Category Archives: Ham

How to be a Successful HF Dxer Part I

This is the first part of an article I wrote for the newsletter of the local amateur radio club which I used to be a member of. I resigned a few years ago when the club was effectively taken over by a training clique who were mainly interested in generating a revenue stream for the local scouts and not at all interested in dx.

This will be an irreverent and not too serious look at how to be a successful HF DXer. Well, what is DXing? For some people it’s working the local 2m/70cm repeater from the other side of town. For our purposes I’m going to define it as working ALL of the DXCC entities on as many different bands as possible in either ssb, cw or rtty.  (Sorry but we won’t be discussing psk31 here as it sends me to sleep…zzzzzz).

What’s a DXCC? Well, simply put it’s either a country or part of a country – the American ARRL keeps and approves the definitive list (at the present time there are 340 of the critters). The UK actually comprises seven DXCC, (England, Scotland, N Ireland, Wales, Isle of Man, Guernsey and Jersey). The USA is basically one DXCC (and so is China). If you want to find out the latest list of DXCC Google (as always) is your best friend, Joe.

So, let’s say that to be a successful DXer you need to work 340 DXCC entities; in ssb, cw and rtty on the following bands: 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m and 6m. Time to introduce a new concept – band slot. There are 340 (DXCC) x 3 (modes) x 10 (bands) bands slots to be worked – a total of 10,200 band slots! You will enter DXing nirvana if you have worked all 10,200 by the time you become a silent key – instead of 80 virgins awaiting you you’ll have top of the range Icom and Yaesu transceivers, stacked yagis on 100m towers and the sun spots will always be large and plentiful! But enough of that.

Our goal as DXers is to work as many of these band slots as possible. The first step should be to work the 340 DXCC entities on whatever bands and modes you can (actually the very first step is to work your first one hundred and take it from there!). By the way some people think you have to send off QSL cards to the States in order to be told how many DXCC you have worked. Nothing could be further from the truth – you know how many you have worked! Remember – this is a hobby and a certain bunch of our transatlantic cousins threw a lot of tea into Boston harbour to protest about King George having control of the DXCC list (or something like that). So nowadays you don’t need Obama to tell you who you have or haven’t worked!

There are quite a few ways to check you are in the dx log if you are bothered: use the ARRL Logbook of the World (LOTW) system, check dx station’s online log, check dx stations’s Clublog page or even just send the dx station an email! I’ve done all four in my time – LOTW is useful though it is a pain to get set-up and uses heavier security than on-line banking. Perfect example of an over-engineered system!

So how to get on the right road to DXing nirvana? Assuming that you have a radio and antenna what is the most important thing of all? Expensive radio, lots of antennas, morse key? Nope, the most important thing of all is switching the radio on and tuning around the bands. Because if you don’t do that you won’t be building up your total very quickly! So,to be a successful DXer switch on your radio at least once a day and tune around – your aim is to work a new band slot. Luigi and his Italian mates may be overrunning 40 and 20m, transmitting on top of the DX station but have you worked Italy itself on 12m? On 30m?

In the next article I’ll talk about how to optimise your working periods and build up those band slot totals!

CQ WW CW 2013 Map of QSOS

I had a play in last weekend’s major CQ WW CW contest – staying on 10m all the time. Goal was to work as many DXCC and CQ zones as I could. I ended up with 28 zones and 79 DXCC worked. The link below shows the QSOs graphically:

Gear was Icom 756ProII/Cushcraft MA5B mini-beam at 9m and Writelog software for rig control, cw decoding and keying.

Trapped Inverted L Antenna for 160/80/40

Here’s a simple antenna which will get you on the air on top band and 80m (40m as well at a pinch) in a small garden.

Following on from an article in Practical Wireless Feb 2004 by GM0ONX which showed how to build an 80/40 trapped inverted L antenna I modified the design to cover 160/80/40.  The traps are constructed from plastic tubing and regular 50 ohm coaxial cable. For the tubing use washing machine outlet pipes obtainable from any DIY store for a few pounds and cut to size using small hacksaw. Support the vertical section using a non-metallic extendable fishing rod. Here’s how to add top band in easy steps:

  1. First construct antenna as in original article but reduce length of 6.55m section to 5.55m and do not attach end insulator.
  2. Build a 21 turn trap following instructions in article. You can play around with trap design using the free program CoaxTrap from
  3. Attach 21 turn trap to end of 5.55m section and add another 9.3m of wire terminated with the insulator to other side of trap. Don’t solder wire connections on trap yet.
  4. Hoist antenna into air and check swr on 40, 80 and 160. 40 should not have changed from original design and should have minimum swr around 7.050.  Adjust, firstly, 5.55m wire to move minimum swr point on 80m where you want it. 80 is a large band so if you are into CW/RTTY aim for 3500-3600 while ssb is somewhere between 3.600 and 3.800 depending on whether you want to inter-G ragchew about arthritis (and every other ache and pain known to man) or go for DX. Secondly adjust length of 9.3m wire for top band. The dimensions I have given above in (3) give resonant points at 7.050, 3.750 and 1.940. Just adjust for your band of interest. Finally solder wires, waterproof traps and stick horizontal portion of antenna as high as possible.

The antenna works very well but swr bandwidth of <1.7:1 is around 40 kHz on top band but using an atu will give you all of band. II have worked almost 40 DXCC countries on top band (with contest in progress). You probably won’t work any continental DX on top band but the whole of Europe is very possible. You will be a VERY loud signal on the Sunday morning AM net! It also works very well on 80m but performance on 40m is pedestrian due to most of antenna being vertical and it will be 10-20dB down on a half-size G5RV mounted high and clear.

To get improved TX output you will need to add some radials to earth rod to improve signal strength on top band. This will make no difference to RX performance. The great thing with this design is that you get a working top band antenna into a horizontal space less than 20m long.

Here’s the original article from Feb 2004:

Download (PDF, 918KB)

GM0OMX published a follow-up article in January 2005 showing how to add top band to his design. However I came up with my design in the summer of 2004. Here’s the later article:

Download (PDF, 488KB)




Fun on 10m

TA MF has been very poor the last few days though some dxers have been getting some good results in the afternoons to Asia – see JF’s blog –

Here in London 10m has been quite open and I worked my 264 DXCC yesterday – FK8DD Sam in French New Caledonia –

Today I played around on 10m AM using my Icom 756 PROII to drive my Acom 1000 amplifier. Antenna was the 1/2 G5RV as stormy conditions in London meant I kept the Tennamast down so was not using the Cushcraft mini-beam MA5B. Had a nice QSO with VE3FGU in Keswick Ontario – The pint-size G5RV is not a bad performer on 10m (or 40m) though it is pretty poor on the other bands. The AM portion of the band is from 29.0 – 29.1 MHz.

Other DX worked on 28 MHz (10m band== 28 MHz) over the weekend included KG4HF with rtty in Guantanamo Bay and an ssb contact with JW9JKA Svalbard island.