interest
@@sherrilmason1195 👍
How far away from the Tv towers are you? Im over 200 miles away from any Tv tower! Will it work ?
I’m about 7 miles from the towers in my area. I’d say a homemade antenna like this might be good for 15-20 miles, give or take, under ideal reception conditions. No antenna will capture TV signals from 200 miles away. The curvature of the earth restricts reception to a maximum of 70 miles. Have you considered FTA satellite?
TV Channels on Satellite 99.2 West KU Band Galaxy 16 - FTA Satellite TV
th-cam.com/video/74ATpYK84x4/w-d-xo.html
Getting Free Satellite TV
th-cam.com/video/qBOVmYHAGWc/w-d-xo.html
Double penny loop works better than a folded dipole in my experience. You can go full wave x1.25 length with some conductive copper tape in your attic.
Thanks for the tip 👍
No idea what the double penny loop is
Thank you Northcoaster Hobby for making this video about Folded Dipole and if you Northcoaster Hobby still have that folded dipole antenna for Channel 2 can you test it indoors? I'm curious to know if it's possible to receive low vhf channels 2-6 using single 300 ohm folded dipole antenna cut for the frequency. Alexander 98.
I still have it. I’ll try it out sometime. The indoor reception of RF channel 2 varies greatly from season to season. Winter is usually better for indoor reception for me on account of the trees have no leaves. Thanks for watching!
@@NorthcoasterHobby Thank you very much and I will be looking forward to the results. Another thing during testing is position the folded dipole test 1 facing vertical like was showed in the video and test 2 facing down flat.
Can multiple folded dipoles, transformed to 75ohms be connected to a combiner then connected to the tv? I have a terrible time getting ch 2 in Houston area because I’m pretty much due north of the tower(s) and the entire South facing wall of my house is all solid. No windows. So I’m gonna have to go outside. I’ve tried “amplified” antennas and various models but the cheapest, passive one seems to be working the best. But channel 2 is awful. I added a length of coax and have my cheap antenna on the fence facing south - and it’s still glitching regularly.
You can certainly try that. Use a combiner, also known as a ‘diplexer’. Let me know how it goes.
nice results
I am quite pleased with the results; it’s fun making antennas, especially when the they work this well. Thanks for watching!
I live in Wyoming 200 miles away from any tv towers.Will it work or not? You didnt say what mile range it is! Is it for 150 miles or 1mile? 😮
I’m about 7 miles from the towers in my area. I’d say a homemade antenna like this might be good for 15-20 miles, give or take, under ideal reception conditions. No antenna will capture TV signals from 200 miles away. The curvature of the earth restricts reception to a maximum of 70 miles. Have you considered FTA satellite?
TV Channels on Satellite 99.2 West KU Band Galaxy 16 - FTA Satellite TV
th-cam.com/video/74ATpYK84x4/w-d-xo.html
Getting Free Satellite TV
th-cam.com/video/qBOVmYHAGWc/w-d-xo.html
Doesnt say if its a long distance or a local antenna?
Probably good for 15-20 miles under ideal conditions. Did you see my other replies?
Can I use that transformer on a long range antenna I found in my attic?
If it doesn’t already have one , then yes.
To simplify it 4 everyone without all the half wave talk & confusing math! Just make it 3 ft wide & it covers all highband 7 thru 13 channels being used! It will be useful for about 40 miles
There’s a theory behind antenna design. But your method will work too! As I said in the video I sort of spitballed this one.
Which is it: 3 ft total or per each side?!
Also most of the links said to be in the description link are either dead or simply not there.
Also Northcoaster, if you see this comment and have the time to respond, of all the different antennas, shapes, lengths, etc., which one do you think is the best for receiving from VHF channel 12 all the way up to the end of the UHF band?!
@@panagdimi I used an 8 foot piece of copper tubing. Marked it 2 feet in from either side. Bent the radius at the 2 foot marks. So the top and bottom are each about 4 feet.
The TV channel frequencies link must just have gone bad. Or the website is having problems. I just visited that link less than a week ago and it was working fine.
There are many different antennas that will work, but it really depends on your location, among other factors. Some antennas are simply better than others.
Have a look at my TV antenna reviews playlist for starters:
TV Antenna Reviews
th-cam.com/play/PLDX6gLCL4WMwMAycjBF3_ApXyAfwHNV4f.html
If you’re looking for some High-VHF/UHF antennas (they cover RF channels 7-36), a few specific ones I have reviewed recently are:
Televes V-Zenit MIX Outdoor TV Antenna Review Model 149381
th-cam.com/video/_f3V06kNhpE/w-d-xo.html
Televes Ellipse Mix Outdoor TV Antenna Review Model 148883
th-cam.com/video/veWVeJkJscA/w-d-xo.html
RCA Amplified Outdoor/Attic 'Spiral' HD TV Antenna Review Low VHF, High VHF and UHF Model ANT860EV
th-cam.com/video/uxl_KoThg7E/w-d-xo.html
RCA Outdoor Attic Yagi TV Antenna Review Model ANT752E ANT754E
th-cam.com/video/ZzLy0hVlIk8/w-d-xo.html
GE Pro Outdoor Yagi TV Antenna Review - OTA Television
th-cam.com/video/pGJJLFdPRSg/w-d-xo.html
RCA Attic Outdoor OTA TV Antenna Review Model ANT705E
th-cam.com/video/st0LJK1Ia78/w-d-xo.html
I hope this information helps. Thanks for watching my channel!
What about UHF channels?
I don’t have any UHF channels in my city. VHF is still widely used here in Canada. But a UHF antenna would have an element of much smaller length. For example an antenna tuned to channel 14 (473 MHz) would have a folded dipole roughly 11 inches across, 23 inches in total length.
www.changpuak.ch/electronics/Dipole_folded.php
otadtv.com/frequency/index.html
@@NorthcoasterHobby Thanks!
A simpler version is this:
Build a Homemade TV Antenna from Coaxial Cable - DIY OTA TV Antenna
th-cam.com/video/ACWdzkHSVXE/w-d-xo.html
@@seanedwards569 👍
could this antenna reach 500m
Do you mean metres or miles?
@@NorthcoasterHobby meter
@@NorthcoasterHobby also i meant for transmitting not recieving
@@ventinator0 Definitely would reach 500 metres!
IF IT IS 600 FEET HIGH IT MIGHT, REMEMBER THE EARTH CURVES
WOW
Must be the old analog days 2 is no longer a tv TV channel unless its a virtual number. Most TV stations broadcast on UHF regardless of their number on the dial. We in Florida have a UHF channel broadcast on high VHF. Go figure. 73
All my channels are digital. OTA TV broadcasts from RF 2-36. However the majority of channels are broadcast on UHF 14-36. 73
Need to better understand how to determine the length of each side of the dipole based on the channels to receive. But technically do you need a separate length for each channel that is not practical. The TV band is channel 2 VHF all the way up to channel 36 UHF I believe the range is from 54 all the way up to 608 MHz. Can one antenna receive every channel in this range I'm not sure how you do that can you help?
DESDE URGUAY ,,MONTEVIDEO QUE PENA QUE LOS SUBTITULOS ESTE TAN CHICOS .. ASI MUCHAS DE LAS PERSONAS QUE USAMOS LENTES ,, PODRIAMOS LEER LAS EXPLICACIONES Y NO YO MUCHO DE NOSOTROS DESPUES DE LOS 60 AÑOS NO TENEMOS BUENA VISTA Y MAS PARA LA NUEVA GENERACION QUE LAMENTABLE,,MENTE TAMBIEN USAN GAFAS A ELLOS SE LES HACE DIFICIL LEER LOSSUB TITULOS EN LETRAS TAN PEQUEÑAS GRACIAS POR LA DEMOSTRACION DE ESTAS ANTENAS ,,10 4 2O23 ..
Sí, los subtítulos son bastante pequeños, desearía que hubiera una opción para hacerlos un texto de mayor tamaño. ¡Gracias por ver mi vídeo!
Thats all theory !
But without proper test equipment , you're relying on faith that this antenna is what you say it is !
I believe you have over complicated things for yourself, when a folded dipole offers greater bandwidth, essentially lowering the antenna " Q " !
Where as a typical half wave dipole can brought to resonance, with an input impedance near 73 ohm's, making it a perfect candidate for using 75 ohm shielded Coaxial cable, with no need for a transformer !
IMHO
🤔....?
JUST SAY'N !
Thank you for your comments. It’s a DIY antenna, and I’m not an RF engineer. I added the balun to make it easier to connect coaxial cable. It gets the job done for me though.
@@NorthcoasterHobby
Nor am I....lol !
Just from what I " Think " I've learned thru the years !
Your point is valid, and who can argue with success ?
Many years ago, when this whole Off Air business took flight, a sight impaired Buddy of mine, and I were trying to pick up pictures for his wifes under the counter Tv !
So just experimenting, we had a paper clip pushed into the back of the TV, and wires connected to alligator clips, and had a pretty successful scan of the channels !
I spotted a connection I didn't like, and encouraged my friend to let me fix what I thought once repaired, may get us even more channels !
As I began to disconnect the mess of wires, I noticed the picture quality didn't seem to suffer !
This continued down to only the paper clip !
Just for grins, we did another scan, and ended up with something like 38 channels, with only a paper clip !
At the time, it was an unbelievable result !
Of course we laughed like kids, not believing what we just witnessed !
I tried to get my friend to make a TH-cam spoof out of this, but couldn't get him to do it !
I think it would have went well ?
So much for our 15 minutes of fame !
Lol !
So you just never know ?
He just happened to live in a very RF rich environment, I guess ?
But I commend you for experimenting !
To me that's what it's all about !
Sorry if I came out of the gate a little strongly !
Congratulations on your antenna !
But one last parting shot !
I wonder if you have ever thought of connecting an amplifier to the antenna ?
Some places it can help, and then others, I think it can cause issues !
Just wondering !
Thanks !
👍😉
@@sleeve8651 It’s all good, I appreciate your input, thanks for sharing your experiences. A paper clip- some markets have strong enough signals to pull it off- I’ve seen it before on TV displays in stores!