DXCC on 17m using FT8 – Fifty entities worked so far

My challenge to work DXCC on 17m using FT8 is coming along nicely – I’ve now worked fifty separate entities as follows.


Although I’m not going to go out of my way to get them confirmed because Logbook of The World and the DXCC award system doesn’t differentiate between different data modes, it’s good to see that 43 out of these 50 have already confirmed via LoTW.

It’s already starting to get difficult to find new countries to work and I know things will only get more tricky, especially considering the state of the bands.  It doesn’t matter though because I’ve not set any time limit so I will complete this challenge.  If you’re in a country that I’ve not worked yet and would like to help me out, please contact me and perhaps we can arrange a sked.

Posted in Amateur radio, Data, DXCC-17m-FT8, FT8, HF | Tagged , , | Leave a comment

SCC RTTY Championship 2017 – The results

Back in September I put an entry in to the SCC RTTY Championship and I’m happy to report that the results are out and can be seen in full here.

I entered the single operator 15m section and I’m pleased to report that out of the fifteen entries, I was first.

I logged 190 QSOs but only 184 are shown as valid in the chart below – This is because six of them were duplicates where people called me more than once.  This is something I have no control over and I prefer to work duplicates than waste time telling people it’s a dupe.  This contest was a good example of that, one station called me four times and checking the UBN reports afterwards, only one of those had my callsign correct.

There’s a nice comment on the “Final Comments” section regarding my entry:

“We are happy to have Keith G6NHU back in contesting again and he immediately won 15m band with a very clear log (184 QSO without error)- congrats OM.”

I did enjoy this contest, even though it was slow going.  It was good practise and I’m happy with the result.

SCC RTTY 2017 Championship 15m results

SCC RTTY 2017 Championship 15m results

 

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Increasing transmitter output power – What effect does it really have?

Power is always an emotive subject so I thought it would be interesting to review transmitter power levels and see what difference increasing power makes to your signal.

To start with we need to look at how signals strength is measured. In 1981 the IARU Technical Recommendation R.1 was that S9 on the HF bands is a receiver input power of -73 dBm which equates to 50 uV at the antenna input assuming the input impedance is 50 ohms. It also suggests that there should be a diffence of 6dB per S point.

Let’s assume you’re running 10 Watts output power (the limit for UK Foundation licence holders) and the station you’re working gives you an S5 report.

If you increase your power to 20 Watts, your signal strength will now be S5.5 because each time you double your output power, you’re increasing it by 3dB – As already said above, one S point is equal to 6dB difference in signal.

Double your power again to 40 Watts and your signal strength will now be S6.

If you then increase power from 40 Watts to 50 Watts (the limit for UK Intermediate licence holders), that’s just another 0.9dB gain which is less than one third of one half of an S point. In reality, it probably won’t even be noticed.

Let’s start this at 50 Watts. Again, your 50W transmitted signal is being reported by the other station at S5.

You double your power to 100W which is a 3dB increase and will give you an S5.5 report.

Fortunately you’ve got a Kenwood TS-990 or an old FT-1000 with 200W output so you turn the power up to full which is another 3dB gain to give you a S6 report.

It’s time to get serious. You spend a load of cash, buy an amplifier, plug it in and and double your output power to 400W (another 3dB) which takes your received signal up to…  wait for it…  S6.5.

If you want to raise your signal to S7, you’d need to increase your power by another 3dB up to 800W which of course you can’t do in the UK.

I’ll give a third scenario.

If you start with 10W and a received signal of S5 and increase your power to 400W, that’s a gain of 16dB which will take your signal up to just over S7.5.

Finally, if you’re running 100W and the station you’re working gives you an S9 report, you’d need to increase power to 1kW to increase that report to S9+10dB or up to 10kW for the report to go up to S9+20dB!

To summarise
Foundation (10W) to Intermediate (50W) power gain = increase of just over one S point
Intermediate (50W) to Full (400W) power gain = increase of one and a half S points
Foundation (10W) to Full (400W) power gain = increase of just over two and a half S points

As you can see increasing power in order to improve your transmitted signal strength really is a case of diminishing returns – You have to double your power each time in order to benefit from just half an S point in signal. It’s far better off to make improvements to your aerial system than to increase power because then not only will the station you’re working benefit from a stronger signal from you but you’ll also benefit from stronger received signals.

In practise, this is what the difference will look like on your s-meter.

Difference in signals between 10W and 400W

Difference in signals between 10W and 400W

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Accurate time keeping on an Apple Mac or Raspberry Pi for WSPR/JT65/JT9/FT8

If you use any of the data modes for QSOs such as JT65, JT9, or FT8 or if you operate using WSPR then you’ll know how important it is that your computer clock is accurate.  Anything more than a couple of seconds out and you won’t decode anything and nobody will decode your signal.

On a Windows computer there are a number of software utilities that keep your clock accurate, one of the most commonly used is called Dimension 4 and most people using the data modes run a third party utility to keep the clock accurate to with a second.

My Mac has always been very good at timekeeping and I’ve very rarely felt the need to use anything additional to keep the clock accurate but I’ve been playing around with WSJT-X on a Raspberry Pis recently and a couple of times I’ve noticed that the clock had drifted just enough to cause a problem.

I started looking into whether there are any third party add ons for the Pi to check and set the clock at regular intervals and found that there was nothing really available but there is an ntp client built into the OS which just sometimes needs a nudge to wake it up or force it to check.

How to automatically set your time using an Apple Mac with Mac OS X

I looked at my Mac first – Mac OS is based on BSD and I figured that if I can do it on the Mac then I can do it on a Raspberry Pi. OS X uses ntpdate to set the time and I decided to force that to run once every ten minutes.  This might be overkill but I’d rather my clock is accurate than not be able to decode stations I’m trying to work.
The first thing to do is to test this to make sure it works.
On your Mac, open a terminal window and type the following:

sudo ntpdate -u pool.ntp.org

You’ll almost certainly be prompted for your password – This is the main administrator account password for your Mac computer, enter it and press return.

After a few seconds, you’ll get a reply which will be something like this:

ntpdate: adjust time server 85.199.214.100 offset -0.009396 sec

You can see my clock was only out by 0.009396 seconds – That’s pretty accurate and is because I run this regularly.

What this command is doing is running ntpdate using the internet cluster of ntp servers to automatically find the closest server to you and set the time.

As you can see, the ability to automatically update your clock is built into the OS but it doesn’t run regularly enough for me.  To force it to run more often, you need to schedule it.  Mac OS has a built in task scheduler called cron and it’s relatively straightforward to add an entry to cron.

By default, Mac OS uses a very powerful text editor to edit system files but that can be a little daunting at first.  If you’re happy to use that then that’s fine, go ahead but I’m going to give you some instructions now on how to change your default system editor to nano.

In your terminal window, type the following:
nano .bash_profile

You will get an empty window just like this:

Copy (cmd-c) the following three lines of text and paste (cmd-v) them into the window:

# Set Default Editor (change ‘Nano’ to the editor of your choice)
# ————————————————————
export EDITOR=/usr/bin/nano

The window will look like this:

Press control-x, press y and then press enter to save the file.

Now either restart your Mac or simply log out and then back in.  If you don’t do this then it won’t use the editor we’ve just configured.

When you’ve logged back in, open a terminal window again and type:
sudo crontab -e

Enter your password as before.

Unless you’ve already added something into cron previously, this file will be empty.  You may have followed my instructions on cleaning a useless cache and if so, there will be a line there already.

It doesn’t matter whether the file is empty or not.
Using your cursor keys. scroll to the bottom and add a new line:
*/60 * * * * ntpdate -u pool.ntp.org

This line is adding a task to automatically run the command we discussed above every sixty minutes. You could change the 60 to be any number you want and it will run at those intervals.  For more information about how to configure cron, please see here.

Press control-x, press y and then press enter to save the file.  You’re done.  Your Mac will now keep very accurate time with no further intervention.

How to automatically set your time on a Raspberry Pi

A Raspberry Pi needs an extra couple of commands to be run first because Raspbian doesn’t come with ntpdate already installed.  Either log onto your Pi via SSH or if you’re using the GUI then open a terminal window and type the following two commands:
sudo apt-get update
sudo apt-get install ntpdate -y

These commands will take a few seconds to run and when they’ve finished, you’ll have installed the required software. You can test this as before using this command:
sudo ntpdate -u pool.ntp.org

Assuming this works OK, you can add the line into cron as on the Mac.

sudo crontab -e

If this is the first time you’ve edited cron on your Raspberry Pi, you’ll see the following screen:

Press enter to select nano and from there, the process is exactly the same as on the Mac.

Using your cursor keys. scroll to the bottom and add a new line:
*/60 * * * * ntpdate -u pool.ntp.org

This line is adding a task to automatically run the command we discussed above every sixty minutes. You could change the 60 to be any number you want and it will run at those intervals.  For more information about how to configure cron, please see here.

Press control-x, press y and then press enter to save the file.  You’re done.  Your Raspberry Pi will now keep very accurate time with no further intervention.

I’ve tested these with MacOS Sierra (10.12.6) using a 2017 iMac and the latest version of Raspbian Jessie on various different model Raspberry Pis including a Pi Zero, Pi Zero W, Raspberry Pi2 and Raspberry Pi3.

Posted in Amateur radio, FT8, JT65, JT9, Raspberry Pi, WSPR | Tagged , , , , , | Leave a comment

CQ WW RTTY 2017

Looking back at my old contest entries, I noticed that I’d never made a serious entry into CQ WW RTTY on 15m in the past and have always concentrated my efforts on CQ WPX RTTY instead. I’ve won the Single Operator, High Power 15m section four times in the past for stations in England and always been reasonably well placed throughout European and World entries.

15m is still my favourite band and I decided to make a proper entry this year into CQ WW RTTY despite the fact that conditions on HF have been steadily going downhill over the last few years as the solar cycle declines and have been pretty dreadful on the higher bands over the course of the summer with major solar flares and storms.

I started operating shortly after sunrise yesterday morning and it took well over an hour of calling before I even made my first contact.  Strangely enough, out of my first twenty or so Qs, half of them were with stations in Finland.

The whole morning was painfully slow, to the extent that by lunchtime, I’d only worked 25 stations or so.  I had a goal to make 300 QSOs on 15m and was beginning to think that this would be totally impossible.  In order to alleviate the boredom, I switched to 20m and worked 65 stations in about 75 minutes.  At least I knew that if 15m carried on as badly, I would be able to run on 20m and get a half decent score.

I needn’t have worried too much though.  I switched back to 15m and after a while, I turned the beam west and started working a lot of stations in North and South America.  I worked Chile, Cuba, Bolivia, Uruguay, Canada, Colombia, Martinique, Sardinia, Argentina, Peru, Lebanon, Brazil and many others.  I was even called by Mike, VP8NO in the Falkland Islands who readers may remember from my sked with him back in 2012.

My day ended on 15m with a total of 250 QSOs in the log.  I even popped back on a bit later in the evening and worked another twenty or so on 40m.

This morning I didn’t start as early and it’s just as well.  When I finally did get on the air at around 08:00z, the bands were in even worse condition than yesterday and it was just slow that I nearly gave up and started learning to knit instead. However I persevered and waited for the band to open to the west again as it did yesterday.  Finally this happened and I was able to make a nice few contacts before it slowed right down at around tea time and I stopped operating at just after 18:30z.

Excluding the 20m and 40m contacts, my final tally was 326 QSOs including 7 duplicates.  You can see a full log analysis by clicking here.  This log analysis is generated by the SH5 utility and enough graphs, charts and statistics to keep everyone happy.

I was pleased to exceed the goal of 300 Qs that I’d set myself.

I worked 45 separate DXCC entities but just 17 of the available 40 CQ zones which goes to show how bad conditions were and 31 States/Areas.   On a plus side, I did increase my RTTY DXCC tally up to 153 even though there were no all time new ones.

Map of stations worked during CQ WW RTTY 2017 on 15m

Map of stations worked during CQ WW RTTY 2017 on 15m

As can be seen above, I worked far more non European stations than Europeans and here’s the breakdown.

Breakdown of continents worked during CQ WW RTTY 2017 by G6NHU

Breakdown of continents worked during CQ WW RTTY 2017 by G6NHU

It’s been a number of years since I made any serious contest entry – I’m used to 15m being a busy and bustling band with lots of Europeans, then a bunch of JAs from mid to late morning and bucketloads of Americans in the afternoon.  I knew conditions would be poor but wasn’t really expecting things to be quite so bad.

The afternoon runs to North and South America were nice though and they’re reflected in the breakdown of countries worked.

Top 10 countries worked during CQ WW RTTY 2017 by G6NHU

Top 10 countries worked during CQ WW RTTY 2017 by G6NHU

I enjoyed operating the contest this weekend and am looking forward to the results in the forthcoming months.  It was nice to get stuck in and get my hand back in operating.  I still use fldigi for operating contests and I’m confident and comfortable using it. Over the years I’ve put together macro files for all the contests I’ve operated in and they work very well. I’m sure that there are better tools available for data contesting but it’s what I know and I like it.
If anyone wants to have a look at my fldigi macro files or would like help with getting started with fldigi, please contact me either by adding a comment to this post, via the contact page on this site or by email using my address on qrz.com

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Time for a new aerial, I’ve replaced my doublet with an OCFD

Earlier this year I decided it was time to replace my doublet with a new wire aerial.  There was nothing actually wrong with the doublet, I’ve worked plenty on it but it always galled me that I had a smarttuner connected to it which limited my transmit power.  I could only run 100W SSB or 30-40W using any of the data modes.  Apart from anything else, it had been there since 2013 so it really was time for a change.

I decided to hang either a dipole for 40m or an OCFD with 40m as the main band and make sure it was capable of taking full legal power on both SSB and data.  That meant having it resonant and with a good enough balun to handle the power.

Logically this meant that the feed point would need to be supported because a decent balun with that sort of power handling would be too heavy and cause the feed point to sag too far if it was only supported at the ends.  I also wanted to try and utilise any existing potential aerial supports in the garden and after some measuring, pacing and head scratching, I decided to go with an OCFD.

An OCFD is an off centre fed dipole where as the name suggests, the feed point is moved from being right at the centre to approximately one third of the way from one end.  Rather then present a 50R impedance to the wireless. this configuration presents around 200R.  This is transformed to the more normal 50R by the use of a 4:1 balun.

I appreciate that an OCFD is a bit of a compromise aerial and that I when I made one before, it was only there for a month before I replaced it but I wanted to try again.

My search for a suitable balun led me again to Balun Designs.  I used one of their products before when I replaced the balun on my MA-5B so I knew that they’re good.  After exchanging emails with Bob, KZ5R, I ordered a 4115ocf.

Unfortunately the package got held up in customs so not only was it slow to arrive but I got stung for import duty, VAT and the ridiculous ‘handling’ fee which is added on top of the other charges.  This turned out to be an expensive balun.

It looks good though (all the pictures in this post can be clicked for much larger versions).

Balun Designs Model 4115ocf 4:1 balun

Balun Designs Model 4115ocf 4:1 balun

It looks even better with the cover off.

Inside of the Balun Designs 4:1 Model 4115ocf balun

Inside of the Balun Designs 4:1 Model 4115ocf balun

While this was on the way, I sorted out everything else – I got myself a 20ft pole and started looking at different types of coax. It took me a while to decide what cable to buy as I’d seen a tweet mentioning a company called Messi & Paoloni who I’d never heard of before.  I found their online catalogue and spent a long time poring over the huge range of cables before ordering 25m of Airborne 10.  The claimed loss is really rather low at less than 0.3dB for 25m on 7MHz with a power handing of over 6.5kW on that band.  At 28MHz the loss for the length I’d be using is just under 0.5dB with a power handling ability of nearly 4kW.  Of course, these power levels are far more than I’m ever going to use or would want to put anywhere near a PL-259.  It’s good to over spec everything.  This is also one of the lightest high power/low loss cables they sell which was another good reason for choosing it.

Unfortunately, when the cable arrived, it wasn’t quite what I expected.  It uses an unusual material for the outer jacket, it’s not very flexible like RG213, it’s somewhat plasticy and feels like the old H100 (if anyone remembers that).  Once bent into place, it stays there.  It would work but I knew I’d have to be very careful when routing it in the shack.

When I started getting everything ready in the garden, I discovered a big problem.  I’d planned to mount the 20ft pole on an existing pole in the garden which supports a washing line but somehow, despite all my careful measuring and pacing, I realised that wouldn’t work.  One aerial end was far too long for the end supports I’d planned and the other was too short.

Luckily, we had another washing line support pole and this was perfectly located but it meant my feed point was now much further down the garden that I had originally planned.  No real problem except the coax I’d bought wasn’t long enough.  I decided that rather than buy a complete new length, I’d extend the existing run and so I bought 10m of Messi & Paoloni Ultraflex 7.  I only needed to use 5m and so I made five good patch leads with what was left over.  The power handling isn’t anywhere near as good as the Airborne 10 and it’s lossier but I didn’t really see either as a problem.  On the plus side, this is nicely flexible and works well in the shack.

With these problems overcome, I set about getting the aerial up.  I mounted the balun to the top of the pole and also managed to extend the feed point support pole so it that it was 25ft up in the air.  It also helps that this washing pole is right by a tree so my support goes almost through it.  My two legs measured 12.14m and 8.28m and I didn’t change these at all once the aerial went up.

Feed point of my OCFD - Around 25ft AGL

Feed point of my OCFD – Around 25ft AGL

You can see from this the following two pictures that the feed point was absolutely perfect here, the leg lengths are spot on for my two end points.

Far support pole holding my OCFD

Far support pole holding my OCFD

The end of the OCFD on my main mast

The end of the OCFD on my main mast

The important question to ask after all this, is does it work?

The main band I built it for is 40m and since putting it up, I’ve worked all over Europe including the Netherlands, Germany, Finland, Sweden, Italy. Hungary, Serbia, Slovenia, Romania, Russia, Ukraine, France, Poland, Portugal, Spain, Czech Republic, Denmark and many others.  I’ve also worked Gabon, the USA, Iceland, Argentina, the Canary Islands, Canada and Brazil using it.

I think the answer to that question is “yes, it works”!

Additional
I ran 0.001W (1mW) of WSPR up the OCFD on 40m for 24 hours when conditions were absolutely dreadful and was received by the following stations.

1mW of WSPR over a 24 hour period through my OCFD on 40m

1mW of WSPR over a 24 hour period through my OCFD on 40m

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SCC RTTY Championship 2017

It’s been some considerable time since I put in any serious contest entry and I’ve been looking for the chance to do it for a few weeks.  I sorted out my data problems a while ago and have been happily able to operate RTTY, PSK, etc ever since.  I’ve been looking for a data contest with a section for a 15m only entry.

I’ve said before that 15m (21MHz) is my favourite band and I like the fact that I can work a contest until the band closes in the evening and then pick it up the following morning.

This weekend was the SCC RTTY Championship which is a contest that I’ve never entered although I did give away a few points back in 2011.

Bearing in mind the solar conditions recently, I expected it to be slow but I didn’t expect things to be as slow as they were.  Conditions were absolutely dreadful with just 73 QSOs made on Saturday.  I had the reverse beacon open to see where I was being received and there were very few spots being reported.  I also had the WSPR map available so I would see when any WSPR signals started crossing the Atlantic and I’d know roughly when to start beaming that way.  There were no WSPR spots whatsoever between the UK and the USA on 15m and although I did try pointing the aerial that way for a while, there were no RBN spots of my callsign either. I worked EA8PT in the Canary Islands, left my beam pointing that way for a while and was lucky enough to make a QSO with CV7S in Uruguay but that’s the only DX QSO worth reporting.

Sunday morning was livelier but still nothing to write home about with no unusual QSOs, just lots of European stations calling.  I operate pretty much exclusively by calling CQ during data contests and settled into a nice routine where the rate was slow, so I could do other stuff as well.  In the end I finished with 190 QSOs in the log of which six were duplicates.  One station called me four times but I always work duplicates in case they’ve made a logging error and got my callsign wrong – By working dupes, I can at least hope that they’ve got my call correct on one of the instances.

This contest uses “four-digit number of the year of operator’s first ever official amateur radio licence” as the exchange and the multiplier and I received them from as early as 1947 (a club station) up to 2017.  Out of a range of a possible 70 multipliers, I received 57 different years back.  I think that’s quite a decent result.

Top 10 countries worked by G6NHU in the SCC RTTY Championship 2017

Top 10 countries worked by G6NHU in the SCC RTTY Championship 2017

As this contest is run by the Slovenia Contest Club, it’s not surprising to see that Slovenia is right near the top of the list of countries I worked (click the chart for a less blurred version).

You can see other interesting graphs, charts and a full and very detailed log analysis by clicking here.

On the whole, this was an enjoyable contest and a good chance for me to get my hand back in.  It was slow, very slow and conditions were (to be blunt) bloody awful.  It was fun to operate it though and good to see that my station still works, even considering how bad things were, RF wise.

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