Debunking the Myth: Investigating the Noise Level of Vertical Antennas
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- Опубликовано: 27 авг 2024
- Are Verticals Antennas actually "noisy" - or are they just doing the job we asked them to do? Let's try and understand why this. Let me know what you think. I'm still not totally convinced eityher way. Discuss! Callum.
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My Classic is about 1 S point noisier than my EFHW fence antenna at 5ft off the ground. I have a very high noise environment around me and a huge retail area 1 block away. I spent months ferrite beading and toroid coring every appliance in my house that was making any noise. A friend even suggested I buy stock in ferrite production. I suspected the Classic might be noisier and it's true for ME. That being said, I have both antennas on a switch and if I find a weak station down in the noise that I can make out on the Classic, by switching to the EF the station is not readable. I've tested this dozens of times and the Classic "out hears" my EF every time. Even with the noise, my Classic out performs any other antenna I've ever had and that's what I wanted when I bought it. Thanks for developing this family of antennas and of course your great videos!! Jack K5FIT
Interesting analysis Jack. Thanks.
I have an almost identical setup and find the same 1 S point difference. My EFHW is also at 5' and runs in an L along my fence. I live in a rural neighborhood but there are 500+ houses w/in 1 mile with no real commercial facilities nearby.
Every ham has their own installation factors and use-case. For my situation, I find that in my small garden that a vertical is inherently noisier than a centre fed dipole or non-resonant centre-fed doublet. Irrespective of whether the vertical is ground mounted, elevated, a 1/4 wave or a 1/2 wave. The main bands where the difference is around 3 s points (vertical noisier than centre-fed), are 40, 20, 17 and 15. It's not until I reach up to 12 and 10 that there is a draw between a vertical and centre-fed for noise. Just my example you understand.
Tim.. It's SO difficult to quantify because to get the same gain on a horizontal antenna, you would need to be at east half a wavelength above the ground.
Great video Callum. This is something which I have pondered over the years & I think I have basically come to more or less the same conclusion as you.
I think verticals are fantastic in rural locations but in built up areas they tend to pick up noise (for the reasons that you mentioned in the video) & in my experience often struggle to get out due to other "clutter" (houses, sheds, trees etc) which make up your typical housing estate attenuating the transmitted signal.
A while ago I purchased an 18m DX Commander pole & mounted an EFHW vertical cut for 20m on top of it. The 49:1 feed point is at around 7-8 meters above the ground (above the roofline) & the difference between a ground mounted vertical was very noticeable!
It's still noisy at certain times of the day, although it seems to be reasonably quiet on the frequencies on which it is NOT resonant. Using the internal tuner on my FTDX10 I can get it working on 40m, 20m, 17m, 15m & 10m.
Performance is a little mediocre on 17m - 10m but it performs surprisingly well on 40m. It outperforms my EFHW inverted-V on receive (not sure about transmit, I suspect the horizontal antenna would win on that one but I haven't tested that theory with WSPR). It obviously performs great on 20m.
As is always the case with radio, I think my conclusion is get the antenna up as high as it's physically possible to do.
I'm also swaying towards non-resonant antennas for receive such as a Loop On Ground (which I believe is what you use), a high-Z vertical or maybe an RX only mag-loop (like the MFJ-1886). In my experience these have often been quieter than resonant antennas.
Just my 2 cents worth!
Yep.. I think every noise has a source..
My main antenna is a 135' endfed long wire running along about 14' above my fence. Works great. But, there's a ton of noise on 10 meters. Avoiding a long story, I installed a 10m ended wire antenna hanging vertically from a 30' extendo fiberglass pole. The coax connection is about 15' above ground and about as high as my house roof (which is 20' feet away). Amazingly, when I switch from my horizontal long wire to the new verticle 10 meter antenna, almost ALL the noise (viewable in my waterfall) is gone. I have been making way more contacts, including DX, with this simple verticle antenna. It is now my GO-TO 10 meter antenna!
Nice!
You just shipped my DXC a few hours ago... Can't wait to see how noisy my first HF vertical is! 😄
Hope you enjoy it!
Interesting topic. Very well told. Indeed a vertical does not have to be noisy but you need to put it in a large field without anything around it. A vertical near buildings is always a problem. I prefer dipoles at my base station but use a vertical when out in the field. I've had a multiband vertical in my tower for years and changed to a experimental multiband halo loop last month. The difference in receive is around 1-2 S units less noise depending on what band it is used. 73, Bas PE4BAS
Great work Lord Callum, l have to try that loop antenna and hear the difference. Keep safe 👍🏽
My 18 months of experience is that a vertical will pick up noise from surrounding properties very efficiently and needs to be properly earthed/grounded to minimise as well as carefully trimmed/tuned for the desired frequencies. Don't use a cheap un/un or balun or cheap co-ax and ground the transceiver and power supply. With a 1:1 choke at the transceiver end the noise floor should come down to acceptable levels and allow decent performance. All this counts for nothing if cheap solar installations and wi fi equipment spring up all around you. Ah well back to the drawing board lol. M7BLC
Nice video Cal. I have your DX Commander and a 22m loaded EFHW across the garden. I find that for a certain band, a certain time of the day, (etc etc) that one will be better than the other in terms of performance, RX, TX, noise etc etc. As a general rule the 1/4 wave vertical outperforms the EFHW for most criteria, but not exclusively so. Having an antenna switch is really interesting to switch between the two in any given QSO. Mark, 2E0MSR
Yes, A/B switching is fun./ Remember to test it on TRANSMIT with your caller, not just RX..
I made J antenna for CB 27MHz and it works really nice
Contrary to popular wisdom my vertical is far quieter than the horizontal dipoles/doublets that preceded it. In each case i have had effective common mode chokes. What goes under the radar perhaps is that in a smallish garden part of that horizontal will likely be close to the RFI from the house and maybe the nextdoor house too. A lot of traditional RFI sources have probably been the likes of televisions radiating up their coax, less of that around these days and none of the old issues from line timebases in CRT TVs. Of course in the past there was no DSL being carried by phonelines either. I am sure each case will vary.....
Yep, you are probably right.
phasing two antennas together works well to remove noise!
the mfj phase box works great!
Can you control that remotely with one coax to the roof?
@@mrtechie6810 need 2 coax runs. 2 identical antennas. Hope this helps
My vertical is dead quiet (unlike any horizontals that I've tried). I get regular VK and ZL contacts on the vertical, so there is no quibble from me
Nice!
I get a very low noise floor with a vertical. I use vertical for RX and OCFD for TX. Seems to be best combo, based on my ears and test geedback from distant stations. Sometimes I will not hear a station on the dipole, but can get S6 on the vertical.
Ah-ha!
It depends on the type of noise we are talking about. Static dissipation noise is an issue with all antennas due to it creating high voltage static discharge from the antennas but terrestrial noise from human-generated sources is another issue that can sometimes be remedied by another antenna being used to cancel out the offending noise via phase cancellation. Just information from my own experience and trial and error. LOL
Kindly explain how to achieve this?
Sounds like a good reason.👍
Question: why are the disc spacers not black? They would be less noticeable.🤔
Tried it.. They absorb too much RF.. Then 1,500W comes along on FT8 and we had fires.
I would LOVE ro see you make a mobile antenna, even if it's just for 20m-10m. I'm using a Yaesu ATAS-120A with my FT-891 but I'm really thinking there's something. better out there. (I'm primary caregiver for my disabled wife - precious little time to operate at home so, everything has been mobile.)
Love your channel. Many thanks for all you do!!
73's - Joe/WB3CFN
Joe, I COULD make one, but I would hate to think of the insurance I would have to pay!
@@DXCommanderHQ Nebula Extreme mobile antenna!!😆
“I’m not good at drawing crud.”
Lol! 😂😮😂
Good video! You did a good job explaining noise. My experience shows you are exactly right! 73s ND4A
I found some interesting details on W8IJ's pages.
"Noises arriving from groundwave sources some distance from the antenna are vertically polarized. This relatively fixed polarization occurs because the earth "filters out" horizontal components. Horizontal electric field components are "short circuited" by the conductive earth as they propagate and are eliminated, and since removing the electric field attenuates the magnetic field (they are inseparable in radiation) any horizontally polarized components from distant groundwave sources are quickly attenuated."
This probably explains why verticals are so noisy on low bands in tropical regions.
I use the same vertical on 160 and 80m for both my TX and RX.
With these, I have worked many stations in the Pacific on both bands.
My QTH is at 63 degrees north, and it is a quiet location (very few houses nearby).
The myth about quiet loops etc mostly comes from their ability to suppress common mode noise. Not because they are particularly quiet.
Control your common mode noise and know what is radiating and how height changes the patterns. Then it is not that many surprises anymore.
Yes, it's not that the man made noise IS vertical it's because they travel better. I think I mentioned that but couldn't remember the data. Thanks for that.
PS - Thanks for that data...!
You may have a point. My doublet at 1/2 wavelength above the groundhas a similar or the same noise floor as my vertical. The thing is, the noise is completely different! On the doublet its just a wide band hissing at s9 while on the vertical it is the classic power line noiseish sound at also s9.
As soon as I lower my doublet closer the the ground the noise floor lowers somewhat.
Yep, it's a strange science!
My personal experience is that its a mixed bag and highly dependeont on what is around you.
For example I have a DX commander quite literally 10 feet away from a ground mounted transformer.
That transformer is fed by a 14.4 kV primary which then feeds my house and the neighbours house.
I don't get any noise on that antenna despite being right next to a transformer like that.
Now I have a 3 element yagi for 10m and it's about 30 feet in the air and that antenna is noise city but also dependent on where it's aimed.
I also have a sirio gain master vertical that I use on 10m and its about 15 feet off the ground and it's not very noisy either.
Nor is my 10-80m off center fed dipole that's about 45-50 feet up.
Nice comment.
A lot of hams want antennas that don't work so well so they don't get noise. They're happy with what they get rather than striving for better because they are so averse to the noise. I've even seen RUclips videos with the operator showing the pan adapter where their low level signals drop with the noise when they go horizontal. The problem is the noise. Not the antenna.
Well, in which case (in light of your end comment) - it's both!
@@DXCommanderHQ with reference to the vertical.
I've run a vertical vs a dipole on the same band just for comparison sake many times. I never noticed the vertical being any nosier than my dipole was. Depends on your location and band conditions.
Good point.
I've used verticals for more years than I'd like to admit to and never had noise problems and I'm in a high noise environment. Keep them low, choked and if you can monoband.
80 meters is the only band that gives me problems which is surprising considering that I'm surounded by noise. Power Sub station behind me Main power transmission lines in front and a cell phone tower on each side. I can transmit on the 80 meter band but hard to receive because of 7 to 9 floor noise. Thank you for the idea of the receive loop on the ground. Also, I might possibly try a vertical to see if the noise is on a different plane
Do it. I have other ideas too. I will details those on another video.
Hi Callum, I thought that the reason verticals pick up more noise is because they receive on the same polarisation as what noise is transmitted i.e. vertical. I use an end fed wire, not vertical and I have a very low noise floor. I have no understand why. I am usually envied by other people and they don’t believe me until I video it then they say there is a setting wrong or something. 😂
I seriously doubt whether local QRM is only vertically polarised. When I say seriously doubt, it's more than that. I totally disagree actually. I thing vertical antennas are exceptional low-angle RX antennas. And low to ground dipole, loops, anything antennas are certainly not.
Great video Callum.... yes see if you can locate the null over the noise source.
I've always understood natural noise is mostly vertical. Man made can be horizontal. Instant switching from vertical to a dipole you can be caught out thinking your radio has gone deaf when on the dipole.
Being someone that works in broadcast. Its not unusual to see the spark gaps arc over on a windy day. A series fed tower can develop massive static charge. This opens a whole topic on how lightning works. To which I start the conversation with.... the zap.... is the end result. The thousands of amps does the damage.... BUT there is a whole build up charge phase that attracts the attention of the zap. Bleed this off... no zap! If this is a recieve tower it gets crackly as the charge rises. Not really of concern to an always on AM tx. The extra voltages does worry it... more so if its solid state. 73's
OK, some good ideas there. Thanks.. ZAP!
Hi call do you think with a vertical you lose out if in a small ish garden to it being up hight his the rf getting observed by other building ??? If at ground leve apposed to being on a pole 20 foot up in the air
I don't think so.. I have a short video coming out soon with my antenna about 10 feet / 3m from the wall of a house.. In Cornwall couple weeks ago.
@@DXCommanderHQ thank s callum my garden small and quite surrounded I will try a singel band home made vertical down there in the summer has im think on of the dx commander only other Consern his to get there I need 100 feet of feeder at the moment I have 213 in place to my aril
Hi Cal from an electronics and physics perspective (Don’t get me wrong I am far from an expert) I feel a good part of the problem with noise is that the antenna is too loosely coupled to the receiver. The noise is being mixed in the antenna element and the coax and interferes with the desired frequency you want to receive hence the noise is breaking though. If the antenna element/s is tightly tuned to the band the antenna acts like a band pass filter and there for well I think it will mitigate the noise somewhat. Think of 5/8th J type antennas if you put an DC ohm meter on them you will see a direct short however; they will pass signal quite freely at the tuned frequency. For good receive reception on HF it’s not the signal level it’s the difference of the signal to the noise. Just a thought, anyway I’m going to finish this bottle of red and off to bed 73’s.
Interesting... Let me think about iot some more! (hic)
@@DXCommanderHQ Cal did you get the video link I sent you last night re the Friday net?
Both atmospheric and man-made electrical noise is usually vertically polarized. This is from electrical storms, even high up and far away, where you can't see them and outdoor horizontal power lines (mains), which generally radiate vertical interference. Without distant electrical stoms and without power lines (or underground) noise should be much less. Antennas that are shorter for frequency have less, "antenna" energy and don't sound sound as noisy as longer antennas. A relatively short vertical is likely to have less energy on it than a long dipole, loop or long wire antenna and may be quieter, but it's the signal to noise ratio that makes the difference in hearing stations over the noise.
Hiya Jim.. So this part of your comment, "man-made electrical noise is usually vertically polarized". I have NO evidence of this. I've read all the papers.. But man made noise does not seem to be inherently vertical - now.. The MYTHS of eHam and QRZ forums say it is, but there is zero evidence.
@@DXCommanderHQ Here in America a lot of the 60 cycle AC power lines are above ground. Often, a steel support cable to the poles will generate radio interference and the government says the power companies are responsible for clearing it up. That interference is vertically polarized, as the RF from the horizontal power lines. Both the government and the power companies use RF detectors to determine the source and type or RF radiating from the power lines and associated hardware. It is well known, especially among ham radio operators.
Installation it on a noisy city apartment roof?
Does it use the coax as a counterpoise/ground?
It will work in a city. It can be noisy because ANY antenna picks up intentional noise.
The mission for the weekend is a Loop on the ground for RX. I guess it's all down to the signal-to-noise ratio. I need to catch up on Mike's vidjaos and wind some cores. Think I have got the wrong cores though. Bugger! I heard the stereo separation today on your live. Was that your classic and one of them LOG's? I am now in the capital city of noise as my neighbors have installed 9000 or so LED downlights in the house. Referee! Asking for a friend but how many Kilowatts through a Neboooola would he need to resonate and blow the LED's?
OK, so it wasn't a LOG, but a random loop of around 90m long with a 4:1 balun. My "LOG" has gone AWOL. I keep trying to find a day to fix it..! However, similar results. I did a video about it a while ago. Search "dx commander receive loop" or similar.
Verticals are not noisy, the just pick up more noise as I think a lot of household or local noise is vertically polarised.
Interesting observation but if you try and discover the evidence, you will find there is none. Only myths that members of eHam and QRZ forums seem to plunder. It's one of those myths that just goes on and on.. But if someone can show me the evidence, I'm all ears.
My 102" whip on top of my car is extremely noisy. It keeps slamming into everything as I drive around.
If you think you are getting too much RF in your antenna receive, just cut the coax. Nice and quiet.
Good idea! LOL!
I think, and this is just speculation mind you, if I have a dx commander and throw a banana at it, that banana has a greater chance of hitting that dx commander by a power of the diameter of the banana squared, regardless of the clockwise or counter clockwise rotation of the banana, Coriolis effect not withstanding. If I hit the dx commander, the score will be banana 1, dx commander 0 and vise versa. The one fact remains, regardless of banana impact, is that now I need to go buy another banana.
Or a bunch!?
@@DXCommanderHQ if we squirt some caramel on the DX commander and key down with a kilowatt precisely at the second the banana hits the radiating element maybe we can get some instant bananas foster?
The noise is picked up from the vertical run's of mains wire's, a horizontal antenna would have to be at the same height as the horizontal part of the mains ring to be as noisey. Vertical is vertical... That's how it was explained to me
It was explained to ALL OF US that way.. But it's a myth.
@@DXCommanderHQ is it a myth? I've not heard of it being explained that way before but then it's something that isnt talked about much.
Operating from an urban setting is noisey full stop for me! Like yourself I enjoy the low noise when portable with a vertical.
There is a modification for a receive jack!? This was my question! How do I receive loop with a separate TX antenna..Google 7300 mod... Thanks Calum!
Yeah, google it :)
Why is a full wave loop alot quitier compared to other antennas
I can't remember the answer to that one.. I have a feeling is that in the main, they are often lower to the ground (but there's another reason too.. and I forget).
Callum I think you are very close to the answer. If I use a vertical it can only be 40 feet from the house with a useless radial system. Yes S9 to S9+20 noise on 40m. Any antenna with a vertical element to it is the same. Inverted "L" is around S5. Windoms around S5. Bigest dipole I can fit in is for 20m so not a fare comparison as that band is less noisy anyway. Bottem line an empty logbook. If you can't hear um you can't work um. Nowhere to put a RX loop on the ground, tried it.
Oh hell, OK.. What about a TINY loop or even a dipole?
Man made noise is vertically polarized. A horizontal antenna will have a 20dB advantage in a noisy environment.
If you can show me the evidence that man made noise is vertically polarised, I'll eat my hat. Too many myths in this hobby sometimes.
Hi callum, what log software would recommend for an idiot? I've watched you on your live stream and that looks good, I have an alnico dx-sr9e and I'm sure you can connect it to a PC with the right cable. I'm not sure if it will work with any log software, you input would be appreciated. David
OK, so I started with WinLog32 (I don't know if they still do it). N1MM Logger just works for me. I can export to any other logbook, I can contest or DX, I can even do digital. The ONLY issue is that under the skin, it is HUGE. Be prepared to scatch away and find out what it does. It's insane.
Good stuff Callum and as usual your right ( I bet Wendy doesn’t say that too much) and there’s only a few things we can do to help out situations and hopefully we have nice neighbors 😁 de W9US
Thanks 👍
Nice video Callum. So the question is then..... Vertical or efhw in a small garden. I have both the vertical is a 20/40m. I have a corridor on open space East to west. My house and the house at the back is north and south. The garden is 8x8m which antenna would you use plus two small children running about?
Also have linked 20/40m dipole
Two masts to use 8m and a 10m DX commander
Motters M7TRS 73
Oh heck.. I would always personally aim at a vertical for TX and a small "thing" for RX. Kids and dogs.. I had them for years. I've worked around them.
@@DXCommanderHQ morning Callum. Yes I think you are right. I have had better luck with my vertical. It a homemade 20/40m with coil near the top so I can use both bands without changing anything, it has 8 5m radials which are not straight as not much room as the antenna isn't permanent thing so it up and down. The radials are probably in a rectangular box od about 2x4 which I can use while the children are in the rest of the garden.
When I tried the efhw I had it going up the dx commander 10m the across the garden to the roofline bet the neighbours thought it looked amazing 🤣🤔
I have not shack St home so it's a popup station which is a Ft817 a run of rg8x to one of my three antennas I've made. I am a portable ops but it's nice to be able to spin the dial (little dial) at home.
Have a good Sunday mate.
Motters M7TRS 73 👍🏻
But you didn't address localized XYL noise.
Good point. Buy some soft rope Ed!
Excellent response Callum!
I thought he was going to say noise canceling cans...
can I fix dx commander up my roof haven't space in my Haus
Lots of people have.. But make sure you can get to the roof, so only a flat roof that is easy to get to and maintain because I never considered folks doing that.
@@DXCommanderHQ thanks I will be sending some pictures
THIS IS MY OPINION IF you have static and EMI / EMC Static noise in built up area Just ground everything," Just go MAD" earth rods, earth blocks ground all your gear, lighting surge protrectors are a excellent way to ground your coax points ! dont worry about radials then load it up yeeehaaaaaahhh
Well, nothing wrong with earth rods - but they will have almost zero effect on transmit efficiency.
I prefer verticals, much easier to deal with