Tuesday, 18 August 2015

Current solar conditions added to propagation chart pages

I've just made some changes to my monthly propagation charts.

I've added some more data sources so that you can see the current solar and geomagnetic conditions as well as the predicted HF coverage maps from the UK.

This means that you can get an at a glance look at likely HF propagation conditions – all on one page. The data include the current solar flux index, the Kp index and also solar wind characteristics.

We have been suffering from a number of recurring coronal holes recently (areas on the sun where the magnetic field is weaker, letting plasma out to form the high-speed solar wind).

If the magnetic polarity of this solar wind is “south” (we say that its Bz is pointing south) it is more likely to couple with the earth's magnetic field and the hot plasma can flood in.

The net result is the earth's magnetic field is distorted and we see this reflected in the Kp index, which normally rises - a geomagnetic storm is in progress.

The initial effects can be a short improvement in HF conditions, but these can be short lived. We then see an overall drop in maximum useable frequencies, the bands can get noisier and signals drop away, often with lots of heavy fading (QSB). It can take 24-48 hours for the ionosphere to recover, if it is not hit again.

The net effect is a lowering of overall critical and maximum useable frequencies as the plasma hits and excessive absorption, especially on polar paths.

We've seen a lot of this recently with poor conditions on HF.

So for good HF conditions look for settled geomagnetic conditions with a low K index for a day or so, a low solar wind speed (less than 450 km/s) with a Bz that is neutral or pointing north and a high solar flux index.

If you have a high Kp index, a high solar wind speed and a Bz pointing south don't be surprised if the bands aren't so good! This would not normally be seen in the monthly charts, which are an "average" for the month.

The charts are also now being carried on the RSGB web site too at http://rsgb.org/main/technical/propagation/hf-propagation/uk-short-path-monthly-forecast-maps/ which is why I have kept them long and thin to fit into the frame on RSGB.org.

Tuesday, 14 July 2015

UK astronaut Tim Peake announces shortlist for amateur radio contact with ISS

UK ESA astronaut Tim Peake.
Image: Steve Nichols
I wanted to be one of the first to break this news from Liverpool, especially as Norwich School is local to me. Congratulations to the school for making the shortlist for a two-way contact with Tim Peake when he is on his six-month mission to the International Space Station, currently targeted for December 2015 or later.

Here is the full announcement:

The shortlist of UK schools that will have the opportunity to contact British ESA astronaut Tim Peake via amateur radio during his mission to the International Space Station (ISS) has been revealed today at the UK Space Conference.

Tim will launch to the ISS in December of this year and will spend six months working and living in space. The Amateur Radio competition is a collaboration between the UK Space Agency, the Radio Society of Great Britain (RSGB) and the European Space Agency (ESA).

Selected schools will host a direct link-up with the ISS during a two-day, space-related STEM workshop which will be the culmination of a large range of learning activities using space as a context for teaching throughout the curriculum.

ARISS UK (Amateur Radio on the International Space Station) will provide and set up all necessary radio equipment such as low earth orbit satellite tracking antennas and radios, to establishing a fully functional, direct radio link with the ISS from the schools’ very own premises. In a ten-minute window when the ISS will be over the UK, an amateur radio contact will be established with Tim, and students will be able to ask him questions about his life and work on board the ISS.

Owing to the nature of scheduling the links, which is dependent on geography, the  exact orbit of the ISS and the crew schedules, the exact dates and times for possible links will not be known until 2 weeks before the link up is scheduled.  The shortlisted schools will all be prepared for such scheduling challenges and, by having a number of schools, we can ensure that all links are used. 

Jeremy Curtis, Head of Education at the UK Space Agency, said: “We’re delighted with the amount of interest in this exciting project and look forward to working with the selected schools as they make a call into space.

“Both Tim’s space mission and amateur radio have the power to inspire young people and encourage them into STEM subjects. By bringing them together we can boost their reach and give young people around the UK the chance to be involved in a space mission and a hands-on project that will teach them new skills.”

The following schools have been shortlisted for a possible ARISS call with Tim whilst he is in orbit on the ISS:
  • Ashfield Primary School, Otley, West Yorkshire
  • The Derby High School, Derby                   
  • The Kings School, Ottery St Mary               
  • Norwich School, Norwich
  • Oasis Academy Brightstowe, Bristol           
  • Powys Secondary Schools Joint, Powys  
  • Royal Masonic School for Girls, Rickmansworth          
  • Sandringham School, St Albans                
  • St Richard’s Catholic College, Bexhill-on-Sea 
  • Wellesley House School, Broadstairs        
John Gould, G3WKL, President of the RSGB, said: “The Radio Society of Great Britain will be delighted to support shortlisted schools by teaching their pupils about amateur radio and helping them through their licence exams where appropriate. Members of our Youth Committee are based across the UK and will be keen to visit the chosen schools in their area and chat to the pupils.”

The ARISS UK Operations team will now work with the shortlisted schools to prepare them for this exceptional opportunity during the mission of the first British ESA Astronaut.

Thursday, 9 July 2015

New "Spitfire" 20m Rockmite ][ QRP CW transceiver is born

Click to view larger image
I was walking around a local shop recently when I spotted a range of mints in tins from a company called Stewarts.

They are very attractive and feature paintings of a Supermarine Spitfire, a steam locomotive and a Triumph motorcycle.

At just £2.99 each the tins are cheap and cheerful, and I knew just what I wanted to do with one!

Hence, the plans for a 20m Rockmite ][ transceiver were born.

I have built a 40m Rockmite v1 before, which is a crystal-controlled ham radio transceiver offering about 0.5W output on two very close frequencies – you select each one by pressing a button. The Rockmite also has a built-in CW keyer with a speed control and is a very simple, but well-respected little radio.

The joy is they will fit in a mint tin, such as the famous Altoids. But the Stewart tins are much more attractive.

So, I ordered a 20m Rockmite ][ from Kanga kits (www.kanga-products.co.uk) in the UK (they are actually made by Rex Harper of QRPme.com in the US) and it arrived the next day.

The box is easy to work on as the material is very thin. I carefully took the lid off while I was working on it and wrapped the rest in masking tape to protect it and allow me to drill the holes. Quick tip – run a pencil around the lid when it is closed so that you can see on the tape where the lid will be when it is assembled. You can then measure and drill the holes for the antenna jack, power, key, headphones and frequency switch knowing that they won't bind on the lid.

Click to view larger image
I used a sharp, new 2.5mm drill for all the holes after marking them with a centre punch first. I then used a Dremel tool and needle files to open up the holes to the size needed. With hindsight I would have moved the PCB a little closer to the antenna side of the box to give more room, but I have now managed to put it all together.

The PCB build was simple, but I did end up with some spare components, which worried me! I didn't miss anything, so I thought they must be spares.

Dennis G6YBC of Kanga subsequently emailed and said: "Apologies if the spare parts (bits left over) confused you. I enclose all parts to complete the Rockmite ][ in either of ways that Rex explains i.e. with volume and speed control etc.

"This includes extra resistors for the various mods that he and Chuck have published. This includes the 3866 and 2N2222 transistors. All the above parts are part of the BOM as per the build instructions for Ver 3, but you also have to read the other sheets Rex publishes on his website."

I also had to modify the layout by cutting a track and adding a resistor, but that was easy.

I had the choice of a 2N2222A (TO-18) transistor or a 2N3866 (TO-5). I chose the latter as I presumed it would give a higher output – wrong, as we'll see later!

I also swapped the BNC for a phono socket to match the Mountain Topper Radio (MTR) I also have, which I have written about before.

By soldering on all the connectors I was able to test if on the bench first before boxing to make sure everything worked, which it did (that's unusual for me).

Powering up the the Rockmite gives a “73” in CW through the headphones, which is a nice touch. You can switch to a straight key by holding down one of the paddles or the key on power up. You can also change the speed by holding the button down for more than half a second and then using either paddle to speed it up or slow it down – the speed in WPM is enunciated in CW.

The first tests were a little disappointing as summer afternoons are not the best for 20m. But the evening and next morning showed the little receiver is very lively, picking up stations in the US, Switzerland, Germany, Czech Republic and others with a dipole at about 25ft.

The rig is actually on 14.0604MHZ and 14.0598MHz as far as I can see.

So does it transmit? Yes, but only about 200-250mW with a 12.4V supply. I think the output can be tweaked a little higher, say 500-700mW by reducing the value of the R18 resistor, but I need to check on that.

Needless to say, I haven't managed to work anyone on it yet – it is a little too QRPP for me! I was picked via the reverse beacon network in Germany and Ireland though.

All in all though, it is a pretty little radio with a very nice receiver around the QRP frequency of 14.060MHz. Next step is a 40m FOXX-3 transceiver in the steam train mint tin I think.

Update 10th July 2015
I put a quick CQ out last night and was picked up on the VE2WU skimmer in Quebec. That's pretty impressive! 

Tuesday, 7 July 2015

Propagation maps updated until end of 2015

I had a bit of free time this morning and have now updated the HF propagation predictions maps for the UK through until the end of the year.

The original charts for July to December 2015 were from last year and were based on the smoothed sunspot numbers (SSNs) for that period. Now, they have been redrawn using the new predicted SSNs.

You can just pick the month you wish to look at at http://www.infotechcomms.net/propcharts/

Also, please note that I now produce the weekly HF predictions for the RSGB's GB2RS service. These are also published online every Friday at: http://rsgb.org/main/news/gb2rs/

I write the HF section and John G4BAO and Jim G3YLA complete the VHF and up part of the broadcast. If there is anything you would like to see added or changed please let me know at steve[at]infotechcomms.co.uk

Friday, 12 June 2015

Getting Started In Amateur Radio

My latest book "Getting Started in Amateur Radio" is now available from RSGB.org.

If you want to know something about the hobby or are newly licensed, or are even just looking for something different, "Getting Started in Amateur Radio" helps provide the answers.

What about receiving digital images from the International Space Station? Or talking to friends around the world via satellite? Or perhaps being able to help out during natural disasters? All of these things are possible with amateur radio and the book details these and many other possibilities.

It provides information on the activities to explore when using your first VHF/UHF or HF station and what other equipment you might need. There is a section on practical antennas and details of operating using CW (Morse code), FM, SSB, Digital and more. What you can expect from the different amateur radio bands is covered and there is even a section devoted to long distance operation (DXing), amateur radio contesting, and amateur radio awards.

The coverage doesn't stop there and readers will also find the microwave and LF bands discussed along with Moonbounce or Earth-Moon-Earth transmissions (EME). There is even a practical guide to getting a licence if you don't already have one.

It is aimed at prospective UK licensees, but there is something for everyone wherever you are. We've also kept the price as low as possible to encourage new amateurs.

Monday, 16 February 2015

Partial solar eclipse propagation experiment, March 20th 2015

The RSGB Propagation Studies Committee (PSC) is keen to encourage radio amateurs to take part in an experiment during the partial solar eclipse taking place on Friday 20th March 2015.

The path of totality will pass north of us, over the Faroe Islands, but the UK will experience up to 89% totality (depending upon where you live).

This is a great opportunity to try some simple experiments to see how the sun’s ultra violet output affects our ionosphere and how some radio waves are propagated.

On the morning of Friday March 20th 2015 the D layer above the UK may not be as strong due to the eclipse, and you may be able to hear stations on the lower bands – 1.8 MHz, 3.5 MHz and perhaps 7 MHz that would otherwise be inaudible during the day.

For example, if you listen for a medium wave radio station that is more than 250-300 miles away during the day you may not hear it – it is too far away for its ground wave signal to reach us, and any sky wave signal is absorbed by the D layer of the ionosphere.

But at night its sky wave signals are not absorbed as there is no D layer and they are free to be reflected back to earth from the higher E/F layers.

This is why you can hear distant medium wave stations on a radio at night, but they aren’t there during the day. You get a similar effect on Top Band, and to a lesser extent 80m/40m.

We are keen to encourage radio amateurs to conduct experiments during the eclipse, especially if they can use software defined radios (SDRs) to record the whole eclipse period for later analysis using Spectrum Lab or similar, or if they can use WSPR.

For the latest information see the RSGB site.

PSC has also devised a simple experiment for schools to undertake using portable medium wave radios. A PDF flyer about the eclipse propagation experiment is available to download here.

The information we gather will also be shared with the Rutherford Appleton Laboratory at Harwell.

The partial eclipse starts in the Midlands at about 08:25 GMT on Friday March 20th and ends at 10:41 GMT. Maximum eclipse will be at about 09:30 GMT.

Monday, 5 January 2015

UK HF Propagation Prediction maps

I have now updated my UK HF coverage prediction maps for this quarter using the current smoothed sunspot numbers (SSNs). The maps for April to December can be used as being representative, but will be updated as and when the SSNs are updated later in the year.

On the current evidence it looks like we passed the peak of Sunspot Cycle 24 in the Spring of 2014. However, the cycle still seems to have some life left in it.

The peak solar flux index (SFI) for the cycle occurred on 23rd October 2014 with 227, although there were plenty of other times when it bettered 200, including January 2014, October and December 2014.

On an annual basis, 2014 had the highest average daily sunspot numbers of any year since 2002, according to the ARRL, although the peak solar flux indices were higher in 2002, hitting 261 on 29th January 2002.

The highest peak solar flux indices of cycle 23 were actually seen in 2001, with 283 being reached on 26th September 2001. This cycle has been poor in comparison.

But what next? What has been very apparent is the general increase in solar flares and coronal mass ejections (CMEs) recently. This has led to disturbed geomagnetic and HF conditions and is typical of the downward trail away from a sunspot maximum.

Over the next quarter we can expect to see overall sunspot numbers decline slightly, with solar flare and CME activity remaining high. Expect to see SFI numbers in the range 120-180, still good enough to provide good openings to DX on the higher bands at times.

We may see the cycle peak up yet again before it finally tails away, but are we likely to see the SFI go above 200 again? Who knows.

You can see my UK HF prediction maps at http://www.infotechcomms.net/propcharts/ or use the link top right.