Since being licenced, I have always run modest HF antennas at my home QTH. I was restricted in physical space at my previous home and at the new location I have more space for slightly larger antennas, but decided to keep the setup stealthy to reduce the risk of complaints from neighbours.
Antennas at my QTH, Western HF-10 (HF), Diamond X50N (V/UHF).
I have always tried to have 2 antennas installed at any one time; a horizontal and a vertical. I have had great successes with horizontal antennas, the Alpha Delta DXCC, G3TPW Cobwebb and my current horizontal Antenna, the Western HF-10 have performed very well indeed with no issues mechanically. The Western has been a loyal servant to me since moving into this house. On 80/40/20m especially, I cannot rate it highly enough.
Whilst the aforementioned antennas have been excellent and remained in service at the station for some considerable time, I have always struggled to find a vertical I have been happy with. Why have a vertical? Well propagation is one reason; often signals are stronger when switching between a horizontal and vertical. Also, I think having a spare antenna is great if you want a bit of redundancy from a damaged antenna or feeder. Lastly, FM repeaters on 10m and 6m will be horizontally polarised, as will FM simplex contacts as a rule of thumb. So a vertical of some description is worthwhile.
Most verticals I have tried have been rather short in size which has a performance issue from the outset. There are larger verticals on the market, a few of which I have tried but they have always disappointed as they have either required significant wire radials to perform or they are so long they need guying which is both ugly and impractical for my station. In most cases they are expensive.
Then, recently I read a book “How to listen to the world” by Ken Reitz KS4ZR. An excellent read, aimed mainly at people new to ham radio and shortwave listening but there is a lot of interesting information in there, especially regarding broadcast AM and receiver equipment which would interest the OMs as well.
2” Aluminium mast mounting
In Ken’s book he recalls not being ready for field day and as the start time loomed, improvising an antenna by hooking his ladder to his ATU and it ended up working rather well! This got me thinking about my vertical issue and I have found getting lots of metal in the air certainly is an advantage with a vertical but it then gets into all sorts of difficulty as mentioned – swinging in the wind and ready to snap as soon as a heavy gust of wind hits it. That or we guy the antenna, creating cheese wire type hazards all over the garden.
That’s when I thought, I wonder if the mast that has played host to several lacklustre vertical antennas and currently just supports one end of my wire antenna would actually work as a HF antenna? Well, the cogs started turning and after some thought, I decided I would try.
Soon after the build began. In addition to the mast itself, I would use a 9:1 UnUn and an earth spike in the ground to create the antenna. I assembled the antenna with the radiating side of the UnUn connected to the mast via a short length of flexweave, attached to the mast by nut and bolt and washer, all waterproofed with silicone sealant. I also waterproofed the connections to the UnUn by wrapping the entire thing in self-amalgamating tape.
My masts I use now are a slot together affair but that was just for ease of shipping, I have also had a single length of pole in the past which would logically make no difference when using as an antenna. The 2” diameter aluminium pole is supported by 2 galvanised standoff brackets, attached to my garage-come-shack. This particular mast has a length of 9m in height and is mounted about 1 meter off the ground.
I set to work, building the simple antenna with a pre-built UnUn from my Pro Whip Antennas 10m portable antenna. I added 7 turns to the RG-213 feeder cable to act as an RF choke and once completed, I attached the other side of the feeder to my MFJ antenna analyser. No band showed a SWR of over 3.1:1 and most (including 160m were between 1:1 and 2:1).
Connections to the UnUn – flexweave to the mast and to the earth spike.
OK so we know just because the SWR looks great it doesn’t mean its going to be a particularly efficient antenna. However on something like the 20m band this near ½ wave antenna is particularly “hot” and when switching between this and my Western HF-10, there were occasions where the vertical did outperform it on receive. It “gets out” too. My first contact was on 14.290MHz with OH1TD 59 report; I was using 60 watts. Later that evening I worked SP8K and OE5XJN on 20m and SV7LNX/P on 40m using 100 watts who gave 59+5, 57 & 55 reports respectively.
One thing with verticals, they are generally more susceptible to atmospheric noise. This design is no exception. I found listening to the chaps on 1.933MHz rather difficult to hear on the vertical but the Western HF-10 received them better, mainly because of the reduced noise floor. The Western HF-10 is advertised as top band capable but I haven’t been able to get mine high enough or the ladder line vertical to allow for this. The solution is to use the vertical for transmitting and the Western for receive, achieved in my case by pressing the Ant A/B button on my LDG ATU when switching between TX and RX but could also be done with the A/B antenna switch on some radios, or using the RX antenna jack on others.
I am more relaxed when the wind is up now because, there is no weight being supported by the 2” aluminium pole other than the pole itself, so it would take an apocalypse type event or a strategically positioned lightning bolt to bring this antenna down. Additionally I have the accolade of being able to say I am using a homebrew antenna too, and it only took a few moments to build!
Photo showing Western HF-10 and Diamond X50N from other side.
So, next time you are looking for a simple HF vertical, and with bad weather a part of life for most of us on this turbulent planet, why not look up at what your VHF/UHF collinear or small HF compromise antenna is actually mounted on and ask yourself:
“Is the mount actually a better antenna than the antenna?”
Update 05/10/2014: I have now added 3 radials to the “earth” side of the UNUN, which seems to have helped with the noise a little and from casual observations seems to be bringing up in performance a little more.