Friday, 22 December 2017

Radio Caroline back on Medium Wave

The Orford Ness masts
If you fancy a bit of nostalgia you can now listen to Radio Caroline again on 648kHz AM on the medium wave.

The famous pirate radio station needs little introduction, but is now broadcasting legally using (ironically) the famous Orford Ness antenna system on the Suffolk cost, formerly used to transmit the BBC World Service in English around the clock on 648 kHz from September 1982 until March 2011.

The station was founded in 1964 to play pop music all day at a time where broadcasting was dominated by the BBC and pop was played for an hour a week.

Caroline was one of five stations granted a community radio licence by Ofcom and is now running 1kW, but with a really good antenna mounted right next to the sea.

The station is 59+20dB at my home QTH 10 miles south of Norwich (JO02NN) using a Perseus SDR and a homemade 1m active loop mounted in the loft. It is also easily heard with a portable radio.

Radio enthusiasts around Europe might like to listen for it.

More information:

Orford Ness transmitter:
https://en.wikipedia.org/wiki/Orfordness_transmitting_station

Radio Caroline:
http://www.radiocaroline.co.uk/



-->

Friday, 15 December 2017

Propagation prediction maps updated until June 2018

I have now updated my propagation maps with the latest predicted smoothed sunspot numbers for the period up until the end of June 2018.

You can access them using this link.

The sunspot numbers continue to fall as we head towards sunspot minimum sometime around 2019.

If you use the charts look for about 60-70% reliability for SSB (yellow or hotter) and perhaps 40-50% for CW or PSK (green). For FT8 you may be able to work stations where the reliability is down to 20-30% (blue).

Of course, these are a guide and if you want to try making charts for your own station I recommend the online software at either voacap.com or www.predtest.uk/


Tuesday, 21 November 2017

Christmas present ideas!

As Christmas is coming, I thought I would remind people that there are some great radio-related goodies for sale at CafePress.co.uk and .com.

You can choose from a number of items, including:

  • Three different types of ship's radio room clock, with silent period sectors marked
  • "Remember QRT SP" Merchant Navy Radio Officer merchandise
  • "Keep Calm and Work Some DX" merchandise
  • "Keep Calm and Work Some CW" items
  • Nikola Tesla merchandise, featuring him sitting in his Colorado Springs laboratory in 1899, surrounded by electrical arcs.

You can have the last three slogans added to T-shirts, sweatshirts, mouse mats, calendar, mugs and much more.

Just go to the Radio Room!

Or there are a number of my radio-related books that make good presents , including "Radio Propagation Explained", "Antenna Modelling", "Stealth Antennas" and "Getting Started in Amateur Radio". Use the image links on the right for more information.

Thursday, 12 October 2017

HF Propagation at Sunspot Minimum

The effects of coronal holes are likely to continue for a
couple of years.
This weekend I’ll be giving a talk at the RSGB conference on “HF Propagation at Sunspot Minimum.”

This will show that we can expect the minimum to be around late 2019 or 2020. It is hard to be precise, as the minimum is something you can define after the event, not before or during!

What I will say is that we can probably expect the effects of solar coronal holes to continue, at least until we are well into the minimum.

Geomagnetic storms can cause problems on HF, although they can also bring short-lived ionospheric enhancements so they are a double-edged sword.

For example, on Tuesday 10th October the bands were open to DX all the way up to 12 metres. But as the solar wind from the coronal hole hit on Wednesday, apart from a short-lived ionospheric enhancement the MUFs took a dive.

By Thursday (12th) lunchtime, 20m was struggling to fully open and 17m was showing very little activity indeed. But by Thursday afternoon, and with a K of 5,  I had worked Saudi Arabia on 10m SSB.

This shows that at sunspot minimum with a solar flux index of just 66, quiet geomagnetic conditions may be better than stormy ones. So look for a K index in three 0-2 range, not 5-7! But then again, when solar plasma first hits the earth we may get some short-lived enhancements right up to 10m, so a high initial K index can work for us.

For those who weren't at the lecture, I showed that monthly average maximum useable frequencies will decline with the sunspot number. This doesn't mean there won't be F2-layer openings on 21MHz and higher, just that they won't be as reliable or as long lasting.

Other than that I encourage people to play with a propagation program to get an idea of what might be possible.

My suggestions are:

Windows based

VOAProp

HAMcap

W6ELProp (when installing, right click and run as administrator on Windows 10)

VOACAP


Online

VOACAP.com

Predtest.uk


Other sources of info I mention are:

Solarham.com

NOAA – Space Weather Prediction Centre

Real-time F2 critical frequency display (this will soon move to Propquest.co.uk)

Smoothed Sunspot Numbers

Latest extreme UV image of the sun from the Solar Dynamics Observatory spacecraft (shows coronal holes)

Lastly, I talk about the difficulties of predicting openings with FT8. One suggestion is to use VOACAP and set the required SNR to a figure of -20dB or so. It is usually set to about 24-31dB for CW and 45 for SSB. This is still experimental (as some SNR figures are quoted as dB per Hz, while others are quoted in a 2500Hz bandwidth), so you might have to play with it. VOACAP’s settings are critical and it is worth reading the notes on the VOACAP website and also the “Top 10 mistakes in using VOACAP”.

Sunday, 24 September 2017

Visit to NI6BB, USS Iowa, San Pedro, California

The big guns of the USS Iowa.
As many regular readers of this blog may know, I try to visit as many special amateur radio stations as I can when working overseas.

This week I am in Long Beach, California again for a conference and it was an ideal opportunity to visit the famous battleship USS Iowa in nearby San Pedro, which has an amateur radio station with the callsign NI6BB.

USS Iowa (BB-61) is a floating maritime museum that is well worth the visit. It has a rich history that spreads from World War Two, through the Korean conflict in the 50s, and the cold war before it finally became a museum in 2012.

US Navy veteran Jerry Johnson with
one of the 110lb powder sacks.
Its main battery consisted of nine 16 in (406 mm) Mark 7 guns, which could fire 2,700 lb (1,200 kg) armour-piercing shells 23 miles (37 km). On the tour you find out how they used to load the guns with six 110lb silk sacks filled with powder, which when ignited with a single cartridge would rapidly burn in one third of a second, firing the 1,900 lb (862 kg) shell out at 2,690 feet per second (820 m/s).

The USS Iowa discone-cage HF antenna,
complete with plastic owl!
The other statistics are staggering (including 19.7-inch armour plating), but I’ll leave you to Google them.

Anyway, back to the radio, the radio room on the Iowa is well equipped with a Kenwood radio for HF.

On the bow of Iowa is the discone-cage antenna. Fed at the top it is a discone providing coverage from approximately 10 to 30 MHz with a VSWR below 3:1. The antenna has a plastic owl on it to stop pigeons resting - but they ignore it apparently!

Ron Frank N3HI let me operate some 20m SSB from the ship, as I have G0KYA/AB8ZV UK full and US Extra Class licences, and I worked a few stations including Washington State and Ohio. One was a “nearly” as I couldn’t quite get his full call before he faded away, which was a shame. HF conditions weren’t brilliant.

There were one or two loud stations on CW, which they often work, and Ron says they tend to operate a lot of digital too, including FT8.

Anyway, my thanks to Ron for letting me play for an hour and giving me some detailed history of the USS Iowa. If you are ever in the Long Beach/San Pedro area go and visit. It is truly fantastic.

My thanks to Ron Frank, N3HI.
I also revisited W6RO, "The Queen Mary", in Long Beach, California where I am staying. I operated from there in 2012 and they always welcome visiting radio amateurs. We had a long chat about UK and US amateur radio.

If you are interested in some of my other historic radio visits you can read about:
  • NI6IW - USS Midway, San Diego, California
  • W7SUB - the USS Blueback, Portland, Oregon
  • K6KPH - The Maritime Radio Historical Society, Point Reyes/Bolinas, California

Saturday, 9 September 2017

Elecraft K1 discontinued

Elecraft has announced that it has discontinued the K1 transceiver. I'm not surprised as this had been predicted some time back.

Component availability had been an issue, and technology has moved on.

Luckily, a local ham managed to get one of the last K1s after reading about them - and seeing this blog.

I'd like to thank Elecraft for producing a great little radio and for supporting QRP. There's always the KX2 and KX3!

Thursday, 6 July 2017

CW fun with the Elecraft K1

I haven’t had much of a chance to get on the radio recently – the day job has been getting in the way!

So I thought I would put my Elecraft K1 into action yesterday evening and see what could be done with 5W of CW. I built this rig last year after having the kit in the loft for about 12 years – you can read about that here.

The great thing is it only has two bands 20m and 40m. This focuses the mind and stops you QSYing to other bands left right and centre.

So, I hooked up to a W5GI dipole and a 65ft EFHW (with loading coil for 80m too) and switched on.

The first station worked was OZ7BQ, Joe near Copenhagen, on 7.026MHz. I had to double check his name as it shows on QRZ.com as Hans Jørgen, although he definitely sent “Joe”.

Then it was IQ7AF on 7.028MHz, a special event station in Southern Italy.

Joe OZ7BQ
Staying on 40m, I narrowly missed Mike GM0HCQ/MM on the James Clark Ross, a research ship just off the coast of Norway and heading for the Arctic.

Then it was on to II2FIST on 20m, celebrating 30 years of the FISTS CW group. Managed that on first call despite a pile-up – not bad with 5W.

And to round the evening off I made contact with Doug ZP6CW in Paraguay on 20m. Other countries heard but not working included Norway, Serbia, Germany, Russia and Czech Republic.

This isn’t to brag, just to show what you can do with 5W CW from a kit-built rig and a compromise antenna. All the 40m contacts were on the home-made W5GI dipole. Half of the 20m ones were with the multi-band EFHW.

I think 5W SSB would have been a different story.