Wednesday, 18 December 2013

Mentioned in Practical Wireless! and some Christmas stress

I am not a fan of this time of the year. I know Christmas is supposed to be a time for joy and a time for families to re-connect and come together. Well this year it is true, the only problem is they are all coming here for Christmas day, night and Boxing day!

This has meant I have had to tackle some long put off home renovation projects. The first was to redecorate the bathroom and what should have been a simple paint job has snowballed into a major project and has sapped a lot of free time. Thankfully it is now all but done.

The second was to turn the third bedroom back into an actual bedroom rather than the study/computer room/indoor radio shack it had become. Again this involved more work than planned including dismantling and remodelling of a home-made desk and the removal of piles of collected radio/computer junk and books.

The upshot of all this work and de-cluttering is my outside workshop has turned into a bomb site! Most of the junk has been dumped in it and it is very untidy with tools scattered everywhere. I also had a minor catastrophe when trying to retreive a workmate when my beloved 2Meter YAGI, fell off its perch breaking off the reflector and a director! Thankfully Justin at InnovAntennas was able to sort me out some replacement boom insulators

With all this upheaval, combined with work pressures I have been unable to really do any radio or electronics for most of this month. Do I sound like the Grinch?

Despite this I have been able to capture the odd FUNCube-1(AO73) pass and have nearly reached 1000 telemetry packets.

It came as a pleasant surprise was finding out I was mentioned in the January issue of Practical Wireless magazine. Tim Kirby (G4VXE) reported on my ISS SSTV capture and APRS experiments. Tim  the magazines VHF/UHF editor has his own blog and is someone I converse with on twitter (@G4VXE)

I realised I didn't blog my SSTV capture back in October, but did post it on twitter feed (@nerdsville)
Here is a scan of my mention and the picture.. I can forgive Tim misspelling my name, it happens a lot! It also seems I might get mentioned in the February issue to following my ICube-1 reception report.

From Practical Wireless - January 2014 Issue

From Practical Wireless - January 2014 Issue

Saturday, 30 November 2013

ICUBE-1 Reception Reports Needed

I have been messaging with Dr Khurram Khurshid the manager of the ICube-1 team and they are struggling a little

 ".. we received icube for a couple of days using FunCube / HumSat TLE's but not anymore we are looking for our own TLE's but haven't been able to track icube for the past few days"

They may officially ask for assistance but after unexpectedly making the first signal report back on the 21st November, I thought I was just ask if anyone could keep an ear out.

ICube-1 was released as part of the UNISAT-5 payload and if still functional is in CW mode on 145.947MHz and the message is "First Cubesat of Pakistan"

Some info/links

I have done an analysis of my first capture

 The ICube-1 facebook page

Thanks Andrew M6GTG

Tuesday, 26 November 2013

I'm famous! and ICube-1, MOVE and Velox-PII telemetry decodes

My confirmation of ICube-1 successful deployment was featured on the AMSAT-UK website on Sunday.

Screenshot of the Amsat-UK webpage
My very quick and patchy decode of the CW beacon was sufficient to identify and verify ICube-1 but I had only been able to decode the words ***ISTAN and CUBESAT. For my own pride I wanted to decode more of the CW message "iCUBE-1 First CubeSat of Pakistan"

I had the IQ file from SDR# so could process it as much as I needed and have used a couple of Morse/CW decoder tools before, but find the free ones often struggle with the faint Doppler shifting CW, just a little too much noise and not enough signal.

Audible decoding isn't an option (yet) but I can visually decode, but the signal going up the waterfall shows the dots and dashes but is too quick for me, and ideally I would like it horizontal rather than vertically.

Then I remembered I had installed Spectravue a few years ago, Spectravue is a powerful spectral analysis/receiver program primarily for use with SDR devices, it was the program used to calibrate my first FUNCube Dongle.

Spectravue is able to take the IQ file and play it back at varying speeds, it can demodulate signals and importantly allows pausing of the playback and easy access to the section of interest, something SDR# is sadly lacking, also it allows a horizontal waterfall display and the ability to save images.

I set about processing and decoding and as you can see from the screenshots below, I managed to identify most of the message (the letters have been added later) The FUNcube-1 telemetry signal can be seen at the top of the images, along with some QRM.

Partial decode of ICube-1 CW beacon

Partial decode of ICube-1 CW beacon

During the process I also spotted two further signals from Velox-PII (145.980 MHz) and the First-Move Cubesat (145.970 MHz) - both of these were recorded in the first decent pass over the UK after deployment  (10:21 on 21 November 2013) the incorrect time shown on the bottom of the screen shots comes from the fact the files processed were copies and the file time stamp had been altered in the process.

I can only wonder when the first reception reports were made? Then again I shouldn't be greedy, one first-to-report is probably enough ;-)

Velox-PII Telemetry/CW beacon

First-Move Telemetry and partial ICube-1
VELOX-PII is the first Singapore picosatellite to operate in low-earth orbit, and was developed under the Nanyang Technological University’s Undergraduate Satellite Program. Details here including how to read the telemetry message.

FIRST-MOVE built by students at the Technical University of München. MOVE stands for München Orbital Verification Experiment. Details here

Thursday, 21 November 2013

Did I make ICube-1's first signal report?

Just like a excited child at the moment! Why you ask? 

Well this morning saw the launch of the numerous satellites from the Dnepr rocket including Funcube-1, and this morning saw the first passes over the UK. Like many others I eagerly sat in front of my computer awaiting the chance to decode the telemetry. However I was doing it remotely using a VNC connection as I was in work...

Sure enough at 10:21 the pass started and a nice strong signal appeared on the waterfall and the FUNCube dashboard sprang to life. I managed 29 packets on the first pass!

The upload ranking at the FUNcube data warehouse

However I noticed another CW signal further up the spectrum which seemed to be on the edge of the FUNCube transponder allocation (145.950MHz) I went to twitter and asked if FUNCube-1 was transmitting a CW beacon? Peter 2E0SQL thought it might be another satellite.

I had captured the pass as an IQ file, and set about trying to decode the CW. I had several attempt using fl-digi remotely but chasing a fast moving doppler on a laggy remote connection wasn't good but I seemed to repeatedly get ***ISTAN.

On the next pass the same thing happened, this time I got the word CUBESAT several times..

The signal had the same doppler shift as FUNCube-1 so was from the same launch constellation and a quick check and I spotted ICube-1 the first cubesat launched by Institute of Space Technology in Pakistan.. which was listed as broadcasting on 145.947MHz using AFSK.

It must be.. ***ISTAN... CUBESAT.... So I sent them a message on their Facebook page and they confirmed that at this stage of the mission they were indeed supposedly broadcasting a CW beacon and what I decoded was part of the message!

Khurram project manager of ICube-1 said "Thanx Andrew ... your message was a great relief for us"

and on their facebook page 
First Signal has been received from ICUBE-1 in UK ... Alhamdulillah the ICUBE-1 mission is successful ... Congrats everyone. Satellite will pass over IST around 9:30 pm today

So it seems lowly M6GTG may have made the first signal report confirming Pakistan's first successful cubesat deployment!

I am grinning madly at the moment!

Wednesday, 20 November 2013

November Satellite Madness!

I haven't done any satellite tracking of late, however this month sees 37 satellites being launched carrying amateur radio payloads. Yes 37!!

Yesterday three cubesats Pico Dragon, ArduSat-1 and ArduSat-2 were jettisoned from the ISS using the JEM Small Satellite Orbital Deployer (J-SSOD), a fourth TechEdSat-3p was released this morning.

Today also saw the launch of Minotaur-1 from NASA's Wallops Island containing 29 satellites, 12 of which are amateur payloads, they have all been deployed.

Tomorrow sees the Yasny Dnepr launch carrying 31 satellites, of which 21 use amateur radio allocations, including FUNCube-1.

Get along to the FUNCube website for further information and to download the handbook and the dashboard telemetry application, after all this is what those FUNCube dongles were designed for!

For up to date information check out the Amsat-UK website, and here is a handy link for a full list of payloads and frequencies

 photo 71dca420-14bc-4c88-9bd2-1ac043cc785e_zpsad07389a.jpg

Thursday, 14 November 2013

NERD-1 development prototype

The NERD-1 HAB development prototype has been coming on in leaps and bounds. The first stage was to take the breadboard transmitter layout and construct a veroboard 'shield'  the transmitter module plugs into some sockets and the addition of an enable control allows me to turn it off and on. What cannot be seen on the photo below is a dual-colour LED to indicate the fix status of the GPS.

Veroboard shield with transmitter fitted
I am still waiting for delivery of the uBlox GPS module/breakout board which is on a slow boat from China, but in the meantime I have purchased a number of other breakout boards (pictured below) to evaluate potential additions and to generally experiment.

Top-Bottom, SD Card module, RTC/EEPROM module and GY-80 IMU
These include a SD Card module, which will be used to log flight telemetry via the SPI interface. The board on the right is a Real Time Clock (RTC) including a button cell and some EEPROM memory accessed and controlled via the I2C/Wire interface. This really isn't needed but was literally a couple of £s.

The smaller board at the bottom is the really interesting one! It is a GY-80 IMU clone, containing a three-axis gyroscope, three-axis accelerometer, three-axis magnetic sensor and a temperature and pressure sensor, again all accessed simply via the I2C interface. Popular in aeronautical RC and personal UAV projects such as Quadcopters it seemed worthy of some experimentation.

All the devices were purchased from Etang Electronics on eBay and was impressed as it all arrived the day after ordering.

I am using the only proper serial port for the GPS data and  I wanted some method of getting debugging and instrumentation from the device during testing. I could have constructed a software serial port but I had an unused LCD character display so decided to connect it up (won't be included on a proper payload!)

It looks nice and is 'cool' however the backlight LEDs do draw an awful lot of current so have been disconnected since the picture was taken.

LCD Character display
At the moment the whole thing is a little messy, but is functional and sits in it's own foam lined box!

The prototype connected up (still no GPS module)
The software development has been pretty straightforward, I am no stranger to the use of I2C and SPI in my day job and there are plenty of software libraries and guides available. Once I have perfected the software and settled on the final design then I am planning on constructing a veroboard flight prototype with all the unnecessary parts removed.

I have also yet to investigate another transmitter unit I have purchased.  

Friday, 8 November 2013

NERD-1 HAB Development begins!

The prospect of developing a High Altitude Balloon payload doesn't fill me with dread, after all "embedded software engineer" is my day job. It is a varied job including PC, Linux and other programming but it is mostly microcontrollers and associated electronics.

What did fill me with dread was the prospect of going out and getting some development kit! I like to switch off from work when I get home so I have never duplicated a development set up at home to resist the temptation to carry on working. So how was I going to go about this on a small budget?

The obvious solution was to use one of the educational and hobbyist systems like the RaspberryPI, Arduino, Propeller or BeagleBoards which have become increasingly popular. I hadn't kept abreast of any of them but after examining the work of HAB enthusiasts and some very rudimentary research I decided to try one out and the cheapest was the Arduino route.

So a quick trip off to eBay and I got hold of an 'Funduino' (an Arduino UNO clone) board for £9 and ordered a uBlox GPS module/breakout board from China (which is still to arrive) as well as a couple of radio modules including the Radiometrix NTX-2 used in many HAB flights.

We call me impressed, after installing the Arduino development system I had the board flashing an LED within 30 seconds! When I was learning electronics and computing back in the early 1980s at school I would have killed for a platform like this!

I took the liberty of downloading Steve Smith's (G0TDJ) ProjectHAB VAYU ino file as a starting point. This ino or 'sketch' file is Arduino terminology for a project. They may be called 'sketches' but rarely has any of my software ever been called a work of art!

This iteration of VAYU uses the RFM22B radio module controlled by SPI, whereas the NTX-2 is much simpler to control using a digital output and a few resistors. There are many handy guides on the UKHAS Wiki

The GPS data will be coming in serially on the UART the same as VAYU so it was trivial to make the modifications and remove the SPI control to get a barebones flight computer running. I was able to breadboard the NTX-2 and had it successfully transmitting from my lounge floor. It even passed its first environmental test of having one of my dogs lick the circuit board while powered up!

UNO and breadboarded NTX-2
The RTTY transmission being received in another room.
However the current payload might be a bit heavy even for a large latex.
The Payload!

The blue mouse shaped device on the left hand of the laptop is an old Haicom HI-204 GPS module which I have had kicking around for years. It is actually a serial device which once powered up starts outputting NMEA data at 4800 baud, this model has an intergrated serial-usb adapter.

When not running the Arduino IDE the UNO board appears as a standard serial port on the PC and can accept or output data, so all I needed to do was route the serial data from one port to another.

I of course made more work for myself by deciding to taking the open source SharpGPS C# based windows program and customising it. As well as decoding it can now forward the data and NMEA sentences from a GPS device on one port to another serial port. It can now log the raw data and play back logs to emulate a device for testing.

The nice thing is this program informs me of the location data, fix status and information about satellites and if and when I iron out some of the remaining bugs and quirks it will make a nice utility which I will make available. Here are some screenshots of it in action.

Now to the next stage....

Wednesday, 6 November 2013

SKARS HAB Presentation

Since my last update I have joined the South Kesteven Amateur Radio Society (SKARS) The society are looking at possible balloon launches as part of the Gravity Fields Festival 2014 In a rash moment I offered to give a talk and demonstration of HAB and HAB tracking for other members.

So last week I nervously turned up with my laptop and some kit. I had created a Power Point presentation to hopefully explain the whole concept. It was an introduction to HAB, the types of payload and balloons how they work, how operators track the flights and the UKHAS and its HabHub system.     

To demonstrate the use of the DL-FLDIGI decoding software I had a few SDR recordings which I could play back. I also wanted to show how you could use a conventional receiver so I created a 'demo payload' in a plastic lunch box.

It consisted of a simple PMR446 radio in VOX mode, connected to a MP3 player which was playing back a recording of a typical RTTY HAB payload. Steve Smith G0TDJ of ProjectHab was good enough to supply me a 4 minute recording of his VAYU-1 payload made when he was testing it.

I then had a scanner which received the transmission, so being clearly audible I was able to plug a lead into the headphone socket and the microphone input on the laptop to show the decoding.

I also demonstated some SDR recordings being decoded which illustrated the QRM, signal fading and drifting and some of the modes in use (RTTY/DominoEx). I also had videos showing the in action (also posted on here).

Despite being apprehensive I actually quite enjoyed giving the talk and hopefully those that attended were entertained and found it informative.

Since then I have took the plunge and ordered a couple of transmitter modules including a Radiometrix NTX-2, an Arduino UNO development board and a uBlox GPS module so can start developing my own payload. So hopefully if I am asked by anyone else to give a talk I can show a live demo!

Friday, 18 October 2013

My APRS broadcasts received by the ISS

This evening I managed to successfully send some APRS messages to the International Space Station that were successfully digirepeated. It might not be a major technical achievement but after monitoring and decoding many passes in the past to now actually send something myself 300 miles up to something traveling at 5 miles/second left me feeling a little chuffed!

I screen capped the evidence from the website which documents Amateur Radio data digipeated by the ISS. In order to appear on the page, a position report in a valid APRS format must be received and then digipeated through the ISS system, then be heard by an internet gateway station, which then forwards it on to the APRS Internet System.

Okay it sounds a bit more impressive when put like that ;-)

The map showing received stations, M6GTG is me!
The detail of my report
List of stations with time stamps, showing me!
List of digirepeated messages
The equipment I used was very similar to that I used for the APRS IGate setup last month.

It consists of a small embedded PC running embedded XP, the sound card output was connected to the microphone input of my Baofeng UV-5R+ operating in VOX mode set to 145.825MHz. The radio was connected through my power/SWR meter in to the X-50 antenna. I used the UV-5R+ instead of the UV-3R since it has a little more power and better audio. I had a SWR of around 1:1.2 and outputting 4W.

The software I used was UISS from ON6MNU and the AGWPE packet engine. It has taken a little time to work out how to setup UISS into auto-beacon mode and putting in the time of the next decent pass (approx 45 degrees elevation) I set it to broadcast position and text data messages every 30 seconds.

The embedded PC running UISS
UV5R+ in VOX mode on 145.825MHz
The power meter showed 4W output, SWR about 1:1.2

I stood out in the dark, hoping to see the ISS pass over but the cloud cover was too thick and monitored using a handheld scanner. I heard my transmissions obviously and the ISS broadcasts as it repeated received messages, but I didn't know if any were mine till I got back to the PC.

Thursday, 3 October 2013


Well this a shameless plug for Steve Smith (G0TDJ) and his new ProjectHAB website/blog.

I met Steve last month at the International UKHAS 2013 Conference and he is embarking on his own journey into stratosphere and is busy building and programming his own payload. Steve had an exciting introduction into HAB tracking when he preformed an impromptu recovery of  Chris Stubbs (M6EDF) CHEAPO4 payload.

Steve with Chris Stubbs’s CHEAPO Pico balloon and payload after recovery

On a related note last night I attended a meeting of SKARS who themselves are looking at possible balloon projects for Gravity Fields Festival 2014

Tuesday, 1 October 2013

First reception of DANDE satellite

The US SpaceX company successfully launched a new upgraded version of its Falcon 9 rocket from California’s Vandenberg Air Force Base. The vehicle, carrying the Canadian Cassiope research satellite, lifted off at 16:00 UTC on Sunday, September 2013.

In addition to the main payload two satellites, DANDE and CUSat, carrying amateur radio payloads were also launched into orbit, both satellites have been reported as functional and transmitting away. Last night I had an attempt at receiving DANDE.

From Amsat-uk
DANDE stands for “Drag and Atmospheric Neutral Density Explorer.” Measuring drag and neutral particles in the lower atmosphere between 325-400 kilometers, DANDE will be measuring real time density, quantifying variations in altitude and over time, as well as providing in-situ model calibration data. The satellite is a low-cost density, wind, and composition measuring instruments that will provide data for the calibration and validation of operational models and improve our understanding of the thermosphere. Weighing approximately 45 kg, DANDE is classified as a nano-satellite that is about 18 inches in diameter.

The Colorado Space Grant Consortium (COSGC) has housed the project for approximately 7 years, in which about 150 students have been a part of the project through initial concept and design, to the current team of mission operators. There are two instruments on board which allow DANDE to make in-situ measurements rather than being passive or only carrying accelerometers. The subsystem ACC (Accelerometers) contains 6 accelerometer heads arranged in a circle which were built in-house. The NMS subsystem (Neutral Mass Spectrometer) also known as Wind and Temperature Spectrometer will survey the variety and quantity of numerous neutral particles in the Thermosphere. This data will be particularly interesting during periods of high
solar activity do to atmospheric effects seen at these times in the polar regions of Earth.

DANDE Telemetry System Information:
Beacon Downlink Frequency: 436.75 MHz FM
Callsign: dandecosgc
Data Rate: 9600 baud
Modulation: FSK
Transmit Interval: every 15 seconds
RF Power Output: 0.75 W
Antenna Polarization: linear

DANDE Beacon Portal
Bruce Davis Project Dande Blog
Using the most up to date TLE (from here) I worked out there was a nice late evening pass, so got out my homebrewed yagi, I posted a picture of it on my twitter account @nerdsville

I did manage to get a signal, but it was very weak so no chance of even trying to decode it. This wasn't helped when a connector on the coax fell apart a few minutes before the start of the pass and I was estimating where to point the antenna. I am a bit out of practice!

Below is a snapshot of the waterfall, I have highlighted the faint beacon bursts.

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 my station statistics can be seen here

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



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 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.