Monday 30 September 2013

2013 National Hamfest

As a newly licensed amateur I was looking forward to this year’s National Hamfest and had an enjoyable time with my brother and both of us spent some money, but nothing too extravagant.

As well as the normal plugs/adapters I splashed out on a huge tube of thermal compound to hopefully have another go at getting an old laptop working again. I got a second Baofeng UV-5R+ handheld and a Nagoya NA-771 dual-band whip from Handyradio. A large magmount and a stupidly big 2m/70cm dual-band antenna for mobile use from Moonraker! In retrospect I perhaps should have gone for something a bit less conspicuous but wanted something with a bit of gain and it was only £15! A cheap and cheerful power-swr meter from Waters & Stanton and finally the 2014 RSGB yearbook (with a free goodie bag) completed my purchases.

This was the fourth year of attending and this year I did find it slightly disappointing compared to previous years maybe it was because I went with the silly notion of picking up a decent HF and/or VHF/UHF all-modes transceiver for next to nothing. Doh!

 
There was plenty of second-hand equipment both in the hall and in the car-boot sale outside but most of looked like junk and seemed overpriced. I am sure there were bargains to be had but being a newcomer I am not skilled or confident enough yet to take the risk.

The RSGB bookshop seemed to have a smaller range of  titles available than previous years and they didn’t have the one book I wanted to peruse before deciding whether to purchase it.

The usual main dealers were there and this year there seemed to be more show deals, I noticed on the Moonraker stand most of their products were marked down from the usual list price. Not massive savings but enough to sway me to make some purchases.

I was very tempted by the Yaesu FT-857D that was for sale on the ML&S stand for £619 but I think it will have to wait for a few months (years) to replenish my funds before making the investment. Though we did get free hats from the Yaesu stand!

My baby brother enjoying his Double Decker

I did manage to meet up with Nigel and Andy from M0CVO antennas, Nigel is also the chairman of SKARS a local club and I hope to attend one of their meetings very soon, especially as they are planning some HAB launches of their own.

From my naive point of view it would be nice if the Hamfest was a little less about selling things and had more information about special interest groups and activities. Maybe that is the function of other events such as the RSGB Convention and the various conferences but the interest groups and information points there were seemed scattered around the hall. For instance the first year I attended I also signed up for the Group for Earth Observation (GEO) group.

Don't misunderstand that is just a minor gripe, the Hamfest being on the doorstep it was still a great way to spend the day, next year I plan to attend on the Friday rather than the Saturday something tells me there may be more bargains to be had then.

Friday 27 September 2013

APRS IGate - "If you build it they will come"

The 2013 National Hamfest is taking place this weekend, it is held over two days at the nearby Newark Showground. I will be visiting tomorrow (Saturday) as work commitments prevent me attending today, so no doubt all the best second hand bargains will be gone!

Seriously I am looking forward to it now that I am a proper licenced radio amateur. The Hamfest has been held at this venue for several years and always gives me the opportunity to hear the VHF/UHF bands full of local chatter. Normally the chatter consists of operators trying to give each other directions! The showground isn’t very well sign posted from the local approaches.

In previous years they have a had a call-in station operating on the usual channel (S22) 145.550MHz, but today it wasn’t in evidence well not at 10:00am when I listened in, instead there were several local operators chin-wagging with the occasional calls asking for the rally call-in.


This year the Hamfest have enlisted the services of the BritishAmateur Television Club to give live internet television feeds. Go to the live eventspage and there are two streams and currently a third from GX3RCM available.

One thing I hinted at previously was to experiment with APRS and I really wanted to get an APRS IGate set up in time for the weekend as I was expecting a number of the attendees at the Hamfest would be using it.

From the Wikipedia page 
"Automatic Packet Reporting System (APRS) is an amateur-radio based system for real time tactical digital communications of information of immediate value in the local area. In addition, all such data is ingested into the APRS Internet System (APRS-IS) and distributed globally for ubiquitous and immediate access. Along with messages, alerts, announcements and bulletins, the most visible aspect of APRS is its map display. Anyone may place any object or information on his or her map, and it is distributed to all maps of all users in the local RF network or monitoring the area via the Internet. Any station, radio or object that has an attached GPS is automatically tracked. Other prominent map features are weather stations, alerts and objects and other map-related amateur radio volunteer activities including search and rescue and signal direction finding."

There are two short video on youtube which describe the APRS system and the role of IGates, an IGate is basically a receiver station that puts locally received messages into the APRS-IS system.



I have a Baofeng UV-3R handheld transceiver which I have pressed into service. I don’t have a dedicated TNC so am using the compute sound card to receive and send audio to the transceiver via the handset connector and am using the AGWPE as a software modem/TNC that is used by the APRSISCE/32 client to create the station.

It should have been straightforward as I already had an eQSO interface which should have provided an isolated audio interface and control of the PTT on the UV-3R, all I had to do was create a suitable connecting lead.

During the commissioning the station seemed more than capable of transmitting messages but it wasn’t receiving anything, checking the audio coming in to the PC and I was getting virtually nothing! The interface was dismantled and the signal scoped. Oddly it seemed the UV-3R really didn’t like the isolating audio transformer and this seemed to shorting the output from the transceiver, so now at present it is just directly connected.

Sadly while using the scope to see the signal the ageing scope decided to commit suicide in a loud bang and cloud of acrid smoke, oddly despite the pyrotechnics it was still working till I turned if off and now it won’t turn on! I suspect a capacitor in the switch mode supply has died in spectacular fashion.

Anyway I digress, having got the system working properly late last night it is currently running and has indeed received a number of stations this morning as made their way to the Hamfest.

The UV-3R probably isn’t the best choice as a receiver as its audio is pretty dreadful but it seems to work, it is connected to a generic X-50 antenna stuck on the top of a 4 meter pole. The pole is in fact a 5 meter telescopic painting pole costing less than £16 from B&Q.

I haven’t fully extended the sections as the joints could be potentially weak, but it is anchored to a metal fencing pole and then with three guy ropes it seems sturdy and has stood out all week, just lowered down slightly when not in use.

X-50 in the garden
You can see a map of the current APRS stations at http://aprs.fi my station statistics can be seen here http://aprs.fi/info/a/M6GTG

This was a snapshot of the map earlier showing the cluster of stations at the showground


Quite a few operators are using their smartphones rather than radios to update their position. I have installed APRSdroid on my phone (not free from Google Market, for free version go to developer website see Pete's 2E0SQL comment below, and you need to be a licenced amateur with a valid passcode) but it gives me a warm feeling to know my humble set up has allowed some people to show up at their destination using their 'proper' radios.

The shack - APRS setup on the left hand side

Monday 23 September 2013

My seemingly magic HAB antenna

Since visiting the UKHAS Conference and getting my Foundation licence I have come of out of my lull with a new found buzz and have been busy with my radio gear.

I have helped track a few more High Altitude Balloon (HAB) flights, uploading the received telemetry data to the Habhub server. Visit the UKHAS website for more information on how to become involved.

I am still surprised by the performance of the loft antenna I am using to receive the HAB telemetry. It was constructed as an experimental wide band antenna solution to use with my scanners back in 2007. I discovered some basic plans on the internet for this simple home brew antenna (originally hosted on a Geocities website, but is thankfully archived on Reocities here)

It is a modified bicone design and is constructed from nothing more than a couple of metal coat hangers fixed to a piece of pvc water pipe, with a 10m length of RG58 coax as the feeder. I used it successfully as a portable solution, mainly for airband listening and stuck it on top of a fibreglass fishing/flag pole when camping away at dog agility shows as these photos show.



Eventually it ended up being mounted up in the loft, suspended on a piece of string from the rafters and had largely been unused since I acquired a discone a few years ago.

When I first started tracking the HAB payloads I naturally used the discone but soon became frustrated by its variable performance and so tried this antenna instead and was amazed. Something appears to be just right with this antenna on 434MHz when used together with my FUNCube Dongle PRO+

I haven't analysed why is seems to have such a sweet-spot on these frequencies and I am not touching it, moving it or even taking another picture of it in case it loses it's magic properties! Remember these HAB flights are only 10mW and this antenna is under a slate roof!

On Friday (20-Sept-2013) Adam Cudworth (@adamcudworth) launched HABE-10 which involved a normal tracker on the balloon due to burst at around 35km along with a secondary tracker payload of a 3D-printed man that was separated at approx 27km, the two payloads being tracked separately as they fell to Earth. During the accent the main tracker also transmitted SSDV images from an on-board camera. Unfortunately this failed during the mission but some pictures were received before it did, as you can see I managed to successfully receive this 300 baud RTTY signal from home and uploaded packets to help reconstruct the images. The original images are at http://ssdv.habhub.org/HABE/2013-09-20





 

 


Friday afternoon also saw the launch of Leo Bodnar's B-13 pico floater. Leo has become something of a HAB superstar following his amazing B-11 and B-12 balloons which broke the duration record for an amateur balloons (as reported on the Southgate ARC website) flying over many countries before contact was lost.

Sunday saw a launch of MOD-1 by Ugi, which again I received rather well as can be seen on this pie chart.


Today saw Steve Randall (G8KHW) launch two of his XABEN flights, XABEN-56 and XABEN-57. The main transmitters were on 434.250MHz and 434.300MHz and I was able to use the multiple VFO option of SDR-Radio.com V2 to track both launches, and as you can see from these pie-charts I made number three in the tracking charts! I achieved this while using a VNC connection to control the receiving station from work, just checking occasionally to correct for any drift in the frequency of the signal caused by the temperature variation of the transmitters.






Tuesday 17 September 2013

CQ CQ this is M6GTG calling CQ

I was alerted this morning to the news that some of my fellow Foundation candidates had received their notification from the RSGB this morning and had claimed their call signs.

So I rushed home at lunchtime, grabbed the post off the doormat and was excited by the only large white envelope with my name on! Ripped it open to find out I had been specially selected for an American Express Gold Card.... I swore rather loudly!

I couldn't wait another day so rang the RSGB Examinations department and the nice lady there informed me it had been sent out yesterday and Ofcom had been sent the information but kindly gave me the candidate number I needed to log on to the Ofcom website to claim my licence... 

Five minutes later I had my callsign

M6GTG

Mike-Six-Golf-Tango-Golf has a nice ring to it, and I chose it to celebrate my late Father (his initials) it was he who encouraged me and made many sacrifices, including no end of electronic devices which I invariably dismantled on my way to becoming a nerd!


Oh that is me on the left ;-)


Sunday 15 September 2013

Still waiting! But did get a new toy

Everyday last week I have picked up the newly delivered post with growing anticipation only to be disappointed. I am still waiting for the official notification of my foundation pass from the RSGB so I can apply for my call sign. They do say it can take six days from when they receive the tests, so hopefully it will be early this week.

Something did turn up in the post on Saturday morning, I was awoken at 7:30am by a knock on the door, bleary eyed I took delivery of my latest purchase from eBay, a Baofeng UV-5R+ handheld. This is a Chinese made VHF/UHF dual-band FM transceiver suitable for the 2 metre and 70cm bands. The package came with an official Baofeng USB programming lead and a small handheld speaker/microphone that can be plugged into the main unit all for the pricely sum of £37 including postage.


I can admit now to already owning a Baofeng UV-3R which I have had for some time but have only ever used for receiving and the odd transmission on the PMR446 band. It cost about the same price and considered it a bargain then but on first impressions the UV-5R+ seems even more of one. It is a much more substantial device, it feels very solid in the hand. The display is bright and clear and the proper volume control and keypad make for a more pleasant experience, you can actually turn it down unlike the UV-3R which is deafening or off! It came with a proper drop in charger, a USB programming lead and a small hand-held speaker/microphone/PTT unit.

These units are just stop gaps until I get around to getting a decent amateur rig, the current front runner being the Yaesu FT-857D which is a nice small affordable(ish) unit giving me all-modes on HF and VHF/UHF. The 2013 National Hamfest which takes place in couple of weeks, right on my doorstep, could be a dangerous place for my credit card!

As well as having a chinwag I have already got a plans for a project to investigate APRS. I am hoping to use an old echolink/eQSO interface I built, around 10 years ago, linked to the UV-3R and a computer sound card. I am still investigating it but it seems the software which will be AGWPE to act as a TNC driven by the APRSISCE/32 the Amateur Radio client for windows.

I am especially looking forward to trying to contact the digi-repeater on board the International Space Station, some details here.   

Monday 9 September 2013

Foundation Passed! - International UKHAB Conference 2013

Picture courtesy of Steve Smith G0TDJ

It doesn't happen very often but someone took a picture of me looking happy! (I am the big guy on the left struggling to smile, my face muscles have obviously atrophied)

The six of us had just successfully completed and passed the Foundation Exam and Practical course held as part of the International UKHAB Conference 2013. Now am just waiting for the official notification in the post so I can go on-line to claim my M6 call sign.

Over the last six months I have become a keen tracker of High Altitude Balloons (HAB) released by a motley crew of enthusiasts. It is a multi-skilled fascinating hobby involving electronics, embedded system programming, radio as well as some Blue Peter art and craft skills to construct the payload.

I wish to become more actively involved so decided to attended the conference held this weekend at the University of Greenwich. After booking my ticket I learned the organisers were planning to hold an Amateur Radio Foundation Practical Course and Exam and so jumped at the chance as I could finally get my licence. My previous attempts having been scuppered by apathy, shyness and circumstance.

Picture courtesy of Steve Smith G0TDJ

The conference consisted of a number of talks and discussions followed by a number of demonstrations and workshops, while the demonstrations and workshops were taking place we went away to do the practical assessments and the exam. I would have loved to sit in on some of the workshops but you can't have everything and there is always next year.

There was some interesting talks including a talk by James Coxon who took a look back at the early days of High Altitude Ballooning, John Graham-Cumming gave a humorous and painfully accurate talk on software debugging, one highlight being when the presentation froze on a picture of Don Johnson in his Miami Vice days (it was an Adobe pdf need I say more!)

Other talks included Matt Brezja on Forward Error Correction and how it could be implemented to improve tracking with low-power transmissions. Making the conference truly international were Ara Kourchians on Environmental Testing, Design, Analysis for HABs as well as Alain Verbrugge (F6AGV) who gave a talk mostly in French on ideas for controlling solar balloon flights, however it was fascinating and informative thanks to an impromptu volunteer translator from the audience as well as James Coxon and some other French speakers assisting.

The conference was filmed and streamed by the BATC and some of the talks can be viewed on their website and can be viewed here select the "HAB 2013" archive and then the desired presentation from the drop down menu.

Despite my almost chronic shyness I got to chat to quite a few people including Steve Smith G0TDJ who took the picture above and has given me permission to use it. I even went down the pub and had a quick pint before setting off back home.


Down the pub


The venue itself was very impressive, got to admire the historic buildings and the restored Cutty Sark walking to a from the train station. London transport was flawless including the impressive Docklands Light Railway (DLR) it was a brilliant if tiring day.

The Venue - Old Royal Naval College
 
The day draws to an end at the Cutty Sark

I would like to say a big thank you to Anthony Stirk (M0UPU) and James Coxon for organising the event and Philip Crump (M0DNY) and Mike for holding the practical course as well David Akerman (M6RPI) and Phil Heron for invigilating the exam, we even had a visit from the RSGB inspectors.