Rubbish. Anyone with real world experience will tell you the 5/8 definitely does smash the half wave, its all good on paper but actually the half wave is WAY noisier and is deaf compared to a 5/8. iv tried both at varying heights and will never touch a half wave again. ever.
A real world test would be interesting indeed. I changed from a 1/2 wave to a 5/8 wave antenna (both vertical, at 6m height, but different brands ) and the 5/8 performs really a lot better, as well for DX as local contacts.
Great work TIM, interesting comparison of the two antennas. The 5/8 is better at ground level but the 1/2 wave at 3m will match it right. Great for field radio SOTA or POTA. 73 👍🏽👋🏼
Thinking about going back to the roots and maybe putting a classic CB Ringo-Ranger for 10m on the roof. Not sure what the neighbors solar panels / inverter will do to it, but it was working very well in the last solar cycle.
@@timg5tm941 This mah be a coincidence, but I have found the the power supply may have a lot to do with QRM and QRN. I installed a new station for a rural ambulance service. I left my cheap power supply for their base station. It powered the station just fine and was okay when it came to noise level. When their expensive power supply came in, I switched out the power supplies and their power supply seemed to allow the station to pick up a lot more QRM and QRN. I could hear distant lightning when the sky got cloudy. With the cheap power supply, the storm had to be on top of the station to hear the lightning. The squelch had to be turned up and RF gain down because the QRM was quite bothersome. The engines of the ambulances made a lot of spark noise when they came into the garage. With the cheap power supply, it was barely a his when they came in. Granted, the new power supply may have been defective. But it powered the station just fine and gave no 60hz hum. I did notice that the cheap power supply has an aluminium housing and the expensive one has a plastic case. If I had extra money, I would buy the expensive power supply and do some experiments. Something is acting like an antenna in the expensive power supply.
Hey Tim -- Thanks for a solid video, as always. One idea for a future video, where content seems to be lacking on UA-cam overall, is related to verticals that take advantage of a cap/capacity/capacitance hat, as an alternative to linear loading and/or adding an inductance coil to effectively shorten the antenna. I don't know too much about it, but from what I've read, if you can get the capacity hat (top hat) on the end of the antenna, it may be preferable to the other means of shortening? ... What I think would be interesting is to understand if the value of adding a capacity hat for a 10m to 20m halfwave vertical would allow you to raise your shortened antenna higher enough (on say, a 12m Spiderbeam pole) to get additional gain at low angles for DX. Maybe for 10m those ~2 additional meters (guessing here) in height might have an impact? Seems like it's perhaps not as big of a deal on 20m. Either way, that capacity hat method of shortening could be a good content idea for you, if it interested you. ..... I do have one other question that has arisen in my mind, which you might know the answer to: when using a half-wave vertical (e.g., T2LT design) for 20m, and if you ran an ATU to get it working on the lower bands (17, 15, 10m--which I guess Callum was able to do on his a few years ago), would the efficiency drop out for those lower bands (not because of the tuner losses, but rather because the antenna no longer represents a half-wave at those frequencies, and as such the need for a more elaborate radial and/or tuned-counterpoise system would arise to combat ground losses)? Or would the fact that it's a half wave on its true resonant frequency mean that there are really no radials necessary when operating at lower bands through an ATU? I suspect you might know, but no worries if not! 73 and all the best.
Thanks Tim! FYI Hy-Gain has a "5/8" wave monoband vertical antenna (with radials) for 12 or 10 meters (SPT-500) that is actually a 5/8 element with short linear loading at its base bringing it up to 3/4 wave electrically. This design should do a bit better than 1/2 wave antennas as it has another high current point at its base. The LL is 3 wire design to bring the feed point to the bottom of the antenna where its radials stick out. Just another design you might want to consider tinkering with. 73 mike
Interesting comparison to the halfwave, I wonder in the real world what the impedance difference is between the two at the feed point. I’ve had the thought of building a 5/8 wave on the beach but just never did it. Great video Tim!
Hi Walt. Feedpoint swr seems to be around 40:1 for the 5/8. I’ve read that a small coil at the base around 2.5uH can bring the antenna into match by fooling the radio that you have a 3/4 wave and hence a better match to 50 ohms. An impedance stub does a similar thing. See Mike’s video in the details section . Take care friend 73.
Thank you so much sir for this very informative video. You see, I am just new to HF and starting with 10 meters because a very good friend of mine gave me his HR2510 to start with and since the 10 meter band is open for a few more years to come, I would like to take advantage of the situation to make some contacts. In fact, if I may share, I've made my very first contact to Germany which is more than 10,000kilometers from where I'm at with just 12 watts and an aluminum dipole 19 feet above the ground. Boy, was I so thrilled about the experiencd. So now, I am trying to explore different antennas I can build. Again, thank you and all the best. 73s...
I am having good results on my Sirio 1/2 wave tuned for 10m when compared to my Endfed halfwave mounted at the same height as the bottom of the vertical. Thought about a 5/8 but with the extra metal in the air creating a potential faliure sooner than the 1/2 wave + Tim's checks on this video, seems like I am best sticking to what I have. I can use the antenna on 12m and 20m as well just using the FTDX-10's internal tuner. 73 from Mike M0SAZ
Hi Tim, thanks for the video, interesting. If 10m was open at your beach location, Would you agree a simple vertical on the car or a 1/4 wave on the ground, would probably work just as well, considering the very slight difference in the 2 for mentioned ants, and thetefore eliminating
Good work Tim. I've just replaced a 24ft IMAX 2000 with an Opek fibreglass halfwave. Far more rigid! I live by the sea, so I'd rather have more scaffold pole and less antenna.
@@timg5tm941 2 weeks in and the Opek is performing absolutely brilliantly - just as the modelling predicts, when mounted at height. Far less bendy than the IMAX too!
Tnx for the video, interesting one 😀 A 1/4 vertical with tip on a 12m pole will give the same gain at 5deg and similar pattern as the 5/8 or 1/2. The disadvantage with 1/4 and 5/8 is they will need 3 or 4 radials to work. So for portable quick instalation on a limited space the 1/2 is a great choice. If space around the pole available the 1/4 is great since easy to build and the 4 radials extended by rope can be used to guy the pole. If you go to a windy spot which usually on the shore line is sometimes you have to guy it anyway 😁 The 5/8 gets complex if on the top of the pole. Will need some radials as the 1/4 and extra matching circuit which can be heavy and bulky to install 5m up on the pole... 73 de Andrej - s57rw
Nice video again Tim! You're answering the questions all of us like to be answered :-) What I am struggling about is if I could use that 10 meter 1/2 wave also for 20 meters, with the use of a good tuner. Do you have experience with that?
Hmmm not really but you could with say 2 elevated 1/4 wave radials. Then you’d have a 20m ground plane antenna. You’d need to feed that with a 1:1 current Balun though. It’s a different antenna (though very very similar in size vertically) to the 10m 1/2 wave
@@timg5tm941 Thanks for the tips! I allready tried to simulate it in mmana by just changing the frequency of the 10 meter version to 14.200 Mhz. The result leads to strange ineffective lobes...
Thanks for the comparison. There is another factor for those of us who are height-challenged. Due to an HOA, a half-wave will fit in my attic while a 5/8 wave will not.
I know at times there is no option when you are picking a home to avoid HOA areas. But, I have turned down great houses, at very good prices, to avoid an HOA. I just do not want more government in my life. There is already too much of it in all our lives.
Hi Tim, I really appreciate the video, my new property came with a Sirio GP27 1/2 wave at 118' atop a Sugar Pine and I have been arguing with myself as to whether or not I should pay $800 for a 5/8 Colossal and the climber just to get a sliver of a dB more?!? LoL not after viewing this video! I am curious what mic you're using, it sounds what we studio mic guys call "Juicy!" - and that's a good thing! 👍🤓 Thank you & 73
The 5/8 was considered better for local (ground wave) contacts , A 1/2 wave was considered better for DX. I always thought that was nonsense and you just proved it.
I use a half wave dipole on 10 meters, about half wavelength high. It's not perfectly vertical, kind of a slight sideways V shape in a tree. It has swr of 1.3:1 or better, no balun. I've been able to work all continents so far.
Ah, a fellow vertical dipole believer. I have set up several of these ugly, simplistic, primitive, antennas. The people I have set them up for have had absolutely no complaints at all. If I were an amateur radio operator, I would set a vertical dipole because of the simple, yet proven, performance. Perhaps I may set up an antique CB radio station. However, I think that band is not used much any more.
good science.. i guess the half wave catches the 5/8 because the antenna is higher off the ground, when the tops are level.. have you done some testing of a vertical half wave vs a vertical dipole, id love to see the differences with height..
Hi Steve theres no difference between the radiation patterns or gain as long as both 1/2 waves are the same height above ground. Higher though is better!
That’s matching my experience. I made nice DX with an efhw, fed about 4 meters over ground, my QTH was about 600m above sea level. Free sight all around. Worked Indonesia with 20W. I don’t think a 5/8 Lambda antenna would do much better.
I think an issue with the 5/8 is that with 1/4-wave radials, the currents, in the radials, are out of phase with the main current in the vertical radiator?
Surely the lack of ground plane/counterpoise or distance from it will have major impact. My portable vertical I run at least a couple of counterpoise , even if I am in a layby.
Nope .. the 1/2 wave T2lt design does not require any ground plane. Nor does the excellent 5/8 wave Sirio Gainmaster. In fact the main differences between them are: 1. Their length; 2. The use of a short impedance matching stub in the Gainmaster which helps to fool the radio that the antenna is a 3/4 not a 5/8 wave. No ground plane needed.. unlike the 1/4 wave.
I assume 1/2 wave is an EFHQ feed at the bottom thru a 49:1 unun. Am I correct? What type of unun would you recommend for the 5/8 wave antenna? I believe we need to use some radials or counterpoise. Am I correct? What lengths would you recommend for that?
The end fed could be fed with A 49:1, a tuned LC circuit match or make a flower-pot style half-wave using a narrow band choke out of rg58. Any would suffice, although the latter would need to a metre or so above ground. For the 5/8 I would recommend checking the design for the matching unit. Search MM0OPX's channel - Colin has made such an antenna.
what gets me is the rabid tribalism of the two parties espousing that one is significantly better/different than the other whereas as Tim points out there isn't actually that much of a difference. There also isn't a hard & fast limit on the exact 5/8th. Rather than looking at "quantized" 1/2 wave & 5/8th it is worth looking at a continual smooth migration even from quarter wave (=2/8th =4/16ths) up through 7/16th, 8/16th (half wave), 9/16th, 10/16th (5/8th) & even 11/16th. The starting quarter wave is pretty "rounded" with a fair amount of equal high & low angle (just nothing straight up). As you go up from 1/4 wave the high angle radiation drops down & concentrates into the low angle lobe as it moves out. There is no "switch point" between lengths as there is a smooth transition... HOWEVER.. when you start going past 5/8th the low angle "horizon" lobe starts to reduce again as a high angle "spur" then starts to grow (taking this to the extreme at full wave vertical you get the high angle "X or V" pattern). One of the reasons that the 5/8th was historically preferred over the half wave was that traditionally the very hi-Z 1/2 wave can be a bitch to feed (decent big ferrites previously more difficult to obtain) & the 5/8th was much easier to feed..... I've still got my 1970's 145MHz Revco 5/8ths mobile whip what was the first "gold standard" improvement over the original quarter wave whip... oh how things have moved on since then via 7/8th & now dual banders. The other thing to watch is all these computer modelling tools "perfection" is not 100% matching the horrible real world ground conductivity variation, real counterpoise/radial variation, adjacent metalwork interaction etc etc hence I can totally understand that someone may have had a bad practical experience with one variant but when they tried the other it worked better hence the "this works/that doesn't" tribalism. Others can have completely the opposite experience depending on their specific circumstances but neither is right or wrong for everybody. "computer says YES, but your particular reality may say NO". If we however don't go much past "5/8th on highest band of interest" (to avoid the high angle spurs starting to appear,) & then think of it multiband ... from Tim's calculations you are talking about just over 20 feet for 10m 5/8th (but as we have said even a smidge longer isn't a "showstopper" so 25' isn't outside the realms of the practical), then together with this radiator you need a matcher..... hey depending on what exact type of match you use you have just defined the comet vertical with its heat sink finned baked bean can feed on the base, or with a slightly different feed you have just defined the rybakov antenna or if you "double it up" for a balanced antenna you have just described the half size 5RV..... all they have done is pick a length around 20 to 25' to try and avoid a perfect 1/2 wave on any amateur band because of the difficulty in having their particular wideband matching from hitting that particular difficult high-Z. You want another laugh... look at the feeding a half wave with the 49:1 vs 64:1 tribal debate... with very few mentioning that with a 2 turn primary you can have 14 or 15 or 16 secondary turns hence 49 or 56 or 64:1 (& if you have a 3 turn primary you have even more variability). Your wire thickness, ground conductivity variation, short counterpoise tail length, conductor diameter, exact length & adjacent metalwork will all influence which ratio YOU need.... there is no one universal answer to 64 or 49:1 for everybody. Tribalism is pointless.
Hi Tim , I have used both on ten .i didn’t notice much difference 5/8 seemed to have the edge on receive, but this could have been the greater overall higher.i am currently using a 5/8 mounted above a 5 element Yagi . Question would the yagi act as a ground plane,and if so how would this effect the take off angle?
Fun fact: All verticals are dipoles, but not all dipoles are verticals. At first one will think, my fun fact is incorrect, even laughably stupid. However, considering that a quarter wavelength vertical must have a ground plane for it to function correctly, the second half of the dipole is the antenna ground plane which makes for an unbalanced dipole. As for not every dipole is a vertical, that is self explanatory.
every ant on every band will behave differently in every location and times of the day, but if 10m is open , a wet piece of string would probably work anyway. the smallest ant is always easier to set up for me, and the smallest amount of power required to get a qso, is all thats needed. so many folk seem to complicate simple things.
Hi Andy for short hops around 500 miles or so then any height from 8 to about 40 feet would be ok. It isn’t until you get about 50 feet or higher (3/8 wave) that a dipole improves markedly for DX. My dipole is an inverted V.. 25 feet at apex and 7 feet off ground at the ends. Does well for inter G. 73
@Tim G5TM thanks Tim just watched an older video of yours explaining this:) do you get more noise the lower down it is or no difference? Thanks so much
I've used both and i.ll be honest work pretty much the same on 10 meters same height and same power slight difference is the 5/8 has a ground plane unlike the half wave. Question what difference does the ground plane make on my 5/8 wave .
If you model a 1/4 wave with a few elevated radials on a 12m pole you might be surprised at the pattern. It's nearly identical. Given that a 5/8 really only has 1.5db gain over a 1/2 wave (and that's when compared over perfect ground etc.) The 1/2 is the obvious choice. I've rebuilt my T2LT to your design specs and mounted it with the break in coax an exact electrical 1/2 wave above the ground and it's a DX machine. Just shy of 60 DXCC's worked in north/south America, Europe, Africa and Asia on 10. SSB, AM and FM with 5w and under so far this year.
Good question. With the three antennas FED at the same height the 5/8 beats 1/2 that beats the 1/4. So, indeed if we put the quarter wave fed at 9.5m I SUSPECT (I’m not by my pc now to model this), that it may well be close to or actually beat the other two. However, unlike the 1/2 and 5/8 you’ll need at least 2 raised radials at 180 degrees to each other for an omni directional pattern. A bit more of a hassle.
@@timg5tm941 More hassle indeed. But if it was better, it would demonstrate than antenna height gain is more important than antenna gain if you had to pick one. If it was the same, or worse, that would be equally valid and prove more wire was better than more height.
Likely inferior and laughably simplistic, but I have set up vertical dipoles for 10 meter band usage. The local forestry operates in ten frequencies from 27.750Mhz. I have also set up simplistic 10 meter vertical dipoles for home operators that use it from the 11 meter citizen's band through the entire 10 meter amateur band with marginal use on 12 meters with a small manual tuner. Primitive, ugly, simplistic, rather ungainly, but there are those that want me to set them up for them. Of course, a 10 meter vertical dipole will not work for mobile installation.
you can check how the same antena works at 25m over ground. i have one 10m delta loop at that hight. i have also one sky loop 160m and one ganmaster. 73 de sa6bzz
Rubbish. Anyone with real world experience will tell you the 5/8 definitely does smash the half wave, its all good on paper but actually the half wave is WAY noisier and is deaf compared to a 5/8. iv tried both at varying heights and will never touch a half wave again. ever.
Respectfully, that’s a load of bollocks. I think you needed to sort out your installation
@@timg5tm941 iv done plenty of installs over the years, its my job, and a half wave is junk compared to a 5/8. cant argue with real world facts
it might be 6 months later....but youre wrong! a 1/2 wave is just as good!
You guys should fist fight about it.
A real world test would be interesting indeed. I changed from a 1/2 wave to a 5/8 wave antenna (both vertical, at 6m height, but different brands ) and the 5/8 performs really a lot better, as well for DX as local contacts.
Great work TIM, interesting comparison of the two antennas. The 5/8 is better at ground level but the 1/2 wave at 3m will match it right. Great for field radio SOTA or POTA. 73 👍🏽👋🏼
Thanks Ferdinand! 73
Thinking about going back to the roots and maybe putting a classic CB Ringo-Ranger for 10m on the roof. Not sure what the neighbors solar panels / inverter will do to it, but it was working very well in the last solar cycle.
That is okay, you both will get noise from each other. The first one to get nasty about it, loses. May the best technician win.
I have 3 close neighbours with solar panels and electric car chargers and have zero additional QRM
@@timg5tm941 This mah be a coincidence, but I have found the the power supply may have a lot to do with QRM and QRN. I installed a new station for a rural ambulance service. I left my cheap power supply for their base station. It powered the station just fine and was okay when it came to noise level. When their expensive power supply came in, I switched out the power supplies and their power supply seemed to allow the station to pick up a lot more QRM and QRN. I could hear distant lightning when the sky got cloudy. With the cheap power supply, the storm had to be on top of the station to hear the lightning. The squelch had to be turned up and RF gain down because the QRM was quite bothersome. The engines of the ambulances made a lot of spark noise when they came into the garage. With the cheap power supply, it was barely a his when they came in. Granted, the new power supply may have been defective. But it powered the station just fine and gave no 60hz hum. I did notice that the cheap power supply has an aluminium housing and the expensive one has a plastic case. If I had extra money, I would buy the expensive power supply and do some experiments. Something is acting like an antenna in the expensive power supply.
Hey Tim -- Thanks for a solid video, as always. One idea for a future video, where content seems to be lacking on UA-cam overall, is related to verticals that take advantage of a cap/capacity/capacitance hat, as an alternative to linear loading and/or adding an inductance coil to effectively shorten the antenna. I don't know too much about it, but from what I've read, if you can get the capacity hat (top hat) on the end of the antenna, it may be preferable to the other means of shortening? ... What I think would be interesting is to understand if the value of adding a capacity hat for a 10m to 20m halfwave vertical would allow you to raise your shortened antenna higher enough (on say, a 12m Spiderbeam pole) to get additional gain at low angles for DX. Maybe for 10m those ~2 additional meters (guessing here) in height might have an impact? Seems like it's perhaps not as big of a deal on 20m. Either way, that capacity hat method of shortening could be a good content idea for you, if it interested you. ..... I do have one other question that has arisen in my mind, which you might know the answer to: when using a half-wave vertical (e.g., T2LT design) for 20m, and if you ran an ATU to get it working on the lower bands (17, 15, 10m--which I guess Callum was able to do on his a few years ago), would the efficiency drop out for those lower bands (not because of the tuner losses, but rather because the antenna no longer represents a half-wave at those frequencies, and as such the need for a more elaborate radial and/or tuned-counterpoise system would arise to combat ground losses)? Or would the fact that it's a half wave on its true resonant frequency mean that there are really no radials necessary when operating at lower bands through an ATU? I suspect you might know, but no worries if not! 73 and all the best.
I’ll check these 👍
Thanks Tim!
FYI Hy-Gain has a "5/8" wave monoband vertical antenna (with radials) for 12 or 10 meters (SPT-500) that is actually a 5/8 element with short linear loading at its base bringing it up to 3/4 wave electrically. This design should do a bit better than 1/2 wave antennas as it has another high current point at its base. The LL is 3 wire design to bring the feed point to the bottom of the antenna where its radials stick out. Just another design you might want to consider tinkering with.
73 mike
Nice observations Mike thank you
Interesting comparison to the halfwave, I wonder in the real world what the impedance difference is between the two at the feed point. I’ve had the thought of building a 5/8 wave on the beach but just never did it. Great video Tim!
Hi Walt. Feedpoint swr seems to be around 40:1 for the 5/8. I’ve read that a small coil at the base around 2.5uH can bring the antenna into match by fooling the radio that you have a 3/4 wave and hence a better match to 50 ohms. An impedance stub does a similar thing. See Mike’s video in the details section . Take care friend 73.
@@timg5tm941 thanks Tim!
Thank you so much sir for this very informative video. You see, I am just new to HF and starting with 10 meters because a very good friend of mine gave me his HR2510 to start with and since the 10 meter band is open for a few more years to come, I would like to take advantage of the situation to make some contacts. In fact, if I may share, I've made my very first contact to Germany which is more than 10,000kilometers from where I'm at with just 12 watts and an aluminum dipole 19 feet above the ground. Boy, was I so thrilled about the experiencd. So now, I am trying to explore different antennas I can build. Again, thank you and all the best. 73s...
Great stuff! I hope you enjoy!
I am having good results on my Sirio 1/2 wave tuned for 10m when compared to my Endfed halfwave mounted at the same height as the bottom of the vertical. Thought about a 5/8 but with the extra metal in the air creating a potential faliure sooner than the 1/2 wave + Tim's checks on this video, seems like I am best sticking to what I have. I can use the antenna on 12m and 20m as well just using the FTDX-10's internal tuner. 73 from Mike M0SAZ
Does the job!
Hi Tim, thanks for the video, interesting. If 10m was open at your beach location,
Would you agree a simple vertical on the car or a 1/4 wave on the ground, would probably work just as well, considering the very slight difference in the 2 for mentioned ants, and thetefore eliminating
Interesting!!TNX Tim.
My pleasure!
Good work Tim. I've just replaced a 24ft IMAX 2000 with an Opek fibreglass halfwave. Far more rigid! I live by the sea, so I'd rather have more scaffold pole and less antenna.
Ah yes that’s pretty wise
@@timg5tm941 2 weeks in and the Opek is performing absolutely brilliantly - just as the modelling predicts, when mounted at height. Far less bendy than the IMAX too!
Tnx for the video, interesting one 😀
A 1/4 vertical with tip on a 12m pole will give the same gain at 5deg and similar pattern as the 5/8 or 1/2. The disadvantage with 1/4 and 5/8 is they will need 3 or 4 radials to work. So for portable quick instalation on a limited space the 1/2 is a great choice. If space around the pole available the 1/4 is great since easy to build and the 4 radials extended by rope can be used to guy the pole. If you go to a windy spot which usually on the shore line is sometimes you have to guy it anyway 😁 The 5/8 gets complex if on the top of the pole. Will need some radials as the 1/4 and extra matching circuit which can be heavy and bulky to install 5m up on the pole...
73 de Andrej - s57rw
Great points Andrej thank you 73
Nice video again Tim! You're answering the questions all of us like to be answered :-) What I am struggling about is if I could use that 10 meter 1/2 wave also for 20 meters, with the use of a good tuner. Do you have experience with that?
Hmmm not really but you could with say 2 elevated 1/4 wave radials. Then you’d have a 20m ground plane antenna. You’d need to feed that with a 1:1 current Balun though. It’s a different antenna (though very very similar in size vertically) to the 10m 1/2 wave
@@timg5tm941 Thanks for the tips! I allready tried to simulate it in mmana by just changing the frequency of the 10 meter version to 14.200 Mhz. The result leads to strange ineffective lobes...
Thanks for the comparison. There is another factor for those of us who are height-challenged. Due to an HOA, a half-wave will fit in my attic while a 5/8 wave will not.
Indeed a useful reason
I know at times there is no option when you are picking a home to avoid HOA areas. But, I have turned down great houses, at very good prices, to avoid an HOA. I just do not want more government in my life. There is already too much of it in all our lives.
great as usual Tim. many thanks.
Cheers Brian 73
Great work Tim.. I need to get on 10m I have a hawkins 5/8 I think. Never used it.
Motters M7TRS 73 👍🏻
It’ll work well .. 10 is beginning to blossom more and more
Hi Tim, I really appreciate the video, my new property came with a Sirio GP27 1/2 wave at 118' atop a Sugar Pine and I have been arguing with myself as to whether or not I should pay $800 for a 5/8 Colossal and the climber just to get a sliver of a dB more?!? LoL not after viewing this video!
I am curious what mic you're using, it sounds what we studio mic guys call "Juicy!" - and that's a good thing! 👍🤓
Thank you & 73
Hi Brann, its a Hyperex Quadcast - about 150 dollars, USB pluig and play mic. 73
The 5/8 was considered better for local (ground wave) contacts , A 1/2 wave was considered better for DX. I always thought that was nonsense and you just proved it.
I’m glad!
That's because users didn't factor in height and ground reflection if antenna too close to ground.
Very interesting results. I was not expecting that. Did you end up trying this theory in practice Tim?
Not yet but on the list
I use a J pole built for 10m , which is a 1/2 wave and i have worked as far as Japan with 100 watts from here in the Caribbean .... de 9Z4BM
Great stuff!
I use a half wave dipole on 10 meters, about half wavelength high. It's not perfectly vertical, kind of a slight sideways V shape in a tree. It has swr of 1.3:1 or better, no balun. I've been able to work all continents so far.
Ah, a fellow vertical dipole believer. I have set up several of these ugly, simplistic, primitive, antennas. The people I have set them up for have had absolutely no complaints at all. If I were an amateur radio operator, I would set a vertical dipole because of the simple, yet proven, performance. Perhaps I may set up an antique CB radio station. However, I think that band is not used much any more.
Brilliant!
good science.. i guess the half wave catches the 5/8 because the antenna is higher off the ground, when the tops are level.. have you done some testing of a vertical half wave vs a vertical dipole, id love to see the differences with height..
Hi Steve theres no difference between the radiation patterns or gain as long as both 1/2 waves are the same height above ground. Higher though is better!
Hi there, thanks for this perspective on the two options.
Question for you. Can you elaborate the behavior of these two in the near field (
Very interesting observations, thank you
That’s matching my experience. I made nice DX with an efhw, fed about 4 meters over ground, my QTH was about 600m above sea level. Free sight all around. Worked Indonesia with 20W. I don’t think a 5/8 Lambda antenna would do much better.
I agree
I think an issue with the 5/8 is that with 1/4-wave radials, the currents, in the radials, are out of phase with the main current in the vertical radiator?
Surely the lack of ground plane/counterpoise or distance from it will have major impact. My portable vertical I run at least a couple of counterpoise , even if I am in a layby.
Nope .. the 1/2 wave T2lt design does not require any ground plane. Nor does the excellent 5/8 wave Sirio Gainmaster. In fact the main differences between them are: 1. Their length; 2. The use of a short impedance matching stub in the Gainmaster which helps to fool the radio that the antenna is a 3/4 not a 5/8 wave. No ground plane needed.. unlike the 1/4 wave.
I have a Sirio GPE 27 tunable 5/8 wave that runs rings around the Antron 1/2 wave in the identical same spot with the same coax and everything
I assume 1/2 wave is an EFHQ feed at the bottom thru a 49:1 unun. Am I correct? What type of unun would you recommend for the 5/8 wave antenna? I believe we need to use some radials or counterpoise. Am I correct? What lengths would you recommend for that?
The end fed could be fed with A 49:1, a tuned LC circuit match or make a flower-pot style half-wave using a narrow band choke out of rg58. Any would suffice, although the latter would need to a metre or so above ground. For the 5/8 I would recommend checking the design for the matching unit. Search MM0OPX's channel - Colin has made such an antenna.
what gets me is the rabid tribalism of the two parties espousing that one is significantly better/different than the other whereas as Tim points out there isn't actually that much of a difference. There also isn't a hard & fast limit on the exact 5/8th.
Rather than looking at "quantized" 1/2 wave & 5/8th it is worth looking at a continual smooth migration even from quarter wave (=2/8th =4/16ths) up through 7/16th, 8/16th (half wave), 9/16th, 10/16th (5/8th) & even 11/16th.
The starting quarter wave is pretty "rounded" with a fair amount of equal high & low angle (just nothing straight up). As you go up from 1/4 wave the high angle radiation drops down & concentrates into the low angle lobe as it moves out. There is no "switch point" between lengths as there is a smooth transition... HOWEVER.. when you start going past 5/8th the low angle "horizon" lobe starts to reduce again as a high angle "spur" then starts to grow (taking this to the extreme at full wave vertical you get the high angle "X or V" pattern).
One of the reasons that the 5/8th was historically preferred over the half wave was that traditionally the very hi-Z 1/2 wave can be a bitch to feed (decent big ferrites previously more difficult to obtain) & the 5/8th was much easier to feed..... I've still got my 1970's 145MHz Revco 5/8ths mobile whip what was the first "gold standard" improvement over the original quarter wave whip... oh how things have moved on since then via 7/8th & now dual banders.
The other thing to watch is all these computer modelling tools "perfection" is not 100% matching the horrible real world ground conductivity variation, real counterpoise/radial variation, adjacent metalwork interaction etc etc hence I can totally understand that someone may have had a bad practical experience with one variant but when they tried the other it worked better hence the "this works/that doesn't" tribalism. Others can have completely the opposite experience depending on their specific circumstances but neither is right or wrong for everybody.
"computer says YES, but your particular reality may say NO".
If we however don't go much past "5/8th on highest band of interest" (to avoid the high angle spurs starting to appear,) & then think of it multiband ... from Tim's calculations you are talking about just over 20 feet for 10m 5/8th (but as we have said even a smidge longer isn't a "showstopper" so 25' isn't outside the realms of the practical), then together with this radiator you need a matcher..... hey depending on what exact type of match you use you have just defined the comet vertical with its heat sink finned baked bean can feed on the base, or with a slightly different feed you have just defined the rybakov antenna or if you "double it up" for a balanced antenna you have just described the half size 5RV..... all they have done is pick a length around 20 to 25' to try and avoid a perfect 1/2 wave on any amateur band because of the difficulty in having their particular wideband matching from hitting that particular difficult high-Z.
You want another laugh... look at the feeding a half wave with the 49:1 vs 64:1 tribal debate... with very few mentioning that with a 2 turn primary you can have 14 or 15 or 16 secondary turns hence 49 or 56 or 64:1 (& if you have a 3 turn primary you have even more variability). Your wire thickness, ground conductivity variation, short counterpoise tail length, conductor diameter, exact length & adjacent metalwork will all influence which ratio YOU need.... there is no one universal answer to 64 or 49:1 for everybody. Tribalism is pointless.
You make some great observations… especially tribalism in the hobby. Thank you 73
Hi Tim , I have used both on ten .i didn’t notice much difference 5/8 seemed to have the edge on receive, but this could have been the greater overall higher.i am currently using a 5/8 mounted above a 5 element Yagi . Question would the yagi act as a ground plane,and if so how would this effect the take off angle?
That I’d need to look into .. unless someone can answer?
Fun fact:
All verticals are dipoles, but not all dipoles are verticals.
At first one will think, my fun fact is incorrect, even laughably stupid. However, considering that a quarter wavelength vertical must have a ground plane for it to function correctly, the second half of the dipole is the antenna ground plane which makes for an unbalanced dipole. As for not every dipole is a vertical, that is self explanatory.
Indeed
every ant on every band will behave differently in every location and times of the day, but if 10m is open , a wet piece of string would probably work anyway. the smallest ant is always easier to set up for me, and the smallest amount of power required to get a qso, is all thats needed. so many folk seem to complicate simple things.
Sorry got cut off again, therefore eliminating the use of such a big mast. Is it possible for you to do that test for real tim.
73 brian.
If I can get wspr working when out and about I’ll definitely do that Brian
Hi Tim,what's the best height I can put a 40m dipole up but only really need it for uk so nvis please? Sorry to go off topic n thankyou 73
Hi Andy for short hops around 500 miles or so then any height from 8 to about 40 feet would be ok. It isn’t until you get about 50 feet or higher (3/8 wave) that a dipole improves markedly for DX. My dipole is an inverted V.. 25 feet at apex and 7 feet off ground at the ends. Does well for inter G. 73
@Tim G5TM thanks Tim just watched an older video of yours explaining this:) do you get more noise the lower down it is or no difference? Thanks so much
I've used both and i.ll be honest work pretty much the same on 10 meters same height and same power slight difference is the 5/8 has a ground plane unlike the half wave.
Question what difference does the ground plane make on my 5/8 wave .
Is the ground plane those small radials?
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Hi yes the antenna is a sirio 2016 5/8 I also have the venom half wave same brand
@@Allthingsradio I think those radials are 70cm long each? I can’t think they are hugely critical for an antenna with a 20 something foot radiator
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Cheers Tim another question is why then do these antenna companies promote the aerial with the ground plane ?
Interesting!
Thanks!
If you model a 1/4 wave with a few elevated radials on a 12m pole you might be surprised at the pattern. It's nearly identical.
Given that a 5/8 really only has 1.5db gain over a 1/2 wave (and that's when compared over perfect ground etc.) The 1/2 is the obvious choice.
I've rebuilt my T2LT to your design specs and mounted it with the break in coax an exact electrical 1/2 wave above the ground and it's a DX machine. Just shy of 60 DXCC's worked in north/south America, Europe, Africa and Asia on 10. SSB, AM and FM with 5w and under so far this year.
Good advice and yes they are great antennas!
So which is the most important? Height or wire length? What if you mounted a 1/4 wave on the same pole, so mounted 9.5m up?
Good question. With the three antennas FED at the same height the 5/8 beats 1/2 that beats the 1/4. So, indeed if we put the quarter wave fed at 9.5m I SUSPECT (I’m not by my pc now to model this), that it may well be close to or actually beat the other two. However, unlike the 1/2 and 5/8 you’ll need at least 2 raised radials at 180 degrees to each other for an omni directional pattern. A bit more of a hassle.
@@timg5tm941 More hassle indeed. But if it was better, it would demonstrate than antenna height gain is more important than antenna gain if you had to pick one. If it was the same, or worse, that would be equally valid and prove more wire was better than more height.
@@Nick_G7IZR indeed it would. Another video perhaps ..
Likely inferior and laughably simplistic, but I have set up vertical dipoles for 10 meter band usage. The local forestry operates in ten frequencies from 27.750Mhz. I have also set up simplistic 10 meter vertical dipoles for home operators that use it from the 11 meter citizen's band through the entire 10 meter amateur band with marginal use on 12 meters with a small manual tuner. Primitive, ugly, simplistic, rather ungainly, but there are those that want me to set them up for them. Of course, a 10 meter vertical dipole will not work for mobile installation.
Good points
you can check how the same antena works at 25m over ground. i have one 10m delta loop at that hight. i have also one sky loop 160m and one ganmaster. 73 de sa6bzz
Sounds superb!