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 http://www.youtube.com/watch?v=Z41FLKaT7eY and
http://www.youtube.com/watch?v=C8ZRW0q6SyI

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: http://gx4crc.com/gb4imd/

Friday, 4 March 2016

Working the International Space Station with 2m APRS

The proof - G0KYA works RS0ISS as shown
at www.ariss.net, 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 http://www.ariss.net/ and this will also plot your location on a map. You can get the details of how you apply for a QSL card at: http://www.ariss-eu.org/traffic/european-qsl-bureau

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 www.qsl.net/on7eq/en/index.htm

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 http://uz7.ho.ua/packetradio.htm

2. Download and install UISS from http://users.belgacom.net/hamradio/uiss.htm

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 http://www.cantab.net/users/john.wiseman/Documents/CAT7200.html and download the file CAT7200.zip. 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 http://amsat-uk.org/beginners/how-to-work-the-iss-on-aprs-packet-radio/








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.








Friday, 12 February 2016

Radio Norfolk interview about Tim Peake and ISS

ESA astronaut Tim Peake.
I was lucky enough to hear astronaut Tim Peake's ISS contact with another UK school on Thursday 11th February 2016.

Not only did I record it, but I sent out a press release and ended up being interviewed about it by BBC Radio Norfolk.

The Norfolk Amateur Radio Club had put on a workshop the next day at the City of Norwich School for students who are going to be involved in their contact with Tim in two weeks, so it was very fortuitous.

You can hear the ISS downlink on 145.800MHz and you don't need a particularly fancy antenna.

If you do hear and record Tim do contact your local media as they are fascinated by the whole business and it brings good PR for amateur radio in general.

Anyway, here is the audio from Radio Norfolk in MP3 format.



Saturday, 9 January 2016

HF Propagation charts for the UK updated

I've now updated my propagation prediction charts for the UK through to April 2016.

See http://www.infotechcomms.net/propcharts/

I've used the latest smoothed sunspot numbers from NOAA in the US. There is little point in updating them much further than four months as the SSNs change, and it takes me about three hours to do four month's worth of charts and upload them - that's a chart for every hour and for every band or 24 x 8=192 charts per month.

It is interesting to see how the solar cycle is falling away. In January 2015 the SSN was 62, now it is just 45. The coming months will see further falls.

This means that we will see fewer openings on 12m and 10m, but 15m should still open up at times. I worked the US Virgin islands on 15m CW this morning and it was open to the eastern seaboard of the US this afternoon so don't write it off.

The new
web based version of ITURHFPROP
The RSGB Propagation Studies Committee, of which I am the chair, is also working on a new online HF prediction system based on the ITU program ITURHFPROP.

This uses a different, but newer, ionospheric model to the VOACAP engine normally used, but the original ITURHFPROP software is not very easy to use.

But thanks to the work of Gwyn Williams (G4FKH), James Watson (HZ1JW) and Chris Behm we are getting closer to a web-based version. You can try the test model at http://www.predtest.uk/

Ultimately, it will have the ability to produce point to point predictions as well, just like VOACAP Online. But lets learn to walk before we run.

It will be interesting to compare the two models and Gwyn would welcome any feedback. His email details are on the web page for the new model