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How good is a G5RV and how do they work? Ham Radio Antennas explored

How good is a G5RV and how do they work? Ham Radio Antennas explored


Ah! Welcome back to the Bunker. My name’s Callum from DX Ccommander callsign M0MCX and I was pondering last night how G5
RV actually worked now if you don’t know what G5RV effectively it’s gotta be a
picture on here somewhere well that’s the original article from if we scroll
into this you’ve got this hundred and two foot top and so it’s 51 feet or
about fifteen and a half meters per leg with a bit of ladder line coming down
the bottom and all the dimensions are complementary to each other
there we are because a hundred and two foot doublet okay
just fed with ladder line to a big balanced tuna would work fine and it
just so happens that if the length of the feeder is just the right amount the
impedance transmission transformation between the feed point and where we plug
a coax in brings it down to that perhaps three to one SWR in other words we’ve
got maybe quite low impedance might be quite high impedance it’s not perfect
for coax it’s good enough now the one I bought when I was a youngster in this
hobby I’m not quite sure if it had there was a little bit of shrink wrap where he
sort of an S so to 3:9 I could pluck my coax in I don’t know if there was a
ballon in that it’s a bit small to be honest if it was if I was building one
I’d want to put a massive choke in there greater than eight thousand ohms big
every joke to make sure that all my RF wasn’t then also being radiated all
along the outside of the coax as well so how does it work is that we’ve got this
not bad match to 80 40 and 20 and with an 80 you of course it’ll go anywhere
but so would anything you know you could put coat hanger in and probably tune it
with a nice tuna so that’s how it works but let’s just head into em
ma na that I just want to plot this to show you that I think it gets kind of
live streaming gets kind of bad press sometimes but it doesn’t have to be so
here we are if we just so that’s this is the aerial look can I just assume in
here yes I can take the currents awful ways I’m going everywhere so I’ve built
effectively an inverted V and each leg says here length is 15 and 1/2 meters
long so it’s g5r V sighs well I’m not modeling is the ladder line coming down
the middle that has absolutely no bearing on what the the plot would look
like by the way not at all doesn’t it’s irrelevant that I’m showing SWR of 183
because by the time you fit your transmission line you choke barren and
bitter coax everything they’ll probably be about three to one but again it would
be irrelevant as long as we’ll get an RF into the top you’ll be working you see
so I would imagine on 80 meters we just have a bubble of RF and I’ve modeled
this 10 10 meters off the ground okay so 10 meters off the ground
sure enough we’re getting this bubble of RF look so fine that’s through the
middle all the way through here and the aerial is built with the center point
here and one leg going that way one leg going that way and this is the bird’s
eye view so at the top here I’ve got four point three apples and inside I’ve
got six right so I’ve got slightly more gain off the I never know where you
sides edges or whatever but through the aerial if you know what I mean so that’s
fine their owner probably we’ve got a stand similar on 40 meters maybe a
little bit oops I interrupted it maybe has a little bit more pronounced yaaasss
so I could we can look at that in 3d look
so that’s from the crow and then that’s just walking around it I can think move
that down come on yeah and I’ve now got two point four apples because this is
all relative doesn’t matter if it’s two point four oranges bananas its dbi as it
happens but the difference between there and there it’s six point three so it’s
slightly more pronounced through the bridge if you know to me if we go to 14
say point to give or take weirdly enough we’re actually not showing a bad match
here look see that two point four seven but again that’s irrelevant
so it’s getting this elongation is becoming more pronounced and if we look
at the far field plot so what are we saying right so through the aerial did
you see that’s interesting I didn’t know this I’m running this before I just
quickly built it before later film and trying to see what this is doing so
through the middle we got these big three lobes coming up north to south
effectively let’s just take a cross-section at say 10 degrees off the
horizon okay so DX would be off the corners here what about five degrees
five degrees regulars will know he’s always my baseline I like to base things
at five degrees because I know a half regional vertical will give us minus
five apples or DBI mines so in fact crikey
– four and a half so nothing to write home about I’m afraid what about at
10:17 meter band now they say you shouldn’t be using this on 17 meter band
because he has WR is a bit too high on the coax but then we’ll find out won’t
we – two point seven so it’s not bad actually it’s about 3 DB better looks
bloody weird that doesn’t it what does it I don’t know make your mind
up some of you got g5r V I’m sure I don’t you know listen when conditions
are right they all work done they 15 I wouldn’t use this any higher than 15 if
you want to that’s fine at five degrees you know it’s not really working very
well you’ve got the equivalent of a vertical there oh I don’t know it’s
about sixty be better than a vertical there and they’re off these corner
points here and just for the hell of it twenty-eight point five elevation five
so where’s two two point three so it’s pretty good I wonder if anybody’s ever
used this right up here 50.5 what’s that their families in it far field elevation
whose doesn’t need testing six point three you’d be lovely to use this on one
of these activity night contests and people say so what early using so I got
a g5 RV at ten meters now I’ll be funny wouldn’t it so hmm
alright I’m now I’ve got to say this Lewis Lewis Barney says major loads of
vertical component in the polar diagram tend to be lowered as the operating
freely enough that’s from 14 mega hurt here we go most of the energy radiated
in the vertical plane is an angle suitable for DX working I’m sorry to say
this by actually think mister varley’s wrong I can’t see why anything would be
vertically polarized in this antenna at all and I think a lot and one reason
we’re having this debate by the way is I was overhearing a couple of old-timers
debating the fact whether there was any vertical radiation component ology vive
RV or not they couldn’t make their minds up but I’m telling you now there can’t
be it’s balanced feeder balance feeder does not radiate all the
old-timers know that and I think it’s because people see a lot of these
pictures and I’ve got no one here I see a lot of pictures with people not Smith
chart showing the idea of of well here we are this is page three of his a thing
is yeah page 3 of his document and and we see all the time that does radiating
component in a vertical field I’m sorry it can’t do that mr. Varney and I wish
you around so I could talk to you about this and what you thought it might be
doing but it doesn’t okay so there we are
have I covered everything oh yes of course you can go half size you can go
from 51 feet to 25 and a half feet and per leg and that will give you
definitely 40 and 20 but on the other hand you could have a fan dipole I don’t
guess it’s up to you isn’t it well is that boring video or what but anyway I
just want to demystify very slightly the g5 RV it’s just a doublet with the
ladder line being the matching section – my name’s Callum from DX commander enjoy
your radio I’ll see you in the next one bye for now you

58 comments on “How good is a G5RV and how do they work? Ham Radio Antennas explored

  1. Happy New Year Callum [for tomorrow]. Great video again. As before, I like your videos as they are addressing subjects that are not discussed elsewhere… For example G5RV performance (and its half size variation) isn't necessarily as claimed… [it's got the press though, and new-comers (and others) tend to use the 1/2 size in restricted spaces). So, is the G5RV simply a compromise antenna with good publicity? 73 Cliff

  2. Brilliant – as always Callum! Interestingly, I have the full size G5RV and use it regularly on 17m (To talk with a friend in Slovenia) and also 10m ssb (not sure about VHF though??) – Had really good QSO's from the Faroe Islands and Pisa Italy on 10m ssb
    last couple of days and both frequencies tune really well on my ATU. As you say it's all down to conditions? One thing you may possibly know, why on one day it tunes well on say 'J' on my inductor.. then another day it is 'C'? Most strange..

  3. I was headed down the G5RV route this past spring after listening to some greybeards grousing about theirs one evening on 40. It seemed way to good to be true – and thankfully the guys at DX Engineering talked me out of that and into a fan dipole. Man is that fan dipole great. I was in a tiny suburban backyard without much elevation. Had maybe a 45 degree spread between the two poles of the antenna at 25 feet up and it still got up and out. Fantastic on 40, 80 and a little bit of 160. Love it. Can't wait ti get it back in the air at this new house with a big yard and a 60 foot tall tree to run it out of. If the winds stay calm, a buddy is bringing his drone over today to help me throw a (blah) zep in the air for time being, because some wire is better than no wire, but I'm really longing to get my fan back. 🙂 Thanks as always for another well produced and educational video!
    -Bob W8SDF
    (coincidental aside: my second choice vanity call was W8MCX.)

  4. Very interesting, I used to think – skewed by the G5RV article that the feed line formed part of the antenna but it can't do and it may have been a misconception because G5RV rightly showed the current distribution up the feed line giving that impression. 

    Incidentally, I had a G5RV before my hustler 6-btv and it had a long length (10M) of coaxial before a sealed plastic tube (maybe a balun) before the 300-ohm ribbon up to the dipole centre. Your video triggered me to read some more into this long coaxial addition and it was to attenuate (especially) the reflected RF and reduce the VSWR so that modern rigs could cope with the load mismatch – no more than 2:1 or 4:1 if combined with a typical internal ATU, so really the coaxial was masking a poor impedance match. Noting, that same coaxial attenuates the forward wave too, so making the overall antenna worse!

    That said, the G5RV is really low cost and is easily made and for most newcomers its a quick antenna solution to get them on the air and so deserves its place in history for that.

  5. I've worked Crete on 10m using a G5RV. I'm new to HF so relying on you guys educate me. Got a long wire here also…the G5RV out performs it on most bands …not 160 though

  6. Actually, I think it may radiate in vertical polarisation above ~20Mhz in some circumstances, but thats not because of feeder line – it simply could start working as really bad beverage antenna. I saw this effect when used 20m dipole on 70cm band by mistake – I've got surprisingly low SWR and directivity towards dipole ends. I think that happened because of either my dipole was slightly unbalanced or my balun was unable to get rid of common mode current at such high frequency. Experiments showed that it had the same gain as my 1/4 for this band and vertical polarisation. But I can't know this for sure – this could be coax feed leakage reflected from water surface of the lake that was near tx and rx point… Anyway, reception was too good for feeder leakage

  7. I used a half size G5RV early on when I first got my ticket (mainly due to lack of space in the garden ;-( ) and never really had much luck with it. Next HF antenna was a wire loop antenna which worked a lot better (fed with ladder line into a 'Z Match' ATU). I ended up cutting the wire of the G5RV up for elements for a home brew, 8 ele' quad beam for 2 mtrs…. that worked great, so the G5RV ended up useful in the end 😉 73

  8. Happy New Year Callum! As always another great video. I borrowed a G5RV from a fellow ham just to try it. not impressed. I compared it to my fan dipole, same height, same direction. Fan Dipole much better. mine is 80-40-20. here is a link to a good article on building them. Pay close attention to the spacing…. http://www.hamuniverse.com/multidipole.html

  9. Cal, I use a G5RV as my main HF aerial and I get a lot of flack for using it. I have nearly 1000 logged QSOs with it. I enjoy your videos! KX4EZ

  10. Had a g5 I made when I got licensed first. It was mediocre at best. I modded it into a ZS6BKW, a truly magnificent aerial on 40 meters, where I could fire 400w into it with the tuner in bypass

  11. Hiyas Callum Happy New Year ! Thank you for your videos they are informative for someone like me new in the ham club lol…keep up the awesome work !!😁👍KM4WRG

  12. I have one about 40ft in the air. It satisfies me for what it does, I’ve worked dx on it since I bought it in 2015. 73 and great video-K0WKT

  13. You are right – the ladder line is not radiating! But I think the antenna is still practical in limited space environments 🙂 Rgs 73 de HB9GNK

  14. Happy New Year!!! Never commented on YT before, but wanted to let you know that informative AND entertaining works! 5 min. + not a problem. 73 W4IHC Richard

  15. The ladder line he calls a makeup section. It's basically a phasing line. It determines at what stage the wave is when it reaches the center of the radiating element. The idea is to accommodate enough half wave or quarter wave sections prior to the radiating element and it makes a difference as far as the propagation. You may also want to look at the backyard inverted V which comes stock in that software as almost everyone I know sets up the g5rv as an inverted V. Although I don't. You should check out a couple YouTube videos they are part one and two of the same talk from the horse's mouth you can't talk it over with him but this is about as close as you can get:

    https://youtu.be/4-6Gq5Od6m4

    https://youtu.be/HnZiEMb-gzE

  16. my G5RV jr. 10-40 in less than a year working only on weekends for about 10 hours mainly digital ft8,cw, rtty 2110 contacts including 95 countries mainly 20,30,40 meters using the icom 7600 and build in tuner less than 30 watts. antenna high 15 feet in my back yard. conditions have a lot to do with it and some operator skills…

  17. HI Callum, NO, not boring at all. I enjoy your videos regardless of your topic. I like your approach to your subjects, its like we are there talking to you in your ham shack. I have just found you recently as I have been off the air for about 5 years. I got my licence in 1976 and dabbled in building things (800 watt amplifier) but far from what I would call proficient in the field. Thanks for your videos Callum. Cheers Dave VE7CMI

  18. Nice info. Scrolling through your channel ( subbed ) while freezing rain is falling. I've had a General class license for a few years and I've learned more from watching your channel than from any of the forums. Cheers, de W5 IJH

  19. Hi Calum. Same has G6EJD, I used to be under the same impression that the G5RV radiated partialy from the the upper portion of the twin feeder on the lower frequencies. It makes a lot of difference now having a computer where we can see what the radiation patern is from any type of antenna. My god I have read so much bull regarding the G5RV from different sources, it used to send me crackers. I am sure Varney first developed the antenna to be fed with open wire feeder straight into a ATU as per a doublet ?. When using the halfwave, 30ft of feeder at 20m the antenna becomes a one and a halfwave centre fed for 20m which is approx 90 ohms feedpoint to 90 ohms at the bottom. So you were advised to use 70 ohm twin feed from there or 70 ohm coax. I was going to get some 100ohm twin feed . Somthing like a quarterwave at 80m and give that a try to 50 ohm coax, but never got round to it. I did make some good copies using the G5RV has a inverted v up at approx 50 ft in the centre. Then the wind got it and I said goodbye G5RV. I could not be bothered to make another. Carry on the good work Calum. 73 de John – G)WXU.

  20. Hi Callum
    Just passed my exam and have bought the G5RV half size as I have little space, I have it mounted on a 20foot pole and it is an inverted V but could you or anyone tell me if it would be better to make it a flat top.
    Cheers Greg

  21. No, not a boring video at all, Mate! I was really curious if I could make mine a (somewhat slighty) inverted V and get away with it; it's so often seen as a T config. Now, I just need to make an "Ugly Balun" and I'm on the air – better! Thanks and 73! Oh yeah, will an MFJ – 949e be a sufficient tuner – I'm only running 100w?

  22. I used a home made G5RV over 40 years ago with ladder line into 75 ohm twin then into a short length of coaxial cable. It is only a 20 M aerial and a compromise on any other band. It was quickly replaced with a nest of dipoles fed with twin feeder into the shack then into about 6" of 50 coaxial cable and a soldered PL 259 plug straight into the SWR bridge and no ATU. It worked all bands with a very low SWR and out performed the G5RV.

  23. Would a fan dipole on 20-40 be better at radiating than a G5RV Jr? I'm thinking about making a 20 – 40m fan dipole before winter time. I don't have the space for an 80. 🙁

  24. G5RV wanted the antenna installed as a flat top dipole not inverted V. It is just a dipole with a clever feed that allows using it on at least 3 bands or more. Bill Orr (another old timer) said put up a dipole as long as you have room for and as high as you can. feed it with open wire line and a balanced tuner. Away you go.

  25. yes there is vertical radiation and not from the feeders. when used on harmonics radiation coming off the top in line with the wire is vertical and other lobes are a combination of polarization. Verticals have a horizontal component as well when used on harmonics but the radiation is almost straight up and pretty useless.

  26. hmm.. i used to use a G5RV well i soon chopped it to bits to make a dipole cut to the size of my small garden, then i gave up and run a long wire 1/4 of it going up in the air then over the other side of the garden (40ft long) this was going to an SGC230….
    first off the "any extra dbi" you measure in that program will be used up from the tuner, this is the biggest problem with the G5, you need a tuner to get 1.5 or better, yes i know you can run radios at a SWR of 2 but its power is coming back to you and not out of the antenna…
    you are correct about the feeder line not being able to polarise because its balanced feeder, yet without no choke or rf ground the lump of coax braid could become part of the antenna which at a 10m height there will be some coax run vertically ….
    in my hay day of playing with this i did find some weird things happen as if the very ends of the dipole change polar and just folding them down as a micro inverted L a few inches at the end where you tie at the dogbone brought it back in line, this was so dramatic sometimes it could be heard in realtime when moving it! thus i didnt test the SWR and i didnt have an antenna analyser to see what it was doing for the induction…
    all this was about 20 years ago, i used to pirate back then lol but became licenced when i got bored of HF and started taking a liking to S/UHF and how oxygen molecules in the air will attenuate the signal but what is funny is if you got a mass of water (cloud) you could actually bounce your signal off it!
    now if you want interesting, look at how the magloops work 😉 so very small footprint for HF that in some cases its smaller than an antenna for the 2m band but still works with "gain!"

  27. Boring ? Not in the least. I learn something from each video of yours that I watch. If I am ever in England I feel like I am obligated to buy you a beer. Take care.

  28. Callum, love your videos, I think the myth of the balanced feeder radiating is because initially no-one did anything to kill the common-mode current. Of course the radiating feeder is not all bad news… but bad news for RFI problems etc. A few years ago I did some experimenting with baluns, quite a novelty to let the amplifier heat the room and get zero RFI complaints. Properly utilised balanced feeder does not radiate, it is only accidental issues with the system that will cause it to.

  29. so what is the use of the ladder line then if it does NOT radiate ? why not put a balun on top instead of the ladder line ? wouldn't be the same ?

  30. I love these videos. Any chance of modeling the extended double zepp? Tried to do it myself but I can't seem to get it right. 73

  31. I was fortunate enough to hear Louis Varney (G5RV) give a talk about his antenna design some years ago. He said it was poorly understood by most commentators who claimed it was either the best thing since sliced bread, or the worst design ever. The reality is that it is a compromise antenna, as most are except a fully resonant dipole.

  32. It has probably been covered in the comments, the ladder line can radiate if any imbalance current is present, the original design used coax to feed the ladder line. A decent common mode choke would let it work more like a doublet, I suspect the feeder radiation might fill in some of the low angle stuff..

  33. He is WRONG and Mr. Varney is CORRECT. depending on the frequency (and not at 20 meters), part of the ladder line is an inductive stub matching transformer and part of it is actual antenna radiator as follows:

    OPEN CIRCUIT STUB: INDUCTIVE

    j is the imaginary unit,

    Z0 is the characteristic impedance of the transmission line,

    λ is the wavelength, and

    l is the length of the line (in the same units as the wavelength).

    An open-circuited stub is the same but negative:

    −j*Z0*tan(2πλl)

    So depending on the frequency, part of the ladder line "assumes" the role as a stub for the antenna "feedpoint" to match the impedance of the antenna with inductance (length of conductor). For different frequencies, different lengths of the ladder line are used as the antenna. This is why the length of the ladder line is critical and anything other than that is simply a doublet antenna fed by ladder line.

  34. You don't need a choke (or a balun) which massively degrades performance. Just a simple antenna tuner works well. Also the top horizontal section is not a "doublet". (It's a 3/2 lamba dipole at 14MHz approx).

  35. Thanks for the great explanation of the G5RV antenna! I have one here at the QTH and it just works, on 80M-10M running stock 5W QRP and stock 100W I'm killing it with contacts on HF

  36. You are absolutely right, they got me on the wrong track too. Your explanation is exactly what I experience using this antenna for a long time now. As for using it on 50MHz, I have done it and worked several stations in USB a few thousand KM's away. As for the massive common-mode-suppressor, yes that IS A MUST! I use 3 meters….no joke….of fer-rite-clamps to get rid of them. With 100W just 1m is enough, with 1KW 2m is enough…..to be sure 3 meters! Never have any problems and always get massive signal reports. Also checked myself with WSPR, using just 1mW, it does work and work well.
    This antenna is totally wrongly calculated by most and Louis was just lucky. That is my opinion too. BTW I feed it with Aircell7….people call me nuts…don't care.

  37. Great show. Studying for my tech license. I'm a 2.5 year retired multidiscipline engineer from the military contractor communications industry. I just installed a MFJ-1778 101 ft dipole 35ft high with a Radiowavz BISO balun today. I'm using a Hammarlund HQ129X receiver. It seems to be working great. Picked up some guys arguing over nothing around 7mhz. Also WWV atomic clock around 15mhz. Looks like this boat anchor will take a little practice.
    I'm no expert but it looks like I came up with a pretty good approach for my installation. Watch "11-8-19 I CAN HEAR YOU NOW! Installing a Dipole G5RV Antenna With BISO for my Hammarlund HQ-129X." on YouTube
    https://youtu.be/4HdKOw_fg7o

  38. Thanks Callum for another great video . With the help of your well explained vids I’ve just passed my foundation licence.

  39. I prefer Delta Loops to be honest, get more 'antenna element' up in the sky in a nice flat triangle or rectangular configuration into a 4:1 balun parallel to the ground. Seems to work with minimal VSWR on 40, 20 15, 10m.

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