Monday 22 September 2014

NI6IW, USS Midway, San Diego

I was lucky enough to visit the USS Midway aircraft carrier in San Diego, California, last week while on a work trip.

It is now a floating museum, dedicated to telling the story of how an aircraft carrier functioned, with a lot of the stories told by ex-Navy personnel who served on it.

I was even more lucky because Hal KI2HAL gave me a behind the scenes tour of the ship's amateur radio station NI6IW.

It has three Elecraft K3s that allow it to work all bands. Because of the museum's rules, all the antennas have to be the original authentic models fitted to the ship when it was in service. This means that the ham station uses a couple of navy verticals and a sloping three-wire set-up.

I was able to tune one of the verticals for 17m to see if I could work the UK – a distance of more than 5,000 miles. I didn't make contact, although I think I did hear G3SGE on CW working a CT station. I've not been able to track down who G3SGE is though.

The ship also has an Icom D-star set-up and makes a lot of contacts that way.

The ship is active on the Museum Ships weekend "on the air" days so you might be lucky to hear it.

The antennas
In all, the ship is fascinating – you can hear from a retired Navy pilot exactly how you land and take off on an aircraft carrier. Hairy stuff.

My thanks to Hal for showing me around. Just click on an image above to see a bigger one.

Thursday 11 September 2014

Signs of 10m opening up again for Autumn

In September, 10m propagation from the UK generally favours
north-south paths.
Nice to see 10m starting to open up again this Autumn. With the solar flux index (SFI) at around 160, I was testing a new antenna yesterday and heard 3B9FR (Robert) on Rodriquez Island in the Indian Ocean.

I bagged him first call on CW and thought it might be an opportunity to see what else was on. Two minutes later I had the ARRL centenary station W1AW/5 in the log from Texas on 10m.

I also heard low-power 10m beacons from Florida, Alabama and New Hampshire. Luckily, I heard all this before the X class solar flare hit us at 17:45UTC. The associated coronal mass ejection (CME) will no doubt cause us problems in the next 24-48 hours.

It is a little early in the season for the Northern USA on 10 metres to be reliable (see my prediction charts), but it bodes well.

In view of the date today, it did remind me of that fateful “9/11” back in 2001. On that day the SFI was 250 and I was working in my shack in the UK listening to the KQ2H repeater in New York on 29.620MHz, I heard the whole scenario played out.

From the first conversations suggesting that a Cessna had crashed into the WTC, to the full horror some time later. Eventually all communications ceased – I only found out later than the repeater was actually on top of the WTC itself, which explains why it went off the air.

Nowadays KQ2H is still on 29.620MHz, but is located in the Catskill mountains of up state New York. When conditions are right it is very loud indeed and a great indicator of good 10m propagation into the USA. I expect we will be hearing more of KQ2H in the UK over the next month or so.

This is a good time to prepare for worldwide 10m openings in the coming months. Don't miss them!

Tuesday 2 September 2014

Steve Weber KD1JV's MTR three-band QRP radio

I finally finished my new HF QRP toy and it works a treat. I put my name down for the latest Mountain Topper Radio (MTR) design from Steve Weber KD1JV a few months back. Steve only releases a limited number of his designs each time and I was lucky enough to get one.

The finished three-bad MTR QRP rig.
Steve's radios are legendary and include the ATS-3/ATS-4 and derivatives.

The latest MTR is a three-band 2.5-3W QRP transceiver that can be built for 40m, 30m and 20/17m. It can even be persuaded to go onto 80m apparently. It is very advanced with a built-in keyer, memory, attenuator, single character digital readout, Morse annunciation and much more.

The best thing is it is tiny – about the size of a pack of playing cards.

I attended the G-QRPconvention last October and was inspired by some of the tiny QRP radios people had there, especially Colin M1BUU who had some rigs that were real works of art.

I held fire on building it for a couple of months to see if there were any changes to the instructions. As it was, Steve had to send out another chip as the original keying algorithm wasn't quite right.

So, with new chip in one hand and a very fine-tipped temperature-controlled soldering iron in the other I tentatively set about the build.

First off, this isn't one for beginners. It is about 90% SMD and the parts are tiny. Having learned my lesson the hard way I used a large baking tray to work on in an effort to stop parts flying off, never to be seen again. As it was I did loose one part for a few hours but eventually found it in the carpet. With components just 1-2mm in length this kit is not to be sneezed at – or over!

I took my time, spreading the build over five three-hour sessions. Apart from putting three capacitors in the wrong place (which I was able to retrieve) it went together quite well. On power up it received first time and I was able to go through the set-up routines with no bother, using a PC with PSK31 software to set up the oscillator on 10MHz as instructed.

But then it wouldn't transmit any RF. I eventually tracked it down to a poor joint on the L18 output toroid – I hadn't got all the enamel off one of the leads.

Bear in mind that this board is only 8.5cm wide.
I managed to get 3.5W out on 40m and 4W on 30m with a 10.1V pack of eight Ni-Mh batteries. On 20m I got about 3W. After glueing the cores to the board to make the whole structure more rigid I found that other people have said you can probably get another Watt out on 20m by removing a turn from the two 20m toroids.

Adopting the “if it ain't broke don't fix it” methodology I'm happy with 3W!

Incidentally, when I took the photograph of the board I noticed that there was a stray filament of wire laying on a chip. This must have come from when I was doing the final wiring. I've now removed it, but it goes to show how a digital camera can be a Godsend with SMD construction.

So does it work? Oh yes!

My first outing on 40m at home brought back Gunner OZ6NF in Copenhagen who gave me a 559. Next up was Pascal F5UQE in Lille who gave me 589.

I think this is an excellent fun radio and ideal for backpacking – if only we had some mountains around. The nearest big hill is 150 miles away from here!

So how do you get your hands on a Steve Weber designed radio? First you have to join the “AT_Sprint” Yahoo Group. That's where Steve announces that he is going to make a quantity of kits. Secondly, when he announces that this is going to happen you send him an email. If you are then lucky you will be selected and have to pay via PayPal. Good luck – the interest level is very high.

Overall, it is a fantastic design and well worth making.

73 de Steve G0KYA

Update 3/9/14; Tried it out on 20m today and worked Switzerland, Spain and Belarus. Went back to 40m and worked Moscow. Sensitivity is pretty good - not quite an Icom 756 Pro3, but look how big it is! Lots of fun.