My IC-705 and AH-705 arrived today from ML&S, I wasted no time getting it hooked up to an antenna and started working my way through the manual getting to know the menu system.
After a few hours tinkering I piped up on 20m SSB and worked a couple of stations with ease using 10w. No problems getting through and to my surprise got a 5/9 report from both stations.
Later in the evening I decided to give it a go on 20m FT8 using just 5w O/P using the battery on the back of the radio that was now fully charged. It’s interesting to note that I didn’t need any drivers on my MacBook Pro to use the CAT and Audio via USB on the IC-705. It was simply plug and go. Much easier than it was with the FTDX10.
There was a fair amount of DX about on 20m including a few stations from Australia and Japan. I never managed to get a response back from either but, PSKReporter was showing that I was heard!
PSKReporter showing M0AWS being heard by BG7BDB
I also noticed that a station in China was hearing me too. BG7BDB in LinXiang City reported hearing me at -17dB. I quickly hunted around the waterfall and found him and gave a call.
To my amazement he came straight back to me and we exchanged SNR reports, 73 and he was in the log.
WSJT-X FT8 contact with BG7BDB
Looking at my WSJT-X log the distance to BG7BDB is 5467 Miles, at 5w O/P that equates to 0.91mW/Mile!
FT8 really is an impressive mode, it allows QRP stations to work the DX that just wouldn’t be possible on SSB. I have to say I’m really impressed with the Icom IC-705. The receiver and filtering isn’t as good as my Yaesu FTDX10 but, it’s an impressive little package. Portable operations with this radio is going to be a lot of fun!
During the month of June 2022 U.K. radio HAMs will be able to use the “Q” regional secondary locator in their callsigns to celebrate Her Majesty the Queen’s Platinum Jubilee.
I now have my notice of variation (NOV) for my HAM Radio licence that will allow me to use the callsign of MQ0AWS throughout the month of June 2022.
I’ll be active on all HF bands using CW and FT4/8 mostly. I may do some SSB on 40/60m depending on how it goes.
I’m hoping many stations world wide will want to contact the GQ/MQ/2Q stations throughout the celebration period and that you’ll all be able to collect the 70 necessary callsigns and contacts to win an RSGB certificate.
I will be logging all contacts on EQSL.CC at the end of June 2022.
More information is available on the RSGB website.
I look forward to using the MQ callsign and hope to have many pileups on the bands!
“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.
Ever since I got my Class A HAM Radio licence I’ve always been fascinated by the low bands.
160m, 80m and 40m have been my favourite go to bands for chasing DX for many years and I’ve really enjoyed overcoming the challenges that come with such low frequency radio operations. Working DX on 160m I learnt a lot, having a good receiver and a quiet antenna are far more important than having a lot of power. The QRM/QRN on top band often masks the weak DX signals and so designing and building antennas that have a relatively low angle of radiation but, are super quiet on receive is a skill that all top band DXers should embrace.
It’s particularly hard to work DX on 160m in the summer months however, all those DX signals are still there, they’re just masked by the static crashes that plague top band throughout the warmer months.
Discovering the grey line was a real eye opener too. Getting up early in the morning to catch that magic moment that starts just before the sun rises to about an hour afterwards, with DX signals pouring in from VK/ZL before the D layer gets established again. Discovering that on the grey line signals from afar often arrive from a very high angle and can be heard much better on a large horizontal loop near the ground than a large vertical.
As you can tell, I’m passionate about the low bands but, now I’m back in the U.K. and have a U.K. sized garden again those days of large full wave antennas on the low bands are gone and so I must look to pastures new.
To this end I’m going to get onto the higher frequency bands, 20m and upwards. I must admit that I’ve hardly used these bands as I’ve always been so focused on the lower bands.
Currently I have delta loop for 30m up in the garden, this is a great band for us CW and digital guys, it’s a band I really enjoy and so will continue to use it whilst discovering the higher bands.
So I thought I’d start with the 20m band, it’s a band that I’ve heard is really easy to work DX on. Being much quieter than the low bands I’ll give the delta loop antennas a rest and venture into the land of vertical antennas again.
Doing some antenna modelling on EzNEC the End Fed Half Wave (EFHW) antenna has a great radiation pattern with a nice low angle of radiation and even some gain compared to a dipole.
Construction will be easy as the antenna is so small compared to the low band antennas I’ve built in the past.
20m Band EFHW Vertical Antenna
An EFHW antenna is a relatively simple affair and for 20m it’ll be somewhere around 10.25m tall depending on where on the band I resonate it.
The difficult thing about half wave or any multiple of half wave antenna is that they present a very high impedance at the feed point. Unlike a half wave dipole that is made up of two quarter wave legs that present an almost perfect match to 50 Ohm coax cable (or a 1:1 balun), the EFHW will have a much higher impedance, normally in the range of 2000 Ohms or more. Having such a high impedance also means high voltages at the ends, something to be very aware of especially if you have children or pets in the garden!
Matching to this type of antenna can be done two ways, a simple LC circuit for high impedance feed points or via a 49:1 Unun.
Since I’ve built 1:1 baluns in the past for my delta loop antennas I’ve decided to go the way of the 49:1 Unun.
Simple LC Circuit for High Z matching and a commercially manufactured LDG 49:1 Unun
Looking online for parts to build a 49:1 Unun I stumbled across UK Antennas, they seem to have a wide selection of pre-built EFHW solutions and some very nice looking 49:1 Ununs capable of handling 400w, much more than I will ever throw at it. Contacting Ian the owner of the company via Ebay I found he has a 49:1 Unun in stock that he can ship to me next day so I decided to go ahead and order one rather than source the parts and build it myself.
UK Antennas 49:1 Unun
With the Unun sorted, let’s take a look at the radiation pattern for an EFHW Vertical on the 20m band.
Since I’m looking to do mainly CW and digital modes I’ll be tuning it for the lower end of the band.
Modelling this on EzNEC I’m pleasantly surprised at the radiation pattern of such a simple vertical.
20m EFHW Vertical 3D Field Plot
To get a radiation pattern like this on the low bands requires a very large vertical, on 160m we’re talking 80m in height!
On 20m an EFHW is only around 10.25m long, very easy to put up in most U.K. sized gardens using nothing more than an extendable fibre glass pole. The 3D Field Plot shows the lovely deep null in the centre as you’d expect and a great low angle circular radiation pattern.
20m EFHW 2D Field Plot
The elevation 2D field plot really shows the beauty of this antenna.
5.62dBi at 10 Deg and 5.56dBi at 5 Deg, perfect for the long haul DX chaser. The wide deep null in the centre will help attenuate the signals arriving at high angles from the EU that plague us on the East Coast of the UK.
So, it’s time to go find some wire, get cutting and get a fibre glass extendable pole mounted in the garden ready for the arrival of the 49:1 Unun.
I’ve started thinking about antennas for the M0AWS QTH. Unfortunately we only have a typical U.K. sized garden now, which is tiny compared to the acres we had when we lived in France (F5VKM).
So, small gardens means small antennas.
The only direction I can go really is up, although most of my neighbours are very antenna unfriendly!
Like most radio amateurs in the U.K. I’m trying to find a single antenna that will give me the best performance possible on as many bands as possible.
Of course we all know there is no unicorn antenna that does it all but, with some compromise we can do fairly well on a mix of bands with a little consideration.
To this end I’ve been looking at Inverted L antennas. It’s not an antenna I have any real experience of but, it’s interesting to research.
40m End Fed Half Wave Inverted L
I started with a design for the 40m band. A simple end fed half wave inverted L antenna that consists of two parts. The vertical section is 11.95m high and the horizontal section is 8.7m long. Total length of wire is 20.65m. Modelling the antenna with 1.5mm wire it gives some surprising results.
3D Field Plot on 7.1Mhz2D Field Plot on 7.1Mhz
As shown in the two field plots above, the antenna has an extremely low angle of max radiation making it ideal for DXing. Gain at 10 Deg is 3.99dBi, not to be sneezed at. The 3D plot shows the overall radiation pattern to be almost perfectly circular.
On the 20m band the antenna presents a favourable pattern considering it’s a full wave length long.
The angel of radiation is somewhat higher than on 40m but, this is to be expected.
2D Field Plot on 14.1Mhz
On the 20m Band the antenna gives a gain of 7.07dBi at 25 Deg. A higher angle of radiation than on the 40m band but, still very usable. At 5 Deg there is 4.29dBi of gain which makes it ideal for DXing.
3D Field Plot on 14.1Mhz
On the 15m band the pattern isn’t as good as on 40m & 20m however, it would still be usable.
3D Field Plot on 21.1Mhz2D Field Plot on 21.1Mhz
With a gain of 6.04dBi at 25 Deg it should perform very well on the 15m band. At 10 Deg there is a gain of 1.12dBi. The overall pattern is a bit lopsided and it also has more high angle radiation than I really want but, like all multi band antennas there’s always a compromise.
Next I modelled the antenna on the 10m band, the 3D pattern is rather alarming but, it has potential.
3D Field Plot on 28.1Mhz
There’s a lot of high angle on the 10m band and a somewhat out of balance pattern but, there’s also gain to be had at a lower angle too.
2D Field Plot on 28.1Mhz
The main gain is 6.37dBi at 45 Deg, ideal for short hop communications however, there is 3.58dBi of gain to be had at 10 Deg, much better for DXing.
It’s not ideal for 10m by any means but, when you take into account that the antenna is 2 wave lengths long it’s hardly surprising.
I’ve still got a lot more work to do on this modelling but, it has huge potential.
I’ve not even started thinking about impedance matching yet, I know it’s going to be a monster and nowhere near 50 Ohms but, I’m sure a simple LC network will do magic with matching it to the transceiver.
More soon …
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