Which HF Antenna Should I Get?

Don't worry!  This is not going to be a post about whether a 3 element yagi is better than a hexbeam or some typical drivel.

In fact, it's a headline aimed at getting some search engine hits so that beginners can read this, a second update, celebrating my first complete year of relatively casual operating, showing just how much can be achieved without splashing-out on expensive ham equipment. 

Regular readers may recall I bought my first rig off E-Bay, costing me a modest £270 for a very nicely kept Kenwood TS-50 that is still fully functional.  I've since bought a TS-480SAT.

£270 got me this excellent rig to start off my ham career.  It's still working strong.

 
My first antenna for about two months was just a long piece of copper wire strung from the ATU's 'wire' output, out through the wall, up 5m and then sloping down to the bottom of one corner of our garden - about 23 metres of wire, chosen for no particular reason.

I could only run 50W out of that antenna due to the difficulty in matching it due to wild impedance changes.  On a few occasions, I got some hefty RF burns to my PTT finger, but they weren't things that hurt for any more than a minute or two!


Despite all this, I still got out daily to the Caribbean, the US, all of Europe and even once into VK.   A very poor antenna system, but the thrill of making it to VK-land with that wire is an excitement that was very much relished!

Can't do real DX with simple equipment?  Rubbish!  An indicative map of my first year's operating with 100W SSB and a delta loop antenna.

 
Big guns will say 'yeah, but your signal was rubbish!'.  Well, not that bad, as I hit the back of the VK's beam at the time!  And it misses - completely - the raw excitement of making that far-off contact when you've never done if before.  Filling you logbook every time you press a button is, perhaps, not quite so satisfying.

Since then, I discovered the joy of delta loops - and loops in general.  I use full wave loops in various shapes from 20m HF operating to 70cm satellite downlink, and they are very easy-to-match antennas.  I can't see that I will be moving to anything else any time soon, although my elevated, sloping ground and rural location does maximise the performance.

What were the highlights of the 2011-2012 operating year for me?  Often, they were not long-haul DX, although getting into Antarctica was certainly an exception!  After all, the bloke on the other end doesn't think he is very exciting for being where he is.  He's just 'there', whilst I am 'here'.

No, the memorable ones are made special for their humanity and for transporting my imagination to another place.  A man talking to me yesterday on 10m through his 5W handheld into the KQ2H repeater in New York, out with his dog in Central Park. 

I painted much the same mental image when I had a QSO with a VK/mobile station.

Then there was the VK mobile station, where I could clearly hear the dusty road and engine noise as he thundered across the vast Australian outback to his home, about 2 days distant.

A maritime mobile station in port in Brazil - and hearing the same OM off Sierra Leone and then Australia.

An elderly, wheelchair-bound man in Ukraine, saying he never saw anyone and wouldn't know what to do with himself if it were not for amateur radio.  I often think about that man.

A contact on an otherwise-empty 15m band with a Peruvian station, special as it's where my eldest daughter lives.

Finally, a Spanish station honking his horn, saying, "You see?  Real mobile, eh?"

Cheers!  How HK3C imagined me!

They all made me smile, as did the esteemed HK3C - John Bartlett's exchange with me just before last Christmas, when he created in his mind a picture of me sitting with velvet slippers and a dressing gown as I sipped some Ruby Port at the operating chair!   Not far off, John.  Not far off at all...


So, all I will say to those, like me, who have held back from either getting into transmitting, or becoming an operator at all, is: get hold of a delta loop!  I do keep banging-on about this, but there are very good reasons why.  Here they are again:

(1) Cheap.  You can make one out of any junk wire, and so long as you can use a tape measure and cut some wire (about my level of expertise last year), you can't realistically go wrong. You can even buy a delta for a price less than the wire and a good balun if you don't want to homebrew.

(2) Forgiving.  My 20m loop was 1.5m too long for many months.  It still allowed me to operate the world on SSB, even though the effectiveness of the antenna was clearly compromised to a considerable degree. I only kept it at that length because it was working pretty well and adjusting things tends to cause headaches.  It now sings perfectly on 20m after a few hours of careful adjustment.

(3) In all but the worst environmental conditions (powerline clutter, very hemmed-in situations, etc), delta loop wire lengths are very good at conforming to theoretical predictions.  Use the variety of online calculators and cross-check their output (be sure they are actually different sources, too!) rather than books, as I've found a lot of errors on wire lengths, often ones which have been repeated for years, in many of those!

(4) Simple to erect.  You need just one fishing pole to get a delta for the 20m - 6m bands up into the air, with a base height of about 1.5-2m.  This makes it good for rapid, stealthy deployment.  If you have trees, a delta becomes essentially invisible.  Getting a dipole to 10m, if you have no trees or existing supports, is very much harder and more visible.

(5) You can feed with either a 4:1 balun and 50 Ohm coax at the antenna, or with twin feed to an ATU's internal 4:1.  I suggest you use good quality 4:1 external baluns, such as those made by hand by G-Whip.

(6) An excellent low-angle radiator.  On the excellent mineralised ground here, the peak gain is at 12-15 degrees and essentially the same value - about 2.05dBi - as that of a dipole (typically 2.15dBi), but with an omnidirectional pattern that falls only by about 2dB in the worst direction (in the plane of the antenna wire).

(7) Makes an excellent, easy-to-deploy portable antenna.

So, ignore the adverts, the wildly over-optimistic adverts about no radials and true aircraft alloys.  Just get some wire and start making your own antennas.  Then, start talking to the world!

Happy Christmas for 2012, and have a Great 2013!

Wire Length for 20m Delta Loops

An update on the delta loop is overdue.  I love these antennas.  They turned amateur radio from a noisy, poor signal sort of hobby into one where I could enjoy global DX for essentially no cost.

I've had my moans about how difficult it is to find reliable information on getting a delta to resonance, and I still don't understand why so many different views, because deltas are not especially sensitive to their environment.

Sometimes, you just have to use one of these.  Just not too much!

Anyhow, I decided to go out and do a proper job of getting my delta to sing properly today.  No wind, and a warmish winter day helped.  I disconnected the coax, attached an SWR meter to my old TS-50 running on a car battery, and then hooked up with a short piece of coax to the 4:1.  The whole set-up, radio and all, remember, was outside, working at the antenna itself, with no more than about 1.5m of coax in the connections.

As it was, I knew the antenna was too long.  This was because I stupidly tried, being a bit green behind the ears a year ago, to tune the antenna using the ATU.  This is a very dumb idea for two reasons: meters on ATUs seem not to be so good on cheaper models, and measuring the SWR at the transceiver, rather than antenna end makes the SWR look better than it is because of losses in the coax.

So, a year wiser, I sent a signal into the delta.  The meter read 3:1 at the upper end of 20m, 2.5:1 at the lower end: the loop was, as I knew, too long.  Although it's obvious what I had to do next, you always have that feeling that, when you chop wire, at some point, you'll end up regretting it.  Antennas don't play ball and slowly drop to a good SWR like they're meant to.  They often stop at some value well short of 1:1, and then start climbing.

After a good old chop that brought me back to a piece of tape on the wire I'd marked the theoretically-correct length a year ago - 21.3m - I found the SWR was beginning to bottom-out at 1.6 to 1.7:1.  That's good enough for me, and I expect it would not go much lower, if any with further chops, especially as the 4:1 balun almost certainly brings the system impedance down below 50 Ohms.

Coming back indoors, I found the match at the transceiver end almost perfect, needing no ATU to work 20m and with a near-full 100W going out.

Job done.  I hope!

Delta Loop in the Wind!

Over the past year, I've been exposing my fishing-pole supported delta loop for 20m to increasingly harsh conditions.

Whilst putting the pole up and down is very easy, taking only a minute, it is a bit of a hassle, especially as in the UK, winds tend to blow up, die down, and blow up again over the course of a day.  Constant retraction in the face of high winds is therefore not really ideal.


video-2012-11-02-13-16-48 from John Rowlands on Vimeo.

My pole has never slipped under load.  Slippage happens when the pole is exposed to winds from another direction, because they've already been loosened, and so fall down.  The trick is to stop the sections slipping, which most people do with tape.  This is OK, but it does damage the protective lacquer on the pole, which does have a certain degree of weather protecting quality to it.

Now I use jubilee clips (hose clamps) with butterfly nuts at the bottom of each section.  I got mine in the UK from FEP Hydraulics.  This seems to work very well, in that my antenna has now lived through several strong gales (up to 55mph) from the west and east, with no slippage.

SteppIR vs. Delta Loop - Who's The Best?

It's been windy again this week.  But I'm getting more confident in my fishing pole-and-wire 20m delta loop's ability to put up with hurricane-force winds (a term I use accurately - we have 120km/h or more regularly throughout the winter - and sometimes the summer!)

A wire triangle can't possibly be as good as a beam running power, right?  Wrong!

So, I switched on to find an US east-coast station coming in at a nice 58 or so.  He had a straightforward three element tribander on top of a house chimney, running 600W.

One of my colleagues down in Swansea, meanwhile, called said US station.  He was reported as received at 55.  He was running a three (I think!) element SteppIR antenna, with 400W going out from 40 feet.  Most of us would agree that's a big investment and an excellent set up.  What it doesn't tell you about is the antenna's environment.  Swansea is a highly-developed, urban environment.  My QTH isn't.

A big, expensive antenna does not automatically buy the best signal.

So, I fired a call across to the same US station.  Remember: my antenna is a pocket-money one element delta loop held aloft by a 10m fishing pole with the top 2m removed to allow weight to be carried at the tip.  I was running 100W, probably more like 90W after losses.

Who do you think had the best signal?

Well, it was neck-and-neck: the multi-thousand dollar SteppIR, amp and tower set up was getting the same report as my pocket money delta!

I wouldn't be so stupid as to claim my set up would win in every comparison with the more expensive system, but you do have to accept that bigger, more expensive and more powerful does not automatically mean a better received signal.

Environment is important, perhaps more so than many will accept.  Think about it.  If you want good low angle departure angles for long-haul DX, you need a horizon that is so clear of obstructions that very few living in countries like the UK will ever have that luxury.  Few live within sight of the sea.  Or have high concentrations of metals in the ground beneath their antennas.  We have all of these things, which makes a big difference to how well a simple station can get out.

So before you spend the bucks.  Try simple, proven antennas, especially verticals (which includes vertical dipoles, of course), to see just how far and how well you can reach...