Friday, 27 May 2016

Updated UK HF prediction charts

I've now updated my hourly UK HF Propagation Predictions maps for the rest of 2016.

You can view the charts using the link on the right or at

These take into account the latest smoothed sunspot numbers from NOAA/NGDC.

We continue to see a steady decline in sunspot activity as we fall away from the peak of solar cycle 24. Twelve months ago the solar flux index peaked at 163 in May. This month it has struggled to exceed 100 and is currently 94.

Coupled with this, we have suffered quite badly from the effects of plasma from solar coronal holes. These are areas of the sun with an open magnetic field that allows plasma to escape.

If these coronal holes are earth-facing the result can be an elevated K index as the plasma from the high-speed solar wind stream impacts the earth, especially if it has a negative or south-facing magnetic field, which couples more easily.

A high K index is usually a sign of poor HF conditions, with noisy bands and depressed maximum usable frequencies. Any path over the poles is also badly affected.

This can also lead to aurora, which while not being visible in the summer, can lead to openings on VHF.

The RSGB Propagation Studies Committee is also pleased to be able to present its latest HF propagation prediction tool, which is currently hosted at

This is still being developed and uses the newer ITURHFPROP software as its backend, rather than VOACAP.

We encourage amateurs to use the system, which can also be used for point-to-point predictions using a prototype tool called 'Proppy'.

Gwyn G4FKH, who is project manager for the new system, welcomes feedback. The goal is for the whole system to be moved to the RSGB website once finished.

Thursday, 19 May 2016

Sporadic E season is under way

The Sporadic E (Es) season on 10m and 6m is well under way with lots of useful openings.

I was having a listen around 28MHz today and was struck by how many 10m beacons are audible when there doesn't appear to be any other activity on the band.

And they aren't high powered either. First I heard OK0EG on 28.2825MHz in the Czech Republic and a little late OY6BEC in the Faroes on 28.235MHz. Then a little later still I spotted a spike on the IC-756 Pro3's panadapter and it was F5ZWE near Toulouse on 28.2427MHz.

You can get a current list of 10m beacons, complied by Martin G3USF, at:

These are all running 10-15W and simple antennas, yet can reach S6-9 in the UK when the conditions are right.

We still don't completely understand Sporadic E, although the current thinking is that it is due to wind shear in the upper atmosphere that pushes ions together into clumps or clouds. The ions may come from meteors. Jim G3YLA, who is a professional meteorologist, is also looking at whether these winds, when they pass over mountain ranges, are forced upwards and create these "gravity waves" that force the ions together.

I also have a theory that solar flares can contribute to SOME of the ionisation on occasions, but mainly outside of the May-August period - there are plenty of instances of Es without any flare activity. I have some plots of Es in late April that correlate very well with solar flares.

Anyway, Jim posts some daily high-level wind charts in an attempt to understand what is happening. 

Steve G0KYA

Thursday, 14 April 2016

International Marconi Day, April 23 2016

Saturday 23rd April 2016 is International Marconi Day when stations around the world celebrate the birthday of Guglielmo Marconi.

It is also a good opportunity for you to gain a very nice certificate. All you have to do is work 15 award stations and send in a log extract - you don't need QSL cards.

I shall be helping to run GB0CMS again this year at Caister Lifeboat in Norfolk, UK.

There is short video that looks at the equipment the club used to make 165 contacts in 24 countries on Saturday 30 April 2011. And another for the 2012 event when we made more than 500 contacts.

See and

To help UK stations work the requisite number of IMD stations I have prepared some HF propagation predictions. You can view these online.

You can find out more about IMD at:

Friday, 4 March 2016

Working the International Space Station with 2m APRS

The proof - G0KYA works RS0ISS as shown
at, along with other EU stations.
Yippee! It works! Yesterday I wrote about how I had managed to get 2m APRS working on my Icom IC-7400 using Soundmodem, UISS and a program by G8BPQ to connect a virtual comm port to the Icom CI-V interface to key the radio.

It all seemed to work on terrestrial APRS on 144.800MHz, but the acid test was whether it would connect with the APRS system on the International Space Station (ISS) on 145.825MHz.

I already knew that it could decode packets from the ISS, but would the ISS be able to decode me?

So this morning it was time for a test. Using a 2m Slim Jim in the loft, I wound the Icom IC-7400 up to half power and waited for the ISS pass between 10:11-10:20hrs. This was a maximum 73 degree pass here in East Anglia.

Actually – small confession. I thought the IC-7400 was a maximum 50W out on 2m, when it is actually 100W (when I looked at the manual). So I was actually using 50W not 25W.

The 50W power might be a little excessive, but my coax is only RG58 (although it is only about 12m) and the antenna is a compromise in the attic too, so the ERP was probably more like about 20-25W. I figured that if I could connect with 50W I could reduce it on other passes and see what QRP power would do.

This attempt was just to prove that the system (with a software modem and not a packet TNC) could work.

Anyway, using the UISS program I put in my locator square (JO02NN) and details and waited for the pass.

The ISS became audible at about 10:13hrs and I adjusted the rig's frequency to about 145.828MHz to allow for Doppler.

The system decoded quite a few packets and I keyed the UISS APRS TX button.

The Doppler shift fell away as the ISS got closer and at 10:16:09hrs I was successful – RS0ISS heard G0KYA. Yippee! So now I can apply for the ultimate QSL card.

You can check whether you have been heard at and this will also plot your location on a map. You can get the details of how you apply for a QSL card at:

Some learning points though:

1. Spend some time getting your latitude and longitude absolutely spot on. Just using the locator square of JO02NN put me about half a mile away from actual location. The easiest way to do this is with APRIS32 and zooming in on the map to get the exact degrees, minutes and seconds of your lat. and long.

2. Keep an eye on the Doppler shift. This can vary from about +3.5kHz to -3.5kHz over the whole pass. Orbitron will calculate this for you. It does mean that at AOS your TX frequency will have to be lower than 145.825MHz and you you will listen higher. At the time of closest approach they should be both be about 145.825Mhz, and that might be the best time to attempt the contact.

3. Use a small beam rather than an omni-directional antenna. I have a tiny three-element delta loop beam that I may fix pointing due south at about 35 degrees elevation to see how that fares. It might be better for the ISS, PSAT and the other satellites.

4. Use better coax. RG58 isn't ideal for VHF – the only reason I used it was because I normally use that run for HF. I had three lengths put in between the shack and the loft when I first moved in. As it is only about 10-12m long the losses are about 2dB on 2m. Low enough for the limited VHF work I do, which normally amounts to local 2m FM work only.

But as an experiment the ISS APRS contact via Soundmodem worked, showing you don't need to have a hardware packet TNC to work the ISS on APRS - or complex antennas.

Update 5th March 2016

I reconfigured the station for my daughters, who are both licensed. At 07:48hrs Ellie M6ELE got through with 10W. Her digipeated signal was captured from the ISS by PD0SBH-10 in the Netherlands.

On the next pass Sarah M6PUP also got through with 10W and the return signal was picked up by ON7EQ-10, so my thanks to both stations.

Jean-Jacques ON7EQ has a stonking ground station - see

Thursday, 3 March 2016

2m ISS APRS on the Icom IC-7400 with Soundmodem

The UISS software for sending packets to/via the ISS.
After my recent work on the Tim Peake ISS contact project I was quite taken with the idea of being able to contact the ISS using 2m APRS data on 145.825MHz.

I haven’t really played with packet radio for years and sold my TNC in the dim and distant past. But I read that you can use a software-based modem now instead of a TNC.

I already had a data interface that would work with my Icom for RTTY and PSK31.

So it couldn’t be that hard to get APRS running, could it? I never learn!

Firstly, we have got two APRS experts in my local club (Norfolk Amateur Radio Club – James M0UKS and Kevin M0UJD who could write a book on the subject), but even a chat with them left me none the wiser. But I eventually figured it out, so thought I would share the details.

The problem is that Soundmodem (the software modem that you can use for APRS) expects to see a signal on a serial port to transmit or key the PTT. Icom, on the other hand, uses its CI-V interface to send a command.

I messed around with this for days, but eventually came up with a solution, thanks to John G8BPQ. He has written a small program that creates a virtual serial port. He then has another program called CAT7200 that translates the rig’s CAT control command and sends it to the virtual serial port. The result is that the rig then transmits.

So what do you need to set up APRS on an Icom IC-7400 or IC-746 Pro? I would imagine that this would work with the IC-706, IC-7000 and IC-7410 too.

Firstly, I’ll presume you have a data interface for RTTY/PSK connected up and working with your PC. Secondly, I’ll presume you have a CI-V interface connected between the radio and the computer too – the type that sends the frequency and other information to your logging program, for example.

Now you need to do the following:

1. Download and install Soundmodem from

2. Download and install UISS from

You should be able to configure the two programs and receive packet data on 144.800MHz (if in the UK) or from the ISS or PSAT on 145.825MHz.

Quick tip – make sure Soundmodem is set to look for tones on 1200/2200Hz – I must have changed mine by mistake and although I could see the packet tones on the waterfall it wouldn’t decode.

Orbitron let's you work out when the ISS is overhead,
as well as other packet-enabled satellites like PSAT.
I won’t go into any more detail on UISS or Soundmodem as there are better reference documents out there, but if you’ve got this far you are half way there.

Now to enable TX.

Go to and download the file Unzip it into a suitable folder.

Now go to back to the CAT7200 web page and follow John's instructions for creating a virtual serial port using the files you have just downloaded – there are instructions for XP and Windows 7.

Once you have created the virtual serial port it should appear in your Control Panel. You now set up Soundmodem to trigger this Com port in devices >> PTT Port.

Now the clever bit. Run CAT7200 and set it up to watch the virtual serial port you have created (on the left of the screen) and to trigger the CI-V CAT port you use (on the right of the screen).

Now, if you send a packet from UISS it should put the radio in TX first. Just make sure you get your audio levels right.

As for how you send a data packet to the ISS please see

Friday, 26 February 2016

Today's Tim Peake ISS contact was a great success

I was so proud to be part of the team that let youngsters talk to astronaut Tim Peake on the ISS from the CNS School in Norwich today.

There wasn't a dry eye in the hall!

The lowish six-minute pass went incredibly well thanks to the technical team from ARISS.

Each of the youngsters got to ask a question and we even got in a few more. Good video link too.

Norfolk Amateur Radio Club has been heavily involved in the event and helped run workshops at the recent "Ground Control" day.

Our special event station with the call MX0YHC also made around 100 contacts on 40m thanks to Chris G0DWV and Andy M0NKR.

I have a whole host of images from the event.

Good luck with the next link-up

Sunday, 21 February 2016

Worked All States, QRP and magnetic loops

MFJ-1786 magnetic loop for 30m-10m
This weekend was the ARRL CW DX contest where US stations work the rest of the world. This was a good opportunity to try and work the rest of the states I need for my Worked All States award.

I need Alaska, North Dakota, South Dakota, Wyoming, Rhode Island, West Virginia and Nebraska.

I have actually worked quite a few of these, but those stations are not on Logbook of the World (LOTW).

Anyway, starting at the bottom of 14MHz I soon came across KI1G in Rhode Island and bingo! He was in the log with 100W to the OCFD.

I never found any of the other states I needed, but on Sunday I came across N8II in West Virginia and bingo, worked him too. Unfortunately, he isn't on LOTW – damn! I'm not sure if you can do a mixed entry with part LOTW and part QSL cards, like I did with my DXCC application. It might come to that.

Anyway, with no sign of the Dakotas or Nebraska (don't even mention Alaska), I thought it would be fun to try some QRP.

With just 5W I soon worked Connecticut, Pennsylvania and Massachusetts with the OCFD. Time to up the game.

So I rigged up my MFJ-1786 mag loop on a 12ft pole in the back garden. This was about two S points down on my usual 40m half-wave OCFD, but I was able to work the eastern states on 20m in very short order. I also worked N2IC in New Mexico, W2UP Colorado and N9RV Montana on it.

So what about QRP and a magnetic loop?

A bit harder, but North Carolina, Tennessee, Vermont and Virginia were soon in the log with 5W on 15m.

Now, don't get me wrong, it is the antenna at the other end of the contact that was doing all the hard work, but if anyone says they haven't got room for HF antennas tell them about the MFJ-1786. It's a miracle for hams with little space.

So I'm hoping that Rhode Island gets confirmed on LOTW. I then need to think long and hard about Alaska. That is going to be a tough one. And if I can get the others confirmed with QSL cards Worked All States (WAS) is a possibility.