Short path propagation charts from the UK

I have now updated my short path HF propagation charts for the UK for the next three months – November, December and January.

These have been created using the latest smoothed sunspot numbers from NOAA in the US and HAMCAP.

October was a fantastic month for 10m propagation with most of the world being workable at times. Early November saw a dip in the solar flux index, which manifested itself as poorer conditions overall.

But the flux has been climbing steadily over the past few days and is back in the 130s again so 10m is opening up nicely.

We just have to worry about solar flares and coronal mass ejections, which could be a fly in the ointment. Solar flares can bring short-lived D layer absorption, while coronal mass ejections, if earth facing, can bring about depletion of the F layer for many days.

Look out for a high solar flux index (>120) and a low K index (0 or 1) at www.solarcycle24.com for the best HF conditions.

The low bands are also coming into their own with the extended periods of darkness in the northern hemisphere.

Keep an eye on 80m – there will be good openings on 80m, and 40m has been open to parts of the US way past sunrise over the last week.

December should be a good month for the low bands, including Top Band (160m) although probably not as good as we have seen a few years ago around solar minimum.

The November propagation chart can be found at: www.infotechcomms.co.uk/propcharts/november/ 

A link to all of the charts can be found top right.

Video of trip to K6KPH, California

I was lucky enough to visit the Maritime Radio Historical Society's old KPH sites at Bolinas and Point Reyes, California, in September.

If you haven't heard of these they were the transmitter and receiver sites for KPH - the mighty Pacific coastal station that sent Morse code and RTTY to ships and point-to-point services until the late 1990s.

Both sites are now restored and they also run K6KPH - an amateur station. They were kind enough to let me operate some CW as well, letting me make contacts across the USA on 14MHz.

You can find out more at: www.radiomarine.org

I shot a seven-minute video while I was there too - you can see us working G3LDI back in the UK on 20m CW. Go to https://www.youtube.com/watch?v=Wj-IwYPrtTM

More free propagation books

The late Bob Brown NM7M was an expert on ionospheric propagation. He wrote a number of great books and two of these are now available as free downloads on Carl K9LA's site.

The first is the The Little Pistol's Guide to HF Propagation

The second, on Top Band (160m propagation), is NM7M The Big Gun's Guide to Low-Band Propagation

Carl has a lot more useful information as well - see just go to http://k9la.us/

Steve G0KYA

RSGB Convention, October 2012

I will be giving two presentations at this year's RSGB Convention - one on using HF propagation prediction programs and the other on modelling antennas using MMANA-GAL.

I have made the presentations available as PDF downloads should anyone want them. I'm not sure they will make a lot of sense without the accompanying talk, but you are welcome to them anyway.

Don't forget there is a free book that you can download that explains a lot about HF and LF propagation - see the link on the right.

Here are the links: 

• Using HF Propagation Prediction Programs (1.7Mb PDF)
• Modelling antennas with MMANA-GAL (8.4Mb PDF)

Special Olympic call – GO0KYA

To celebrate Great Britain hosting the Olympic Games we are allowed to apply for a special notice of variation to our licence. This allows us to add the suffix “O” to our calls.

So until early September I can use GO0KYA. I tried it out the other day and within half an hour on 40m CW I had worked the Netherlands, France, Czech Republic, Germany and Belgium.

But today I had a great idea. To celebrate nearly two years, and sales of more than 2,000 copies, of my book “Stealth Antennas” I'm going to switch to my indoor parallel-fed dipoles or MFJ-1786 magnetic loop, turn the power down to 5W and work QRP with the call.

I'll try and operate around +/3 KHz of the CW QRP calling frequencies on 40, 20, 17, 20, 15 and 10m.

I plan to try and do this at least once or twice a week and I'll add the times/bands of operation to the top of this story each time.

This idea was inspired by John N8ZYA in Charleston West Virginia, who is featured in the book and works stations using Isotron antennas mounted indoors. And yes, he does work lots of DX!

Be good to work you.

Steve G0KYA 

Update 6/8/12
Well, great evening. Condx not too good and lots of noise/QSB but worked: RY7G, OH2NOS (10W his end), OM3CAZ, OM8RA, R6AF, HA5AEK, IT9BUA (QRP), EA8AGF (QRP), S51WO (17m) and the highlight - Taka JA0FVU (17m), otherwise all on 20m QRP 5W from an Icom 756 PRO 3. Using a new touch keyer so a few mistakes! Mostly used the outdoor 20m M0CVO Windom (OCF). One or two were with indoor dipole, but needed a little more oomph. Will be on the air again soon.

Update 16/8/12
Had another session with the Olympic call today and worked R10RLHA/1 (Russian Lighthouse), RN3DMU, UA4NE/P, R200V,HG20SD, CT3AS, 5N7M (Nigeria), EW8O and OM3KFF. A couple were on 5W, but the majority on 50W. I have put the Western HF10 dipole back up in place of the M0CVO Windom as I had to repair the 10m fishing pole support - works well on 20m. Not so sure about 15m though! Very pleased about Japan and Nigeria.
 

UK propagation charts for August 2012

It may be summer, and the Olympics are in full swing, but we can’t really expect to see record-breaking propagation on the HF bands in the Northern hemisphere.

This often puzzles new (and not so new) hams. After all, HF propagation relies on sunlight and we have that in abundance in the summer.

Unfortunately, life is not that simple. While increased UV in the summer is guaranteed, as the angle the sun makes with the ionosphere in the northern hemisphere is increased, you actually get less overall ionisation of the all-important F2 layer.

This is due to a chemical change in the composition of the F2 layer in the summer compared with the winter.

There is an increase in the molecular-to-atomic composition of this layer in the summer, which makes it harder to ionise. As a result the F2 critical frequencies in June can be half what it they are in January.

This effect is called the Winter Anomaly.

At the same time D-layer absorption is very high in the summer, especially around local noon, which gives us a double whammy – lots of absorption and low F2 critical frequencies.

The net effect is that the bands much above 18MHz can remain stubbornly closed, apart from Sporadic E (Es) openings, which by August are less prevalent. And the lower bands are also less useful during the day due to absorption.

For this reason stay away from 80m (3.5MHz) in the daytime – 40m will be better around the UK as long as the critical frequency stays up near 7MHz. Twenty metres (14MHz) will probably remain the most reliable DX band both during the day and night, although don’t write off 18MHz (17m).

Better HF conditions will start to reappear in September – sunspots, solar flares and coronal mass ejections (CMEs) willing.

Don’t forget there is a free book about HF propagation available to download on the right.


Go to the August propagation charts from the UK

UK propagation charts for July 2012

There is an old Chinese curse that says "May you live in interesting times". I thought it was a greeting, but apparently not!

Well, we are living in interesting times as far as HF propagation goes.

July is usually in the middle of the HF summer doldrums - not really good conditions to speak off, but with some Sporadic E (Es). But this month is being characterised by a mass of solar flares, coronal mass ejections (CMEs) and high solar flux index (SFI) levels.

So while high SFI numbers usually indicate good conditions on the upper bands, the flare actvity is causing havoc with the bands shut down and lots of noise. Couple this with summer thunderstorms (Medium Wave was just a wall of crashes and bangs on Thursday 28th June) and it is hard to know what to work.

But in amongst all this there are good openings to be had. On 4th July I worked K2K in New Hampshire on 15m CW. This was a station being run for the US Independence Day and the prop charts would suggest that no path would have been open on that band and at that time ((1415hrs GMT).

Others are chasing 1A0C - The Order of Malta’s Italian Relief Corps (CISOM)- which is in Rome, not Malta by the way. Its signals have ranged from barely audible to S9+ depending on the solar flares and CMEs.

The best advice is keep on eye on the solar data at www.solarcycle24.com, and don't write the bands off too soon. And if you don't know what SFI, A and K indices are, take a look at the free HF Propagation book listed on the right.

73 and gud DX! Steve G0KYA

Go to the July propagation charts from the UK

or select another month