I’ve been doing some antenna modelling and comparisons for John, W2VP comparing some phased and parasitic arrays. One of the phased arrays I modelled was an End-Fed-Half-Wave (EFHW) phased vertical array for the 40m band. It’s got such a nice radiation pattern that I thought I’d add it to my antenna pages here on the website for others to read too.
M0AWS 40m Band EFHW Phased Vertical Array Antenna View
The EFHW Vertical Phased Array is as simple as two vertical half wave wires both of which are fed via their own 49:1 Unun. Wire 1 (radiator) is exactly 20m tall and wire 2 (reflector) is 21m tall. The space between them is exactly 10.5m.
This simple antenna arrangement gives a surprisingly good radiation pattern with a reasonable forward gain and front-to-back (FB) ratio.
M0AWS 40m Band EFHW Phased Vertical Array 3D Far Field Plot
The antenna has quite a wide beam width which is to be expected from a pair of phased verticals. The nice thing about this array is that it has very little in the way of high angle radiation. This makes this antenna ideal for long distance communications. This isn’t an antenna for local chatter!
M0AWS 40m Band EFHW Phased Vertical Array 2D Far Field Plot
The 2D Far Field Plot shows that the antenna has a forward gain of 3.16dBi at 19 degrees. This is some 8 degrees lower than a typical 1/4 wave vertical phased array. The array also has a very respectable front-to-back (FB) ratio of 20.53dB.
Both elements in the array will need to be fed via individual 49:1 Ununs with the reflector requiring a feed phase angle of 100 degrees. A 100 degree phase angle gives better performance than the typical 90 degree phase angle that is typically used for 1/4 wave arrays.
For such a simple design this antenna should give great DX results as long as you have the necessary supports for the two vertical wires and the space for the guy lines. If only my garden was much bigger and I had some large trees to hand!
Summary:
Radiator (Element 1): 20m Reflector (Element 2): 21m Reflector Feed Phase Angle: 100 Deg Wire Dia: 4mm Feed Type: 49:1 Unun on each vertical element and a phasing harness Impedance: 50 Ohm SWR: <1.5:1 across whole band
Over the years I’ve built many multi band vertical HF antennas including multi-element quarter wave verticals like the DXCommander configuration, multiple end fed vertical dipoles all on the same pole and a host of other configurations. As with all multi band antennas there’s always a compromise, on some bands it performs well and on others it doesn’t, it’s the nature of the beast.
For some time now I’ve been using a multi band vertical antenna that has over the last year performed incredibly well on all bands from 80m to 10m. Don’t get me wrong, it’s not perfect however, it has out performed every other multi band HF vertical I’ve tried to date even though it’s by far the simplest antenna design and according to the antenna modelling software I have it shouldn’t be as good as it is.
So what is this magical multi band HF vertical I speak of? Well it’s nothing more than a piece of wire 13.4m long taped up a 12.4m vertical Spiderpole with 1m of wire tucked down into the top of the Spiderpole.
Obviously this is not going to be resonant on any band without some sort of impedance matching circuit at the bottom of the wire. Originally this antenna was my end fed half wave vertical antenna for the 30m band that was fed via a 49:1 Unun. This antenna worked incredibly well on the 30m band allowing me to work DX globally with ease but, it was a single band antenna and I wanted a multi band solution.
I decided to remove the 49:1 Unun and replace it with a home brew LC circuit made up of a coil made from 5mm copper tubing and a large air spaced variable capacitor I had laying around from an old ATU project I built many moons ago.
This simple LC arrangement at the bottom of the wire worked incredibly well and tuned the wire from 80m to 10m with a perfect SWR on each band using nothing more than a ground rod and 4 x 12m radials. Performance was surprisingly good on all bands 80-10m giving me the ability to get some DX stations that I’ve never been able to hit before. The only drawback to this solution was the fact that I had to go out and manually tune the antenna every time I wanted to change band. Not so much of a problem in the summer but, in the winter in the pouring rain and howling wind it’s no fun at all. (I resolve this issue further down in the article!)
Multi Band Vertical HF Antenna using a 12.4m Heavy duty Spiderpole at the end of the garden
Performance on the HF bands is incredibly impressive with this antenna. Modelling it on EzNEC software it shouldn’t be that great on bands above 20m however, it seems to defy the modelling software as it performs amazingly well on 17m, 15m and 12m, better than any other vertical antenna I’ve made for those bands. How this can be I do not know, normally my antenna builds match closely what the modelling software shows but, in this instance it doesn’t and I’ve really no idea why.
Multi Band Vertical HF Antenna showing loop at top and wire tucked down into pole
Always wanting to put things into perspective here’s some details of the contacts I’ve made on each band showing how well this antenna has performed over the last year or so.
Firstly the 80m band, I’ve not used this band much over the winter months as I’ve got into the higher bands however, the map below shows all the stations worked on 80m using this antenna.
Stations worked on the 80m band from the M0AWS QTH
There are 51 contacts in total, not a big number by any means however, there are some good distances made with contacts into North America, South America and Indonesia. I’m sure I could had done better if I’d spent more time on this band, something to aim for next winter perhaps.
Next is the 60m band, a band I really like and have enjoyed over the winter months. The antenna performs incredibly well on this band even though we have very limited access to 60m here in the UK. With 288 contacts in the log with a good spread of distances I’m really pleased with how this antenna performs on this band.
Stations worked on the 60m band from the M0AWS QTH
Moving up in frequency the 40m band is the next one on the list, this is a great band and one that I’ve loved for many years. I’ve spent countless hours on CW on this band in the past and worked some great DX. The performance of this antenna on the 40m band is excellent, if I can hear the DX normally I can work them regardless of where in the world they are located. With 226 contacts in the log spread globally over the winter here in the northern hemisphere I have no complaints about performance of this antenna on the 40m band.
Stations worked on the 40m band from the M0AWS QTH
Moving up onto the 30m band I have to admit this is probably my favourite band of all. I’ve spent so many hours on CW working some of the best fists I have ever heard on the air I’ve grown to love this band not just for the DX available but, for the quality of operator found on this narrow piece of the RF spectrum. Needless to say since the antenna is a half wave on the 30m band performance is stunning, out performing any other 30m band antenna I have ever made. It’s even better than the 30m Delta Loop antenna that I built and used when I lived in France.
With 467 contacts in the log on the 30m band you can tell this is my goto band and one that offers access to some of the best DX in the world.
Stations worked on the 30m band from the M0AWS QTH
The 20m band is a band that I never really used until I moved back to the UK from France. Living in France I had acres of land and so I was very much into the low bands, 160m to 30m and never ventured above this part of the spectrum. Now living back in the U.K. with a typical U.K. sized garden the low bands are much more difficult to get onto and so my interests have moved up in frequency somewhat.
Getting onto the 20m band I was amazed at how easy it is to work DX stations compared to the low bands, it’s simply a case of if you can hear them you can work them, there’s no real challenge to be honest. Because of this the band is always super busy with people shouting over the top of each other to get the DX. Not to be put off, I’ve made a surprising 412 contacts on 20m covering the globe. This antenna works incredibly well on this band and you really don’t need anything else to work DX on 20m.
Stations worked on the 20m band from the M0AWS QTH
Next is the 17m band, one of the WARC bands that I’ve never really ventured onto until now. I have to admit I really like this band, when it’s open it’s normally open to the world all at the same time. With an almost undetectable background noise level you can hear the faintest of signal on this band. This is one of the bands that according to the EzNEC modelling software this antenna shouldn’t be any good on but, I have to say that it’s performance is beyond anything I ever imagined. I’ve worked my longest distance yet on this band and with this antenna, ZL4AS at 11776 miles, a distance I haven’t achieved yet on any other band. The 17m band really is a great band, I’d actually say it’s better than the 20m band even though there is considerably less spectrum available. With 220 contacts in the log it’s been a fun band to use.
Stations worked on the 17m band from the M0AWS QTH
Continuing the theme of the WARC bands, the 15m band is another one that I’ve only discovered in the last 12 months. It’s only now that I realise what I’ve missed out on due to my addiction to the low bands for so many years.
I’ve only made 76 contacts on the 15m band, not a lot at all really. This is mainly due to the fact that I get easily side tracked by the 17m and 30m bands most of the time and the radio VFO never gets as far as 21Mhz. Performance of the antenna is good on 15m, I would say not as good as on the 17m band but, it’s no slouch by any means.
As you can see on the map below, I may of only made 76 contacts on the 15m band but, they are spread right across the world proving that this antenna’s DX-ability on 21Mhz really is rather good.
Stations worked on the 15m band from the M0AWS QTH
Finally we arrive at the top of the WARC bands, the little 12m band. Once again this band is very much like the 17m band, super low background noise level, when it’s open you can work huge distances with very little power but, often there is quite deep QSB that can make getting that elusive DX a bit more challenging.
With only 66 contacts in the log once again I’ve not spent a huge amount of time on this band but, it hasn’t disappointed. With global coverage from this antenna on 12m once again I am astounded at how well it works. With software modelling saying it should be terrible on 24.9Mhz with nothing but super high angle radiation, it really shouldn’t be a good antenna for DXing on this upper WARC band but, it is and I have no idea as to why!
Stations worked on the 12m band from the M0AWS QTH
Finally we arrive at the 10m band, another band that I have never got into even though many refer to it as the magic band. This is the band that I’ve made the fewest contacts on, not because the antenna doesn’t work at the dizzy heights of 28Mhz but, because I hardly ever get the VFO dial past the lower bands due to the level of DX available. I really should make more effort to get the best out of the 10m band, especially now the summer is coming.
With a measly 19 contacts in the log I should be ashamed of myself for not doing more on this band as it is very often open and busy with traffic. Since I’ve not really used the antenna that much on the 10m band it’s hard to say how well it performs however, I have had contacts into North and South America and so it shows potential.
Stations worked on the 10m band from the M0AWS QTH
As you can see, the performance of this antenna is self evident from the log entries, it works superbly even though the modelling software says it shouldn’t above 14Mhz. This is now my main antenna here in the U.K. and I’ve only made one change to the initial setup and that is to add a CG3000 remote auto ATU to replace the home-brew LC tuning circuit.
CG3000 Remote Auto ATU housed in a plastic box
With the CG3000 auto ATU in place I no longer have to venture out into the cold, wet garden in the winter months to change band, it’s just a case of sending a continuous 10w signal into it and leaving it to tune in less than 2 seconds. The CG3000 is a Pi Network ATU so it handles both high and low impedance loads with ease. A Pi Network ATU is one of the best you can have, I’ve made my own in the past and had excellent results.
So in summary, 13.4m of wire vertically up a 12.4m pole with 4 x 12m radials, a ground rod and a CG3000 Auto ATU will give any HAM station the ability to work DX on all bands from 80m to 10m without ever having to leave the shack to tune it.
Since I got the CG3000 off of Ebay for a bargain £170 and the 12m heavy duty Spiderpole for under £100 the total cost of the antenna is considerably less than many commercial offerings available and yet performs as well if not better.
If you want to get this antenna onto the 160m band then you just need to add a small coil into the mix at the bottom of the wire to increase the inductance in circuit. The CG3000 will then happily tune the entire 160m band. It’s best to remove this coil though for all the other bands otherwise performance is reduced.
Please be aware that the performance of this antenna will not be anywhere near as good if you use the ATU in your radio at the end of a coax run. This is because the coax becomes part of the antenna and the radiation pattern is all but destroyed. You will be extremely disappointed if you use the antenna in this fashion. The ATU must be at the end of the wire and connected directly to ground and the radials to get the performance that I have experienced.
Finally, if you have an Icom IC-705 and AH-705 remote auto ATU you can use the AH-705 ATU in place of the CG3000, you will get the same results as I have with the CG3000.
I have used my AH-705/IC-705 combo quite a few times with this antenna with excellent results although, the big antenna can sometimes result in the receiver of the IC-705 getting overloaded especially on the lower bands. This is easily resolved by reducing the RF Gain on the radio.
I spent the evening/early morning trying some FT8 on the 40m band taking advantage of the grey line and night time propagation. It’s been a while since I’ve stayed up late to catch some DX on 40m and it brought back memories of the all nighters I used to do when I was on air as F5VKM in France.
The 40m band has always been one of my favourites, there’s always great DX to be had when the band is open and on the grey line the world really is your oyster.
I’ve always been a huge fan of CW on 40m, there are some great seasoned op’s on the band and it’s always a real pleasure to QSO with them on the key. This time I decided to see what could be achieved with FT8 and 22w of power from my Yaesu FTDX10, a combination that should give me global reach.
Setting up at just past 6pm on May 9th 2022 the band was already busy with European stations, lots of them! There was no room to squeeze in and call CQ, the FT8 section of the band was packed with signals filling the allocation completely with many calling over the top of each other.
I decided to take my normal stance of search and pounce to get the stations I want to work rather than just working the masses endlessly.
I initially worked a bunch of Russian stations ranging from 1200 to 2200 miles out, good distances were easily achievable even though we were still in full daylight.
My home-brew multi-band vertical antenna worked well on 40m
In amongst the throng of FT8 stations I spotted UN3P, Vladimir in Karaganda Kazakhstan, not a country I have worked a lot since getting back on air and at 3013 miles it’s a good distance to achieve on 40m whilst still in broad daylight.
I gave a call to his CQ and he came straight back with an SNR report of -20dB, I sent him a report of -12dB so there was some 8dB difference between us. Considering I was only using 22w of power in broad daylight I was happy with the report. Of course I’ve no idea how much power he was using but, my signal was 6.63mW/Mile, not the lowest I ever had but, not the biggest either.
I worked a bunch more RA9/UB9 stations in the 2000-3000 mile range and then started hearing the Australian stations on the early grey line. Initially their signals were suffering some deep QSB but, it wasn’t long until their signals were constant and stable.
All the stations that heard M0AWS 09/05/22 – 10/05/22 on 40m
Ian, VK3VDX in Victoria was the first station from Oz in the log at -19dB/-20dB, pretty even SNR reports. At 10451 miles it equates to 2.10mW/Mile.
Closely following was John, VK5PO in Mallala South Australia, much stronger signals this time at -10dB/-14dB, 2.19mW/mile over a total distance of 10028 miles.
VK5PO Mallala South Australia
As darkness replaced light the propagation swung west with east coast USA and Canadian stations dropping in to the East coast of the U.K.
John, VO1BE was the first north American station in the log with -1dB/+1dB SNR reports. To be +1dB in Canada with just 22w really is quite impressive. I’m guessing he has a very low background noise level.
I worked a bunch of East Coast USA stations and then PY2GZ popped up on the waterfall. From my QTH I have a clear view South East to South West across flat ground for miles and so it’s normally pretty easy to work stations in that zone and this evening was no different. First call was answered and -10dB/-17dB SNR reports were exchanged, 3.68mW/mile over 5965 miles.
My 14.81m tall home brew vertical works superbly on the 40m band with tuning handled by my CG3000 Remote Auto Tuner. This is actually my 30m band EFHW vertical antenna but, removing the 49:1 Unun and replacing it with the CG3000 has made this antenna much more versatile.
CG3000 Remote Auto Tuner connected to the 14.81m vertical antenna and ground system
The next station in the log was BG0BBB in Xinjiang China with -9dB/-18dB SNR reports exchanged. China is always a hard location for me to get into for some reason so, I was glad to get another Chinese HAM into the log.
BG0BBB Xinjiang China
As the propagation started to swing westerly I got 8P4JP in Bridgetown Barbados into the log. It took a few calls to get the exchange completed due to very deep QSB between us but, with some perseverance the contact was completed successfully and I had a new one in the log!
I continued to work a flurry of East Coast USA, Brazilian and Puerto Ricon stations one after the other until suddenly stations from the east started coming in again.
First from the east was Igor, 4L1FL from Tbilisi Georgia, another new one for me that somehow seems to escape me every time I come across Georgian stations on the bands.
4L1FL Tbilisi Georgia
UN7JO in Ust-Kamenogorsk Kazakhstan was loud with me at -5dB SNR although I only got -21dB SNR back, some 16dB difference across the path of 3386 Miles.
One station of particular interest was VY0MEL, Julien in Rankin Inlet, Nunavut Northern Canada. This is the most northern Canadian station I’ve worked in a long time and it was great to get him in the log. His QRZ page is worth a read, he works at a mine in Nunavut on a 14 day rotation and so has a fair bit of time for HAM radio. Using just a dipole that is strung between two shipping containers and only 60cm above the snow in the centre he was a good signal at -19dB here in the U.K, especially considering he was still in broad daylight.
VY0MEL Rankin Inlet, Nunavut Northern Canada
Needless to say I had a fun filled evening/early morning on the 40m band, once again it didn’t disappoint and I got a couple of new countries in the log. I think the next late night will have to be a CW evening on 40m to see how well I do in comparison.
The full list of stations worked over 9th-10th May 2022 using FT8 on the 40m band can be viewed in my WSJT-X log in glorious technicolour with distances and mW/mile figures for every contact.
Map showing all FT4/FT8 stations worked up to 10/05/22 all bands
I spent some time this morning in the garden with the Icom IC-705/AH-705 combo connected to my End Fed Half Wave (EFHW) vertical for the 30m band. This is a great antenna that works superbly on the 30m band. Being a resonant half wave fed via a 49:1 Unun it doesn’t require any ATU inline normally and so it’s quick and easy to use with any radio.
Today I decided to disconnect and remove the 49:1 Unun and hook up the Icom AH-705 instead. I thought it would be an interesting exercise to see how well it handled the EFHW vertical on both 30m and the other bands.
Icom AH-705 connected to the 30m Band EFHW Vertical Antenna
I purchased a couple of 5m leads for the AH-705 so that I could setup the radio on the picnic table in the garden and be a comfortable distance from the antenna. They worked great and allow me to use the radio in the spring/summer sun with ease.
Icom IC-705 setup on the picnic table in the garden
The little AH-705 remote auto ATU really does work well with the IC-705. Each time you change bands all you have to do is give a quick press of the PTT on the mic and it automagically goes into tune mode and matches the antenna to the 50 Ohm radio in seconds.
I was was really pleased to see that the AH-705 ATU matched the EFHW Vertical for 30m on the 80m, 60m, 40m, 30m and 20m bands with a perfect 1:1 SWR. With the antenna consisting of 14.81m of wire this makes it somewhat short of a 1/4 wave on the 80m band and I’m not too sure how well it will work. On the 40m band it is a 3/8 wave antenna so should work well. It’s a 1/4 wave on the 60m band and of course a half wave on 30m band as per it’s original design. On the 20m band it is just under 3/4 wavelength long so hopefully should work reasonably well. Of course it won’t be as good as my 20m band EFHW Vertical that has a much lower angle of radiation but, will make an interesting comparison.
The antenna also tunes up nicely on all the other higher bands including the WARC bands. On 17m it is getting close to a full wave length and on 15m it is just over a full wavelength and so should work fairly well on these two bands albeit with a higher than optimal angle of maximum radiation.
On the 12m band it is 1.25 wavelengths long and of course on the 10m band it is almost 1.5 wavelengths long. I’m not sure how well it is going to work on these two higher bands but, for a 14.81m long piece of wire it certainly gives me a good chance on a wide spectrum of frequencies.
30m Band EFHW Vertical Antenna in the breeze
The bands weren’t in particularly good shape this morning but, I found some SSB signals on the 20m band and so decided to see if I could make some contacts.
First contact was with S51DX in Slovenia. He was using 1kw into a 5 element beam pointed pretty much directly at me. The little IC-705 S meter took a pounding with him peaking +30db over S9 most of the time. I was really pleased to get a 5/9 report from him using just 5w from the IC-705 on the standard 7v battery. Of course his station was doing all the work but, it’s good to take advantage of these big stations when running QRP power levels.
Next I had a QSO with John, EA7JUR in Almeria Spain. But this time the battery on the IC-705 was pretty much exhausted and so I hooked it up to the 12v supply to get it charging whilst I was on air. This of course gave me the ability to increase my O/P power by 100% to a massive 10w!
I wasn’t so strong at John’s end, only getting 5/5 report at best whilst he was 5/5-5/9 with me with some QSB. John was using a mini beam antenna again pointed towards me so once again all the work was being done at his end. We had a good chat for a number of minutes until it was time for lunch.
Listening on the 40m band I did hear a very interesting station, KN6IPA/Aeronautical-Mobile. Justin, KN6IPA is part of the crew on a USAF KC135 air-to-air refuelling tanker that flies out of RAF Lakenheath in the U.K. He was transmitting from the aircraft whilst in flight over Germany. His signal was between 5/9 and 5/9+20dB on my vertical antenna and had a massive pileup of people calling him from all over Europe.
I did try calling him with my punchy 10w of power but, couldn’t compete with the huge pileup of very loud, powerful stations all incessantly calling. It was really interesting to just sit back and listen to Justin’s information. He was using 300w into a wire antenna that runs from the fuselage to the vertical stabiliser. Of course being so high up he had a massive advantage and could be heard for hundreds of miles with ease, hence every one and their dog was calling him.
Photo of the KC135 tanker that KN6IPA was transmitting from courtesy of his QRZ.COM page
If you look closely at the photo above of the KC135 that Justin is a crew member on you can just make out the wire antenna on the vertical stabiliser.
I have to admit that I would love to spend a few hours on the radio aboard the KC135 whilst it was flying around, just imagine the DX you could work!
“Why don’t you mount your 20m EFHW Vertical antenna higher up in the air? It’ll work much better the higher you get it”.
I have over the years tried raising and lowering my vertical antennas for DXing and found that keeping the base of the antenna and feed point low has advantages over a raised installation. I’ll try and explain this using some 3D and 2D far field plots from the EzNEC antenna modelling software that I use.
Below are the 3D and 2D far field plots as I have it setup at the moment. The 49:1 Unun is at ground level with the base of the antenna also at ground level.
20m EFHW vertical fed at ground level 3D Plot20m EFHW vertical fed at ground level 2D Plot
Forgetting about the dBi gain figures for the time being and just concentrating on the overall radiation pattern you can see that with the antenna fed at ground level it has a typical circular radiation pattern with a deep null in the centre and a very low angle of maximum radiation. This makes the antenna perfect for DXing and is backed up by the success I’ve had on the 20m band working Australia, Thailand, Indonesia, South America, West Coast USA and Canada. This is exactly what I wanted and I’m extremely happy with it’s performance. I must add that I’m not looking to work European stations with this antenna, I’m only looking for DX stations especially those with very weak signals.
So now let’s take a look at what happens to the radiation pattern when we raise the antenna and the feed point above ground level.
First let’s raise the antenna so that the base and feed point are 3m above ground level.
20m EFHW Vertical with base and feed point 3m above ground 3D Far Field Plot20m EFHW Vertical with base and feed point 3m above ground 2D Far Field Plot
Looking at the two far field plots above you can see that with the antenna and feed point raised by 3m we start to get some high angle lobes appearing in the centre of the radiation pattern. The overall maximum radiation is still at a low angle and so this would still be good for DXing but, does have an element of high angle radiation to it now. This will of course mean we’ll start to be able to work stations much closer to us and also be able to hear them better.
Raising the base of the antenna and feed point to 5m above the ground we see that the high angle lobes get even bigger and start to distort the overall radiation pattern of the antenna.
20m EFHW Vertical with base and feed point 5m above ground 3D Far Field Plot20m EFHW Vertical with base and feed point 5m above ground 2D Far Field Plot
At 5m above ground the two high angle lobes have increased considerably which will result in more high angle radiation from the antenna. Maximum radiation is still at a low level though and so DXing will still be good with this setup but, from experimentation and experience I know that there are times when closer stations start to affect the ability to pick out the weaker DX stations. This is exactly what I don’t want.
Raising the antenna up even further to 10m above ground we get the following result.
20m EFHW Vertical with base and feed point 10m above ground 3D Far Field Plot20m EFHW Vertical with base and feed point 10m above ground 2D Far Field Plot
At 10m above the ground the two high angle lobes shown on the 2D elevation far field plot are now almost as big as the main lobe below it. This means there will be considerable high angle radiation from the antenna which will result in the ability to communicate with stations much closer to your QTH rather than focusing just on the DX stations.
If you’re looking for the best of both worlds then getting your antenna up higher is the way to go, you’ll be able to work stations in the 300-1500 miles range with ease and the DX stations thousands of miles away.
From my experience there is one disadvantage with this in that the closer stations tend to drown out the weaker DX stations reducing the overall DX capability of the antenna and this is why I keep the antenna feed point at ground level. From experimentation and experience gained over the years I’ve found that keeping the antenna base and feed point at ground level gives me a better chance at working the DX than I have if I raise the antenna up higher.
As with everything in life there’s always a compromise!
So it really does depend what you want to use your antenna for. If like me you only want to chase those rare DX stations that are always difficult to get then keep the base of the antenna and feed point low. This will maximise the null in the centre of the radiation pattern and keep interference from “local” stations to a minimum. The draw back to this of course is that you won’t be able to work the closer stations when there is no DX around.
However, if you want the ability to work more “local” stations and the stronger DX stations raise your antenna and feed point up to a more suitable level above ground so that you obtain more high angle radiation from your vertical antenna. Then when there’s no DX around you’ll still be able to chat with the more local stations.
I hope this helps all the people that read my blog understand the choice I have made and why I keep the base of the antenna and feed point at ground level.
When I lived in France (F5VKM) I was totally focused on the low bands. I spent years trying to get the Falkland Islands on 160m. Now living in the UK with a typical small garden I no longer have the luxury of big antennas. Currently I’ve just got my EFHW Vertical for 20m at the end of the garden.
Today I heard the Falkland Islands on 20m for the first time since setting up the new station, I was amazed to say the least.
WSJT-X FT8 working VP8VK with just 25w
I decided to give the two stations a call, didn’t get an answer from VP8ADR but, VP8VK then popped up and I snuck in and got a quick QSO with just 25w.
FT8 QSO with VP8VK
Working DX is so much easier on 20m than it is on 160m, I’m amazed!
-23dB is very close to the limit for FT8 but, it was enough to get a complete QSO and the Falklands in the log.
I also got VK6AS on 20m FT8 today, again with just 25w. This EFHW Vertical for 20m really is an excellent DX antenna, it’s perfect for the small garden too!
I completed the fine tuning of the 20m EFHW Vertical today, I got the SWR down to 1:1 at 14.10 Mhz. This gives me a perfect match for the CW and digital section of the band with the SSB part of the band not exceeding 1.4:1 at 14.350.
I ended up removing 34.5cm of wire from the original antenna length to get the resonance where I wanted it. This was caused mainly by the extra inductance added into the circuit by the 49:1 Unun. This is to be expected and perfectly normal when feeding an antenna via an impedance matching transformer.
I bolted the 49:1 Unun directly to the earth rod, this way it’s got a solid earth connected directly to it to keep the resistance to a minimum. (The metal mounting plate is also the earth termination point).
49:1 Unun mounted on earth rod directly
I spent some time today chasing the DX on the 20m band using the FT8 digital mode.
The fun started with VK2LAW in Sydney Australia, followed by E25ETT in Thailand, KP4CAR in Puerto Rico, 9G5AR in Accra Ghana and The Sahrawi Amateur Radio Club station S01WS in Western Sahara. A nice mix of stations dotted around the world.
PSKReporter map showing all the stations that I heard on 20m today
I like to keep an eye on the PSKReporter site whilst on air to see what I’m hearing. As you can see I heard stations from the West Coast USA right across to New South Wales in Australia and down south as far as Brazil. The 20m EFHW Vertical antenna and Yaesu FTDX10 radio combination really does have good ears
As for being heard, well it’s a similar story, below is a map showing all the stations that heard me as reported on the PSKReporter website.
Stations that heard M0AWS on 20m FT8
One again, great global coverage from the antenna and transceiver combo with only 20w being used for most contacts. (25w used to break some of the pileups!)
Overall I’m really pleased with the performance of the antenna, for such a simple design it works exceedingly well. One huge advantage of a half wave over a quarter wave antenna is that the point of max current is 50% along the antenna’s length, on the 20m band EFHW Vertical this puts it some 5m above the ground lowering the angle of take off and making it a great DX antenna.
If you’ve not got a lot of space but, want to work the DX on 20m then I highly recommend you give one a try, I’m sure you’ll be amazed at how well it performs.
Can’t wait to get a 40m EFHW Inverted L up next!
Information as to why it’s best to keep the feed point at ground level for this antenna is here.
My 49:1 Unun arrived from UK Antennas today, lost no time getting it into the garden and connected to the 20m EFHW Vertical antenna.
49:1 Unun from UK Antennas
I’m really pleased with the 49:1 Unun, really nicely put together and packaged professionally, great to get such a nice British made product!
Connecting the Unun up to the antenna I found that it added a little extra inductance I hadn’t planned for and so I needed to shorten the vertical wire a little to compensate.
Tuning the 20m EFHW Vertical
It took 3 snips of wire to get the antenna resonant in the 20m band again, with an SWR of 1.3:1 and the sun starting to set I decided that was fine for now and I’ll fine tune it tomorrow in the daylight. (See end of article for update)
Heading into the shack the 20m band was buzzing, lots of big signals and DX. I switched on to the 10m band and checked the SWR there, 1:1 across most of the band, perfect!
I then went on to check the 15m band, now I wasn’t expecting a match as it shouldn’t resonate there but, I found a 2:1 SWR across the band, weird!
So back on 20m, I plugged in the MacBook Pro and started WSJT-X in FT8 mode to see what was around.
20m EFHW Vertical at the end of the garden
First contact was into Canada, VE2FVV with a -10 report both ways and 2962 miles, not bad for 20w.
I then worked a flurry of stations from the USA but, the one I was really pleased with was PP1WW in Brazil. 5610 Miles using just 20w, this EFHW vertical really does has a lovely low angle of radiation.
PP1WW was the last station worked as it was dark by this time and the band closed. It was interesting to watch the PSKReporter site to see where I was being heard.
Stations that heard M0AWs on 20m
As you can see from the PSKReporter screenshot above, I was heard pretty much all over the world. I saw a number of VK stations in Australia pop up on FT8 but, never managed to get an answer back from any of them even though they reported hearing me on the PSKReporter site.
I was also pleased with the number of stations that I heard, once again good global coverage.
Stations heard by M0AWS on 20m
Band conditions are generally poor at the moment and we’re in a bad part of the 11 year sunspot cycle. Hopefully in the coming years propagation will improve and we’ll be able to work the world on just a couple of milliwatts!
I also tuned up onto the 10m band and heard quite a few FT8 stations on there, I was surprised as I wasn’t expecting the band to be open.
So tomorrow, I need to fine tune the antenna for the 20m band and get the SWR down to 1:1, hopefully this won’t affect the 10m band tuning too much.
Once the 12m Spiderpoles are back in stock I’ll get one ordered and build the 40m EFHW Inverted L that I’ve designed, I’m hoping it will open up the 40m/20/15/10m bands for some DXing over the summer months.
UPDATE: I ended up snipping off a total of 34.5cm of wire to get the SWR 1:1 at 14.100Mhz. This makes the entire 20m band useable with the SWR less than 1.5:1 at each end of the band. 2nd contact after trimming the wire was VK2LAW at 10454 Miles using just 25w of power.
Information as to why it’s best to keep the feed point at ground level for this antenna is here.
More soon …
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.Ok
