This is an excellent and very detailed video. I appreciate the time and effort you put into it. A few years ago I made a dipole by enclosing copper wire inside 1/2" PVC pipe. However, it was cut to one frequency so changing frequencies is not possible. I used a washer on each end of the pipe, inserted a zip tie through the washer and secured it to the end of the copper wire so it would not collapse inside the PVC pipe. Next, I capped each end and sealed all holes and mating surfaces. I did not consider the VOP through PVC pipe because it was not necessary for my needs. I only wanted it to reach my garage, but during my first test, I found that it would reach 1.5 miles with a half a watt. I really enjoy building my own antennas. I found that it is fairly easy to have a great antenna without spending a lot of money.
Funny that you should mention your homemade antenna with PVC pipes. I have been considering making a video about making the cheapest antenna ever using PVC etc. The tuning part is where I got stuck. I have tried many variations on it to make it tunable but not too much success yet. I have almost solved it but it's still in the making lol. I will post it as soon as I am happy with the design. The problem is that the kind of PVC that is useful can be almost as expensive as thin aluminum. If you do it right aluminum and spring steel like flexible antenna rods are cheaper and make the antenna tunable. Oh by the way, yes 0.5 of a watt is actually a huge amount of power. If high enough it can reach up to 7 miles. You need as little as 0.05 watts to reach your garage. Thanks for your comment. Always fun to chat about these things.
@@inspiresoundpro I prefer aluminum but PVC is very cheap and very easy to get where I live. The downside is not being able to tune for another frequency, the upside is I get to build another antenna! I have built several. Some are just for receiving and they work great. Unfortunately, many FM stations here are owned by just a few major corporations using very similar formats. Originality is nonexistent. When I tested the range, it was with the antenna standing in a corner inside my house. I never mounted it. Actually, since it was far more capable than needed, I only used it one day out of the week while I was working outside. I subscribed to your channel. I like the content and look forward to your next build.
Hey, thanks for the sub. I'm glad you like the videos. I am busy working on a quarter-wave design. It's a bit more difficult to build than the half-wave dipole but it's great for an omnidirectional signal. Dipoles are a bit directional. I will post it when it's ready. Cheers
Thank you mr.radio God for all that mumbo jumbo. Now put down your bongs it's time for class. If you have a licensed full power fm station you don't build a complex setup like described here in the previous comment. Fine if you just enjoy playing with wire but not a real world solution. Let's start with the dipole because I have some issues with that. There's a chart available free online for determining the length of the radials and I personally wouldn't use aluminum I would use copper. You shouldn't need more than 2 , 8 foot lengths of half inch copper pipe. Following the information on the chart for your frequency and power level carefully measure,( measure twice cut once) you will need a connector for 50 ohm coax and a 50 feet run of said coax and the connector should be female for attachment to the coax and the other end of the connector should be open so you can solder 2 , 6 inch pieces of number 12 stranded wire, one to the center conductor and one to the outer conductor. A simple round 4 pole pull box will be the center of the antenna. You will put one radial up and it goes to the center conductor and the other down going to the other conductor. To one side you cap off the port because it won't be used and the other remaining port you put a three quarter inch 90 pointing down and you put another 90 into it opposite of its direction.you then put a capped and trimmed slightly longer than your radial, three quarter inch PVC over the upper radial and an identical length pipe with a cap on the bottom but drill a small hole in the bottom cap so any water that may get in can drain. In the video a crossover plate was used to attach to the vertical pipe,( pole) but instead you use what's called a pipe to pipe bracket,( also available at home improvement stores) and that way you have several degrees of down tilt available to fit into your contour. This setup shouldn't cost more than $50 for everything except the coax from your transmitter to the antenna. To pre adjust the swr simply with transmitter on move the radials to and from each other until you get around 6 db. Once you've installed the antenna you can both alter your power and mechanical down tilt to avoid over modulation and exceeding your contour. For less than $250 including the transmitter you have an fm station that at one miliwatt should easily transmit 15 miles or more and as long as you keep your swr around 6 you shouldn't have wonky wave or distortion. Commercial stations don't build their own antennas they buy them from companies like Harris or dielectric or radio frequency systems. If you aren't getting the swr you need at power then you can add another identical antenna above or below and run them from the same transmission line but you will need a 50 ohm T connector and a jumper coax to supply the second element. Thus creating an array. The second element and connector shouldn't insert enough loss that you can't compensate for by adjusting power level. Keep it simple stupid. All those amplifiers and multiple lines coiled up, I've been doing this for 29 years and never have I seen anything like that. Not on commercial stations or lpfm. There's a million ways to do anything but why make it complicated and expensive?
30 year plus veteran broadcast engineer here, let me see your breakdown of these antennas is quite good. This video actually serves two purposes one to explain in layman's terms what's going to happen. And also the technicians that get too deep into the engineering., I have seen some antenna Rays with as many as 16 circular polarized dipoles stock at one wavelength apart, taking up most of a 400 ft tower. All being fed using Ridgid cable. I've also made them with rg59 coat hangers and PVC pipe. The only limiting factor is rg59 can only withstand about 100 watts. In that case we would use rg11, which can handle approximately 500 to 1000 watts. Usually we design each dipole to handle 50% of the total power will be feeding into the system even if it's a four-way system, will still design them to take usually around 400 watts each. I've also seen systems, where you have four dipoles on the tower. The cables on them are all long enough to reach the ground. And then all of the same length. Each dipole is connected to the output of a separate power amplifier, the inputs to the power amplifier are generated by a divider Network after the exciter. Essentially the phase splitting and alignment, is done at the input of the amplifiers has the amplifiers do not add significant phase shift. This can't be said for all amplifiers. But in most cases the modern solid state ones can do this. It's actually possible to obtain 100,000 watts effective radiator power using only 10kw of amplifier. Each dipole, is built into 50 ohm antenna. All the cables are exactly the same length of 50 ohm coax. And yes this uses hundreds of feet of coax to do this. You must have the same length at the Top Antenna as at the bottom antenna then all the cables are ran back to the transmitter. Where you would have the output of 10 seperate power amplifiers. Each power amplifier feeds one antenna.. the input of each amplifier, comes from a power divider network. Essentially the same thing you're building for the antennas with coax, you build a smaller version that stays down with the amplifier. The beauty of the system is that it's easy to install you just roll up the excess coax and cable tie it to the tower. Once you have all the antennas spaced on the tower and everything is ready to go. With the multiplied gain of 10 dipole antennas, we're being effective radiated power of 100,000 watts. The true beauty in the system. Is that should you decide you want a small amount of beam tilt, either up or down it's going to be accomplished by just changing the length of the coax feeding the power amplifier to that antenna. And up or down beam till is easily added
Wow it's always great to hear about the big installations and to hear from broadcast industry professionals. So thanks for your input. I unfortunately never got work on such big set ups. It's even difficult to comprehend that kind of power and all the issues that go with it. In most of my set ups if it went wrong the transmitter would go into safe mode until you fix the problem with no real consequences but at your power levels it's a whole different ball game. The cost as well in a completely different league. I think the majority of my viewers will never encounter set ups like you have worked on so always interesting to get some input about it. Thanks for you nice compliment. I do try my best to make my videos as accurate as possible while making them as understandable for everyone as possible. The majority of my viewers are first timers so I try to make the information as accessible as possible. Thanks again for your input. Always appreciate getting feedback from professionals. Cheers :)
@inspiresoundpro just because the power levels go up, the system only gets more complex due to the size of the components used. However there are several of these antenna systems that are described using multiple amplifiers and multiple dipoles, sold by a company out of Latin america. It's actually a very ingenious system as you don't have to have crazy Tower mounted power dividers. They use basic diapers made of aluminum tubing with a plastic Center insulator. I believe they feed them with LMR 600. The number of feet per antenna Escapes Me Right now, but the system is somewhat built to order so that they can optimize the cable length however all cables are of equal length. And then it uses a stack of multiple 1 KW power amplifiers. Most modern FM transmitters even from the cheap ones sold on Amazon up to the biggest commercial units all have powerful back at SWR protection. As the broadcasting industry we have issues with our basis. It could be anything from a lightning strike, to birds deciding to building a nest on the feed point. And he has to be our becomes unstable. Or in one case there was a gasket missing on the feed line, and the entire feed line filled with water. I had drill 1/8 inch hole at the lowest point in the system and had water pouring out, also being pushed out by the nitrogen gas we use to pressurize the cable. However the nitrogen have been turned off for several weeks, during the winter time when we had heavy rain and storms. So the cables ended up filling up with water. The only difference in low-power to high power are physically the size of the components their power consumption when you plug them in, and the height of the tower you need to get the antennas away from human beings to not cause problems. Also your harmonic filters need to be very robust and have sharp cut off. So that you don't cause serious interference. Your basic Broadband low pass filter that cuts off at 110 MHz is woefully inadequate. I would highly suggest anyone attempting to build their own transmitter or Exciter board. Do some research into the design of these filters. The fixed capacitor values, could be reduced slightly and then parallel with a adjustable trimmer capacitor. Thereby allowing the operator to tune out and know the second and third harmonic. As the current FCC standard requires your third harmonic to be 60 DB lower than your main carrier, it is hard to achieve that using a Broadband filter circuit tuned for just below the aviation band. Normally I would have a 5 or 6 Pole low pass filter mounted in a small chassis box on the Exciter, then good coax between the chassis box filter and the input of the FM amplifier. In some cases should have been a particularly dirty radio system with a lot of harmonic issues we would add an interstage filter you clean up the output of the Exciter feeding into the intermediate power amplifier. We found out by doing this we actually gained about 10% more output power then before, as we were cleaning up the signal before it went into the main power amplifier and was not as wide, therefore the amplifiers gain was all focused on one frequency rather than a broadband signal along with noise. Similar to you how 1,000 Watts on FM radio goes a lot farther than a thousand Watts on television. Because if television signal is 6 MHZ wide, so when you refocus the wide band signal to a narrow band signal you gain efficiency at higher output levels
I appreciate the graphical detail and wish other could use it along with real pics of what is going on. This is what information sharing is all about. Making it understandable.
Thank you. Yeah I try my best. It is difficult though to create these kinds of graphics so are not as common. The only other way is to use things like CAD graphics which is very unlikely. But I hope its clear enough. Thanks. Cheers :)
What about a balun for this antenna , what will be the gain for this antenna ? Thank you for the video , answering this questions will be helpful and good to improve the mach and performance for this antenna
Thanks for your questions. I have to laugh though because the balun question comes up every so often. It has been answered very well below in other comments but the short answer is no it does not need a balun especially if it's used only for transmitting. If you use it as a two way antenna or only for receiving then it might be useful but not necessary. The antenna has zero dB gain. Most quarter wave and half wave antennas have zero dB gain. If you stack them together in pairs or more you can Increase the gain. Check out my video on antenna arrays for that. This antenna is designed to be tuned so that is where the real benefit is . Cheers.
Thank you! I will be using this antenna to simply receive FM signals. How would I adjust the aluminum rods to tune it to a specific frequency? The video you recommend at the end titled, ‘FM Transmitter How To Build Circuit DIY Homemade’ does not explain how to tune (adjust the aluminum rods) on this adjustable Dipole antenna for maximum receiving of FM signals. Maybe I missed something. Thank you again. I like the way you explain the build process. Very clear and thorough!
You are very welcome :) Yes I have a video on how to tune antennas. My channel is mostly focused on transmitting but the same principles apply for receiving. Only problem is that to tune the antenna perfectly you actually need to run a transmitter into in to measure the return signal or you have to buy a fairly expensive antenna analyzer. The best option for receiver antenna is to simply adjust the antenna by physical length to as close to the signal wavelength as possible. The video to watch is this one : th-cam.com/video/WOGX70-kIYA/w-d-xo.html It is intended for transmitters so most of the tuning wont apply but it does explain how to calculate the antenna length using an online calculator.
Can I use this adjustable dipole antenna for simply receiving FM signals? All I want to do is receive a strong and clear FM signal on my FM receiver. In other words, is this adjustable Dipole antenna project ‘overkill’ for simply receiving FM signals or would I be better off simply building a fixed length basic dipole antenna? Thank you kindly for this DIY adjustable Dipole antenna project. Looks fantastic!
Thank you. I always enjoy it when people get some value form my videos :) Yes this antenna can work very well for receiving. It may be an overkill if you only want a slight improvement but if you are far from a transmitter like in rural areas then this antenna is great for that. You can also build a directional version but that would be way bigger and difficult to install. For transmitting and receiving this antenna, especially if you tune it to the frequency you want, will give a very strong signal.
@@inspiresoundpro Thank you. I am going to ask a different question and didn’t want to bury it here. This way others can see it more easily and learn from your answer. Thank you!
@@youtubecommentor4480 the sizes and sturdiness are overkill for listening to broadcast fm. I made a simple dipole of 1/8" solid copper wire and mounted it horizontally (broadcast fm is circular polarized) and it has exceeded expectations. Amazon sells small diameter nesting aluminum and copper tubes that would be great too. if you take a look at commercial outdoor antennas, they use 3/8" diameter elements or even smaller
You can make the wooden dowl stick longer but it will not change the strength because the strength comes from the bolts holding the aluminum rods to the box.
There are two opposing opinions about baluns for dipoles. For receiving antennas it can make a difference with reducing interference so if you use the dipole to receive or as a two way communication antenna then yes it can be useful but if it is purely for transmitting like this dipole was designed for then you don't really need one. I have run very low power and a few hundred watts with no balun and had great signals. The antenna tuning was more important. In many cases a balun, especially the wrong type of balun can hurt the signal more than help it. So there are differing opinions but for transmitters I have found it best not to use one.
The idea behind the design is that it can be adapted to the parts available to you. A range of box, bolt and aluminum tubes can be used. The dimensions given are the ones that work well together but the dimensions can be adapted to your size box and aluminum rods. Some people have even adapted the design to other frequency bands like Vhf and uhf. The idea is not for it to be a one size only design but rather a template to adapt to what you have available. The wavelength for FM band though means keeping the lengths of the rods the same but most other things can change.
I am really enjoying your videos. I dont know if its your wording or specifically how you explain things but your videos are very intuitive. Thanks for the content.
Thank you so much. It's really awesome to get your feedback. It can sometimes takes weeks to make videos and when I release them I don't know if I did it right LOL. Some succeed some don't. I guess I'm always learning. Even though I have experience in broadcasting and video I am quite new to TH-cam so there is always something new to learn. I try to make videos the way I would want to watch them so I try to solve problems the way I would need them solved for me so I think that's what makes it seem intuitive. Thanks so much for your feedback. It helps to keep going. Cheers :)
@@inspiresoundpro im sure your experience is a major player then. Knowing what is useful and relevant. I feel like no matter the field, even with professionals they often fall back to cookie cutter recipes and give no thought to the reason or know little about the nuances of what makes it work. Thats great of we bake the same cake in the same kitchen. But for the rest of us in our own kitchen, it is amazing to have teachers to teach us why the oven temperature is set the way it is.
Agreed. That's why I don't even try to do things other channels are doing. I think of what I would like to see and then I try figure out how it should be best explained. I find that if I am doing it correctly that I end up learning new things too as I go along because I need to be able to re-create the solution myself. If I just do generic solutions it's often not really of any help to anyone.
Hi. Thanks for your comment. Yes its true that it is commonly believed that a ballun is needed but in fact there are many engineers who believe that a balun is most likely to be done incorrectly and therefore would do more harm than good which is most likely when first time builders use one. The ballun can reduce some interference and match impedance but if the antenna is built correctly, tuned close to resonance, and installed correctly the ballan will most likely make no measurable difference to the transmitted signal. In two radio where the antenna is being used for transmitting and receiving then a ballun can be more noticeable but for a purely transmitting antenna which is what this design was intended for, a ballun is not really needed. I do appreciate your input though. Its always great to chat with people about this because it gives newcomers more insight into things they might not have heard of. And to add to this I ran a low power commercial radio station with a 1 Watt Fm transmitter and we did not use a ballun and the signal was fantastic. The reason is that the antenna was high up on a hill and tuned and installed very well. These things matter way more than a ballun. This is something I try to get my viewers to pay attention to more as it will dramatically affect their range. Thanks so much. Cheers.,
What is common to use a balance on HF frequencies, and VHF frequencies is not necessary, the dipole itself when Tim correctly should be almost a 50mm resistive load. So feeding it with a length of 50 ohm is perfectly acceptable. The phasing coax or power divider coax, it's usually made from 75 ohm, either rg11, or RG6 with Copper sheld, the point where the two interconnect, can be as simple as a basic coaxial t connector. Important part is to make sure that all of the coaxes are the same length. If one cable is even a few inches longer. It will cause the signals to not be in Phase when they leave the tower. You also have a high reflected power on your meter.
Thank you .Always great hear from people in the field. Yes as you said the idea of a ballun for all uses is not correct. In many cases the use of the ballun distracts people from paying attention to what you mentioned which can make a much bigger difference. Also I think some people think that the ballun fixes all problems which is not a good way to think. Thanks so much for your input. My viewers do seem to learn as much from the comments as the videos. Cheers :)
@allen_steel1236 ballun using not only to transform resistance. It is used as a bridge from an unbalanced coaxial cable and balanced dipole. If you connect them directly, there will be some standing waves on the body of the transmitter, and depending on how much power it can cause damage or errors on devices, connected to transmitter.
Hi. The pipes are all aluminium. Aluminum is just the way Americans say aluminium. It's the same thing. The measurements for the pipes are all in the video. Check out the beginning where all the measurements are listed. 300 Watts might be too much power for this antenna. It has not been tested to handle that much power.
The range of your signal depends on many factors. The height of the antenna has the most impact on range. The terrain and the power (Watts) of your transmitter also affects the range. Signal penetration is just as important as range and the power (Watts) of your transmitter affects penetration strength too. Basically the higher the antenna and stronger the transmitter the further you can go up to a point. Once you reach about 50 to 100 KM the signal cant go much further because of the curvature of the earth. In most cases though signals from about 10 Watts to a few hundred watts can make it about 30 to 50 KM. Very powerful signals of a few thousand watts and up can make it to about 100 KM.
Lol red flag!!! Lock him up he spelled a word wrong. Yeah this whole video must be a fake. There is no such thing as a dipole antenna if there is an incorrect spelling.
Thanks. No this has been chatted about a lot. If you scroll down the chat you will see mostly that although some people like using a balun it is not necessary. But I think this argument/discussion will never end lol.
This is an excellent and very detailed video. I appreciate the time and effort you put into it.
A few years ago I made a dipole by enclosing copper wire inside 1/2" PVC pipe. However, it was cut to one frequency so changing frequencies is not possible.
I used a washer on each end of the pipe, inserted a zip tie through the washer and secured it to the end of the copper wire so it would not collapse inside the PVC pipe. Next, I capped each end and sealed all holes and mating surfaces. I did not consider the VOP through PVC pipe because it was not necessary for my needs. I only wanted it to reach my garage, but during my first test, I found that it would reach 1.5 miles with a half a watt.
I really enjoy building my own antennas. I found that it is fairly easy to have a great antenna without spending a lot of money.
Funny that you should mention your homemade antenna with PVC pipes. I have been considering making a video about making the cheapest antenna ever using PVC etc. The tuning part is where I got stuck. I have tried many variations on it to make it tunable but not too much success yet. I have almost solved it but it's still in the making lol. I will post it as soon as I am happy with the design. The problem is that the kind of PVC that is useful can be almost as expensive as thin aluminum. If you do it right aluminum and spring steel like flexible antenna rods are cheaper and make the antenna tunable. Oh by the way, yes 0.5 of a watt is actually a huge amount of power. If high enough it can reach up to 7 miles. You need as little as 0.05 watts to reach your garage. Thanks for your comment. Always fun to chat about these things.
@@inspiresoundpro I prefer aluminum but PVC is very cheap and very easy to get where I live. The downside is not being able to tune for another frequency, the upside is I get to build another antenna! I have built several. Some are just for receiving and they work great. Unfortunately, many FM stations here are owned by just a few major corporations using very similar formats. Originality is nonexistent.
When I tested the range, it was with the antenna standing in a corner inside my house. I never mounted it. Actually, since it was far more capable than needed, I only used it one day out of the week while I was working outside.
I subscribed to your channel. I like the content and look forward to your next build.
Hey, thanks for the sub. I'm glad you like the videos. I am busy working on a quarter-wave design. It's a bit more difficult to build than the half-wave dipole but it's great for an omnidirectional signal. Dipoles are a bit directional. I will post it when it's ready. Cheers
Thank you mr.radio God for all that mumbo jumbo. Now put down your bongs it's time for class. If you have a licensed full power fm station you don't build a complex setup like described here in the previous comment. Fine if you just enjoy playing with wire but not a real world solution. Let's start with the dipole because I have some issues with that. There's a chart available free online for determining the length of the radials and I personally wouldn't use aluminum I would use copper. You shouldn't need more than 2 , 8 foot lengths of half inch copper pipe. Following the information on the chart for your frequency and power level carefully measure,( measure twice cut once) you will need a connector for 50 ohm coax and a 50 feet run of said coax and the connector should be female for attachment to the coax and the other end of the connector should be open so you can solder 2 , 6 inch pieces of number 12 stranded wire, one to the center conductor and one to the outer conductor. A simple round 4 pole pull box will be the center of the antenna. You will put one radial up and it goes to the center conductor and the other down going to the other conductor. To one side you cap off the port because it won't be used and the other remaining port you put a three quarter inch 90 pointing down and you put another 90 into it opposite of its direction.you then put a capped and trimmed slightly longer than your radial, three quarter inch PVC over the upper radial and an identical length pipe with a cap on the bottom but drill a small hole in the bottom cap so any water that may get in can drain. In the video a crossover plate was used to attach to the vertical pipe,( pole) but instead you use what's called a pipe to pipe bracket,( also available at home improvement stores) and that way you have several degrees of down tilt available to fit into your contour. This setup shouldn't cost more than $50 for everything except the coax from your transmitter to the antenna. To pre adjust the swr simply with transmitter on move the radials to and from each other until you get around 6 db. Once you've installed the antenna you can both alter your power and mechanical down tilt to avoid over modulation and exceeding your contour. For less than $250 including the transmitter you have an fm station that at one miliwatt should easily transmit 15 miles or more and as long as you keep your swr around 6 you shouldn't have wonky wave or distortion. Commercial stations don't build their own antennas they buy them from companies like Harris or dielectric or radio frequency systems. If you aren't getting the swr you need at power then you can add another identical antenna above or below and run them from the same transmission line but you will need a 50 ohm T connector and a jumper coax to supply the second element. Thus creating an array. The second element and connector shouldn't insert enough loss that you can't compensate for by adjusting power level. Keep it simple stupid. All those amplifiers and multiple lines coiled up, I've been doing this for 29 years and never have I seen anything like that. Not on commercial stations or lpfm. There's a million ways to do anything but why make it complicated and expensive?
@@dansteel9873 WTF are you talking about? Your reply is WAY out of context for this DIY project.
30 year plus veteran broadcast engineer here, let me see your breakdown of these antennas is quite good. This video actually serves two purposes one to explain in layman's terms what's going to happen. And also the technicians that get too deep into the engineering., I have seen some antenna Rays with as many as 16 circular polarized dipoles stock at one wavelength apart, taking up most of a 400 ft tower. All being fed using Ridgid cable. I've also made them with rg59 coat hangers and PVC pipe. The only limiting factor is rg59 can only withstand about 100 watts. In that case we would use rg11, which can handle approximately 500 to 1000 watts. Usually we design each dipole to handle 50% of the total power will be feeding into the system even if it's a four-way system, will still design them to take usually around 400 watts each. I've also seen systems, where you have four dipoles on the tower. The cables on them are all long enough to reach the ground. And then all of the same length. Each dipole is connected to the output of a separate power amplifier, the inputs to the power amplifier are generated by a divider Network after the exciter. Essentially the phase splitting and alignment, is done at the input of the amplifiers has the amplifiers do not add significant phase shift. This can't be said for all amplifiers. But in most cases the modern solid state ones can do this. It's actually possible to obtain 100,000 watts effective radiator power using only 10kw of amplifier. Each dipole, is built into 50 ohm antenna. All the cables are exactly the same length of 50 ohm coax. And yes this uses hundreds of feet of coax to do this. You must have the same length at the Top Antenna as at the bottom antenna then all the cables are ran back to the transmitter. Where you would have the output of 10 seperate power amplifiers. Each power amplifier feeds one antenna.. the input of each amplifier, comes from a power divider network. Essentially the same thing you're building for the antennas with coax, you build a smaller version that stays down with the amplifier. The beauty of the system is that it's easy to install you just roll up the excess coax and cable tie it to the tower. Once you have all the antennas spaced on the tower and everything is ready to go. With the multiplied gain of 10 dipole antennas, we're being effective radiated power of 100,000 watts. The true beauty in the system. Is that should you decide you want a small amount of beam tilt, either up or down it's going to be accomplished by just changing the length of the coax feeding the power amplifier to that antenna. And up or down beam till is easily added
Wow it's always great to hear about the big installations and to hear from broadcast industry professionals. So thanks for your input. I unfortunately never got work on such big set ups. It's even difficult to comprehend that kind of power and all the issues that go with it. In most of my set ups if it went wrong the transmitter would go into safe mode until you fix the problem with no real consequences but at your power levels it's a whole different ball game. The cost as well in a completely different league. I think the majority of my viewers will never encounter set ups like you have worked on so always interesting to get some input about it. Thanks for you nice compliment. I do try my best to make my videos as accurate as possible while making them as understandable for everyone as possible. The majority of my viewers are first timers so I try to make the information as accessible as possible. Thanks again for your input. Always appreciate getting feedback from professionals. Cheers :)
@inspiresoundpro just because the power levels go up, the system only gets more complex due to the size of the components used. However there are several of these antenna systems that are described using multiple amplifiers and multiple dipoles, sold by a company out of Latin america. It's actually a very ingenious system as you don't have to have crazy Tower mounted power dividers. They use basic diapers made of aluminum tubing with a plastic Center insulator. I believe they feed them with LMR 600. The number of feet per antenna Escapes Me Right now, but the system is somewhat built to order so that they can optimize the cable length however all cables are of equal length. And then it uses a stack of multiple 1 KW power amplifiers. Most modern FM transmitters even from the cheap ones sold on Amazon up to the biggest commercial units all have powerful back at SWR protection. As the broadcasting industry we have issues with our basis. It could be anything from a lightning strike, to birds deciding to building a nest on the feed point. And he has to be our becomes unstable. Or in one case there was a gasket missing on the feed line, and the entire feed line filled with water. I had drill 1/8 inch hole at the lowest point in the system and had water pouring out, also being pushed out by the nitrogen gas we use to pressurize the cable. However the nitrogen have been turned off for several weeks, during the winter time when we had heavy rain and storms. So the cables ended up filling up with water. The only difference in low-power to high power are physically the size of the components their power consumption when you plug them in, and the height of the tower you need to get the antennas away from human beings to not cause problems. Also your harmonic filters need to be very robust and have sharp cut off. So that you don't cause serious interference. Your basic Broadband low pass filter that cuts off at 110 MHz is woefully inadequate. I would highly suggest anyone attempting to build their own transmitter or Exciter board. Do some research into the design of these filters. The fixed capacitor values, could be reduced slightly and then parallel with a adjustable trimmer capacitor. Thereby allowing the operator to tune out and know the second and third harmonic. As the current FCC standard requires your third harmonic to be 60 DB lower than your main carrier, it is hard to achieve that using a Broadband filter circuit tuned for just below the aviation band. Normally I would have a 5 or 6 Pole low pass filter mounted in a small chassis box on the Exciter, then good coax between the chassis box filter and the input of the FM amplifier. In some cases should have been a particularly dirty radio system with a lot of harmonic issues we would add an interstage filter you clean up the output of the Exciter feeding into the intermediate power amplifier. We found out by doing this we actually gained about 10% more output power then before, as we were cleaning up the signal before it went into the main power amplifier and was not as wide, therefore the amplifiers gain was all focused on one frequency rather than a broadband signal along with noise. Similar to you how 1,000 Watts on FM radio goes a lot farther than a thousand Watts on television. Because if television signal is 6 MHZ wide, so when you refocus the wide band signal to a narrow band signal you gain efficiency at higher output levels
Great video ! Youre attention to detail and effort is remarkable. Your video is very enlightening thank you very much
You are very welcome. Thank you for the nice words :) Its always nice to be appreciated. Have an awesome day.
It is amazing how much work went into making this video. Amazing :D
Thanks so much. Yeah it was the most time I have put into a video so far so thanks for noticing and mentioning it. Really appreciate it :)
I appreciate the graphical detail and wish other could use it along with real pics of what is going on. This is what information sharing is all about. Making it understandable.
Thank you. Yeah I try my best. It is difficult though to create these kinds of graphics so are not as common. The only other way is to use things like CAD graphics which is very unlikely. But I hope its clear enough. Thanks. Cheers :)
and not to forget: the video is super!
Thank you I'm glad you enjoyed the video :)
What about a balun for this antenna , what will be the gain for this antenna ?
Thank you for the video , answering this questions will be helpful and good to improve the mach and performance for this antenna
Thanks for your questions. I have to laugh though because the balun question comes up every so often. It has been answered very well below in other comments but the short answer is no it does not need a balun especially if it's used only for transmitting. If you use it as a two way antenna or only for receiving then it might be useful but not necessary. The antenna has zero dB gain. Most quarter wave and half wave antennas have zero dB gain. If you stack them together in pairs or more you can Increase the gain. Check out my video on antenna arrays for that. This antenna is designed to be tuned so that is where the real benefit is . Cheers.
Thank you! I will be using this antenna to simply receive FM signals. How would I adjust the aluminum rods to tune it to a specific frequency? The video you recommend at the end titled, ‘FM Transmitter How To Build Circuit DIY Homemade’ does not explain how to tune (adjust the aluminum rods) on this adjustable Dipole antenna for maximum receiving of FM signals. Maybe I missed something. Thank you again. I like the way you explain the build process. Very clear and thorough!
You are very welcome :) Yes I have a video on how to tune antennas. My channel is mostly focused on transmitting but the same principles apply for receiving. Only problem is that to tune the antenna perfectly you actually need to run a transmitter into in to measure the return signal or you have to buy a fairly expensive antenna analyzer. The best option for receiver antenna is to simply adjust the antenna by physical length to as close to the signal wavelength as possible. The video to watch is this one : th-cam.com/video/WOGX70-kIYA/w-d-xo.html
It is intended for transmitters so most of the tuning wont apply but it does explain how to calculate the antenna length using an online calculator.
Can I use this adjustable dipole antenna for simply receiving FM signals? All I want to do is receive a strong and clear FM signal on my FM receiver. In other words, is this adjustable Dipole antenna project ‘overkill’ for simply receiving FM signals or would I be better off simply building a fixed length basic dipole antenna? Thank you kindly for this DIY adjustable Dipole antenna project. Looks fantastic!
Thank you. I always enjoy it when people get some value form my videos :) Yes this antenna can work very well for receiving. It may be an overkill if you only want a slight improvement but if you are far from a transmitter like in rural areas then this antenna is great for that. You can also build a directional version but that would be way bigger and difficult to install. For transmitting and receiving this antenna, especially if you tune it to the frequency you want, will give a very strong signal.
@@inspiresoundpro Thank you. I am going to ask a different question and didn’t want to bury it here. This way others can see it more easily and learn from your answer. Thank you!
@@youtubecommentor4480 the sizes and sturdiness are overkill for listening to broadcast fm. I made a simple dipole of 1/8" solid copper wire and mounted it horizontally (broadcast fm is circular polarized) and it has exceeded expectations. Amazon sells small diameter nesting aluminum and copper tubes that would be great too. if you take a look at commercial outdoor antennas, they use 3/8" diameter elements or even smaller
i might have another question: why is the wood dowl only 5 cm long. For strenght it might be better of with 10 cm?
You can make the wooden dowl stick longer but it will not change the strength because the strength comes from the bolts holding the aluminum rods to the box.
Make a bulan coils using the coaxial cable, just roll a few turns Wil be ok, it's to unbalance to balance the coaxial and the dipole 👽👍📡 📻
There are two opposing opinions about baluns for dipoles. For receiving antennas it can make a difference with reducing interference so if you use the dipole to receive or as a two way communication antenna then yes it can be useful but if it is purely for transmitting like this dipole was designed for then you don't really need one. I have run very low power and a few hundred watts with no balun and had great signals. The antenna tuning was more important. In many cases a balun, especially the wrong type of balun can hurt the signal more than help it. So there are differing opinions but for transmitters I have found it best not to use one.
4...6..tur balun😊
hello, have the instructions already been out? is there a need the bolts are 10mm x 50 mm and 6mm in diameter? which material are they made of?
The idea behind the design is that it can be adapted to the parts available to you. A range of box, bolt and aluminum tubes can be used. The dimensions given are the ones that work well together but the dimensions can be adapted to your size box and aluminum rods. Some people have even adapted the design to other frequency bands like Vhf and uhf. The idea is not for it to be a one size only design but rather a template to adapt to what you have available. The wavelength for FM band though means keeping the lengths of the rods the same but most other things can change.
Un grand Mercie .
Je vous en prie. Je suis heureux que vous ayez apprécié la vidéo. Merci beaucoup :)
You are welcome. I'm glad you enjoyed the video. Thanks so much :)
I am really enjoying your videos.
I dont know if its your wording or specifically how you explain things but your videos are very intuitive.
Thanks for the content.
Thank you so much. It's really awesome to get your feedback. It can sometimes takes weeks to make videos and when I release them I don't know if I did it right LOL. Some succeed some don't. I guess I'm always learning. Even though I have experience in broadcasting and video I am quite new to TH-cam so there is always something new to learn. I try to make videos the way I would want to watch them so I try to solve problems the way I would need them solved for me so I think that's what makes it seem intuitive. Thanks so much for your feedback. It helps to keep going. Cheers :)
@@inspiresoundpro im sure your experience is a major player then. Knowing what is useful and relevant.
I feel like no matter the field, even with professionals they often fall back to cookie cutter recipes and give no thought to the reason or know little about the nuances of what makes it work. Thats great of we bake the same cake in the same kitchen. But for the rest of us in our own kitchen, it is amazing to have teachers to teach us why the oven temperature is set the way it is.
Agreed. That's why I don't even try to do things other channels are doing. I think of what I would like to see and then I try figure out how it should be best explained. I find that if I am doing it correctly that I end up learning new things too as I go along because I need to be able to re-create the solution myself. If I just do generic solutions it's often not really of any help to anyone.
Excellent video, but! You forget ballun. It is very important to have ballun between cable and dipole!
Hi. Thanks for your comment. Yes its true that it is commonly believed that a ballun is needed but in fact there are many engineers who believe that a balun is most likely to be done incorrectly and therefore would do more harm than good which is most likely when first time builders use one. The ballun can reduce some interference and match impedance but if the antenna is built correctly, tuned close to resonance, and installed correctly the ballan will most likely make no measurable difference to the transmitted signal. In two radio where the antenna is being used for transmitting and receiving then a ballun can be more noticeable but for a purely transmitting antenna which is what this design was intended for, a ballun is not really needed. I do appreciate your input though. Its always great to chat with people about this because it gives newcomers more insight into things they might not have heard of. And to add to this I ran a low power commercial radio station with a 1 Watt Fm transmitter and we did not use a ballun and the signal was fantastic. The reason is that the antenna was high up on a hill and tuned and installed very well. These things matter way more than a ballun. This is something I try to get my viewers to pay attention to more as it will dramatically affect their range. Thanks so much. Cheers.,
What is common to use a balance on HF frequencies, and VHF frequencies is not necessary, the dipole itself when Tim correctly should be almost a 50mm resistive load. So feeding it with a length of 50 ohm is perfectly acceptable. The phasing coax or power divider coax, it's usually made from 75 ohm, either rg11, or RG6 with Copper sheld, the point where the two interconnect, can be as simple as a basic coaxial t connector. Important part is to make sure that all of the coaxes are the same length. If one cable is even a few inches longer. It will cause the signals to not be in Phase when they leave the tower. You also have a high reflected power on your meter.
Thank you .Always great hear from people in the field. Yes as you said the idea of a ballun for all uses is not correct. In many cases the use of the ballun distracts people from paying attention to what you mentioned which can make a much bigger difference. Also I think some people think that the ballun fixes all problems which is not a good way to think. Thanks so much for your input. My viewers do seem to learn as much from the comments as the videos. Cheers :)
@allen_steel1236 ballun using not only to transform resistance. It is used as a bridge from an unbalanced coaxial cable and balanced dipole. If you connect them directly, there will be some standing waves on the body of the transmitter, and depending on how much power it can cause damage or errors on devices, connected to transmitter.
@@katushechnik Thank you. It's always great to add this kind of insight. It's the kind of thing new viewers enjoy seeing. Cheers.
plz make on circular/cross polarized antenna also
I will work on it. Circular is much more complicated so it won't be soon but I will add it to my list to work on. Thanks so much :)
dear sir
i need 2 type of aluminium 1st is aluminum pipe and 2nd name is ?
and waht is aluminum pipe diameter ?
i have 300watt am amplifier
ple reply
Hi. The pipes are all aluminium. Aluminum is just the way Americans say aluminium. It's the same thing. The measurements for the pipes are all in the video. Check out the beginning where all the measurements are listed. 300 Watts might be too much power for this antenna. It has not been tested to handle that much power.
@@inspiresoundpro thanks a lot sir
Km Range?
The range of your signal depends on many factors. The height of the antenna has the most impact on range. The terrain and the power (Watts) of your transmitter also affects the range. Signal penetration is just as important as range and the power (Watts) of your transmitter affects penetration strength too. Basically the higher the antenna and stronger the transmitter the further you can go up to a point. Once you reach about 50 to 100 KM the signal cant go much further because of the curvature of the earth. In most cases though signals from about 10 Watts to a few hundred watts can make it about 30 to 50 KM. Very powerful signals of a few thousand watts and up can make it to about 100 KM.
@@inspiresoundpro Okay, thanks Bro ❤️
0:20 "dimensions" is misspelled. red flag! oy, here we go...
Lol red flag!!! Lock him up he spelled a word wrong. Yeah this whole video must be a fake. There is no such thing as a dipole antenna if there is an incorrect spelling.
Balun?
Thanks. No this has been chatted about a lot. If you scroll down the chat you will see mostly that although some people like using a balun it is not necessary. But I think this argument/discussion will never end lol.
Hi can someone please email me this blueprints of this video please