Brief catch-up - October 2022

Another big gap with no updates! 😖

Moving seems a remote opportunity at the current time and so I have decided to 'hang fire' for the time being and see how things develop over the next few months.

I am still operating FT modes when possible; there's usually a chance to do something most days of the week.

I really should think of some new project, radiowise, for the Winter months!

HF bands are behaving extremely well at the moment, with some good DX stations being worked with my standard 5W and lof dipole antennas.

Seems ages since I last posted anything in this blog.

I am very much in a state of 'limbo' as I wait to see if I can realise my dream of moving to be nearer the coast; something I've been trying for a couple of years now.

It's difficult to get your mind into anything other than very simple projects when you don't have a sense of permanency about where you live; at least that's how I feel about it! 😁

FT operation is somerhing that I can do whenever I feel like it - conditions permitting - and it can often result in some surprising results.

I recently managed to work into Taiwan for the first time and today's bag was an interesting mix - bands restricted to 20m and 15m only.

I could see that my signals were going out OK in virtually all directions of the compass - bar into Africa, which is usual -  and I was reading stations from those countries; but it was a struggle to get going and make contact.

Once the 'invisible barrier' was down, I worked an eclectic mix from Guernsey through to South Korea!

Please click the image to see it full size. 😄

Magic Band QSOs

1st MULTIHOP QSO WITH USA - UPDATE!

Almost to the day, one month later, and I make my first multihop contact with the USA! 😊

The band had started well into Europe and I had made a good number of QSOs into Europe. I then noticed that some of the W and K stations being worked form Europe were themselves appearing in WSJT-X and on Gridtracker.

I sorted Gridtracker on the strongest signals and watched as a number of US stations started to climb nearer the top of the window.

I called several, but with no success; but then one did respond and it was all over in the wink of an eye!

I found out subsequently that I had worked a well known 'super station', but - even so - I did it with my 5W and in room dipole.

He didn't acknowledge my electronic QSL, but no matter; I know it happened and it made me Whoop!! 😆

Click images for full size!

Here - as at 5th June 2022 - is a map showing the total number of 'Magic Band' 6m stations worked using my FT817ND and FT8 digital mode.

My dipole antenna faces ENE-WSW but as it is inside my flat - concrete and metal construction, like being inside a Faraday cage 😀 - signals can appear to come from anywhere, and I guess radiate in a similarly random manner.

Still; it all makes for some good fun and hasn't stopped me from getting some good DX on the Magic Band.

I even had a multihop 'spot' in North America. Pity I wasn't able to convert it to a QSO!

Excellent conditions into Japan

Another excellent lift to Japan over the 26th and 27th April 2022. A nice spread of contacts over the islands. Of the stations worked, 3 actually called me and at one point, I was working a station in Japan with another one calling me and a Kuwaiti station calling me too! 😁

Communcation was digital mode - FT4 and FT8 - on 15m and all with 5 Watts only into indoor dipoles!

Please click the image to see it full size.

Contesting Results

Click certificates to see bigger size.

 

 

 

A plug for my local 70cm FM repeater - GB3TD

GB3TD is my 'local' 70cm band analogue FM voice repeater. With the 23 year 'sabbatical' I had away from the hobby, I found that even repeater operations had changed somewhat over the period.

In the late 1980s and early to mid 1990s, stations on the 2m analogue FM repeaters were usually 'wall to wall' and the etiquette was to call "break please" in order to either enter the fray or call a station with whom you had perhaps arranged a 'sked'.

If I were to have jumped straight from 1990 to 2022; depending on the time I made the 'leap', I might quickly have made the obvious assumption that FM repeaters were no longer in use!

Some days, whilst out walking for several hours, I can access a mixture of 2m and 70cm repeaters - including GB3TD - and raise ... no-one.

GB3TD was recently switched to channel UR63, with an input frequency of 430.7875 MHz and an output of 438.3875 MHz. It has a CTCSS access tone of 118.8 Hz. This channel is shared with only 1 other repeater in the UK - in Wolverhampton - so GB3TD benefits from having no issues with potential signal overlap.

This is the "HeyWhatsThat" visual panorama for the repeater. I've made a guess at the antenna height above ground and used 20 metres.

I have worked into GB3TD from over 85 miles distant - on Exmoor - using 5W and a handheld HB9CV antenna and, quite recently, heard a station putting in a good signal from Southampton.

The repeater sensitivity appears to have improved further with the frequency change so it is hoped that even more 'DX' will be heard and for those - like me - who like to walk extensively, it 'holds' my 1 Watt signal nearly 100% of the time on walks of several miles and at distances around 17 miles!

Click on the image to see it full size! 😉

An additional, and often well used, feature of the repeater is Echolink; enabling stations not within RF reach of the site to be able to access GB3TD via the mobile 'phone network and Internet or directly via the Internet.

Click on the "Ridgeway Repeater Group" link in the Useful Links section to the right to read more about GB3TD and the other RRG repeaters.

KG-STV experimental Slow Scan from ISS - Feb 2022

On the 20th of February 2022 the ISS cross-band repeater rig - Kenwood D710GA - was 're-assigned' to run a digital Slow Scan TV experiment.

ARISS Europe - using the callsign ON4ISS - was uplinking the images from the amateur radio telebridge groundstation in Belgium.

A 1 minute and 40 second transmission was followed by a 1 minute and 20 second break.

KG-STV - a Minimum Shift Keying application designed by JJ0OBZ - was used to transmit a number of images over 5 passes  between 05:10 and 12:00 UTC whilst the ISS was over Europe.

KG-STV sends a 320 x 240 compressed JPEG in 15 lines of 20-off 16 x 16 pixel blocks. 2 frequencies are used ... 1800Hz for the ones and 1200Hz for the zeros. The signal only occupies 600Hz and so is very efficent.

It is possible for the receiving station to send a block repeat request to the transmitting station in order to have it resend missing, or corruped, blocks to produce a 100% image but unfortunately this would not be possible with this test.

My images were from the 08:31Z and 10:08Z - the two highest altitude passes. The 87 degree pass produced the better of the 2 images, but both are marred by missing and corrupted data.

 

  

 

 Passion SSTV - an amateur radio group in France - kindly created a certificate for the occasion!

 

 

 Click on the image to see it full size! 😉

 

Hopefully there will be more tests in the future!

Zachtek 80To10 200mW WSPR transmitter

After having a play with WSPR using WSJT-X, and after reading a glowing review of Zachtek's 80To10 model WSPR transmitter, I decided to break the bank and purchase one for myself! 😊

It is basically a 200mW, multi band hopping, standalone WSPR beacon transmitter .. that also doubles as a precision signal generator.

I thought it would be ideal to run through my fan dipoles - 40, 20, 15 and 10m - and give me a great picture of conditions across these bands during the course of a day.

A PC is only required for the initial set-up, which is very straightforward. A supplied active GPS antenna picks up a signal for positional and timing purposes and once it has a lock, the transmitter gets on with the business of beaconing on the selected bands.

Current draw is around 100mA at idle and 250mA whilst transmitting, and a phone charger makes a suitable power source, when not running from a PC USB port.

I did have some 'teething troubles' because I was having a combination of low GPS satellite signal strength and potential RFI blocking .. made worse by the poor signal level. After a re-positioning of the antenna puck, all was working absolutely fine!

All in all, an excellent piece of equipment for accurate and informative propagation studies!

And my thanks to Harry for quickly guiding me to relocate the GPS antenna when I was convinced it was something more serious! 🙂

----------------------------------------------------

Please look at the updates further down the page to follow my progress
with 'fine tuning' and getting things working satisfactorily.

----------------------------------------------------

I now have the Zachtek transmitter working, and beaconing on the 40, 20, 15 and 10m bands.

It cycles from one band to the next and I have a 120 second break after the 4 band cycle before the process starts again.

I'm achieving some astonishing distances, bearing in mind the output power is only 200mW, or 23dBm.

When I've accrued more data, I want to try and see how each of these bands varies, propagation wise, throughout the day.

Here are some 2D plots for each of the bands.

Click on the images to see them full size! 😉

10m

15m

20m

40m

UPDATE! - 4th February 2022

I now have the Zachtek transmitter working standalone and have collected - at the time of writing - around 6 hours of continuous data.

Here is a map - with band key - showing just where I am reaching.

Click on the image to see it full size! 😉

UPDATE! - 8th February 2022

After running in to some issues regarding the transmitter 'freezing' after some 8 to 10 hours of operation, all appears to now be resolved.

I contacted Harry Zachrisson at Zachtek and appraised him of what was occurring.

After a protracted period of running the transmitter, it would just cease beaconing. The first time it happened I was able to get it to restart by removing the charger connection, plugging it back into my laptop and running the configuration software. I could see it polling the ‘visible’ satellites and then getting a positional lock.

To me, it seemed as if the device was perhaps drifting and losing the GPS position/timing signal. Harry suggested it was far more likely that the GPS antenna was picking up RFI and that, combined with the fact that I was receiving only a very weak satellite signal anyway, was the cause of the failed beaconing.

I relocated the GPS head and used double sided tape to secure it to the window glass. Then I powered up the transmitter and monitored it during a 12 hour plus period; it worked fine! 

Panic over.  😃

The following screen shot shows reporters that have picked up my transmissions during the course of 12 hours over the 8th February 2022.

Click on the image to see it full size! 😉

WSPR - Weak Signal Propagation Reporter

Joe Taylor - the Nobel Prize winning amateur radio enthusiast who developed WSJT-x - devised WSPR in 2008.

It is another machine to machine application that uses low power transmissions to determine propagation paths.

It uses a 6Hz wide FSK signal to send callsign, grid locator and signal strength (dBm).

Each frame is 120 seconds long, of which 110.6 seconds is transmission.

There is nominally a 5:1 receive:transmit ratio.

I have been using the built-in WSPR transmitter/receiver in WSJT-X.

The best reception to date on 20m was a 10mW signal from Italy! 😊

I've included a map of WSPR reporters picking up my 20m band signals where I've been using my FT817ND, running 500mW.

The longest distance reports were in Queensland and New South Wales - 10,372 miles and 10,696 miles respectively.

Click on the images to see them full size!  😉

UPDATE! - 8th February 2022

After running in to some issues regarding the transmitter 'freezing' after some 8 to 10 hours of operation, all appears to now be resolved.

I contacted Harry Zachrisson at Zachtek and appraised him of what was occurring.

After a protracted period of running the transmitter, it would just cease beaconing. The first time it happened I was able to get it to restart by removing the charger connection, plugging it back into my laptop and running the configuration software. I could see it polling the ‘visible’ satellites and then getting a positional lock.

To me, it seemed as if the device was perhaps drifting and losing the GPS position/timing signal. Harry suggested it was far more likely that the GPS antenna was picking up RFI and that, combined with the fact that I was receiving only a very weak satellite signal anyway, was the cause of the failed beaconing.

I relocated the GPS head and used double sided tape to secure it to the window glass. Then I powered up the transmitter and monitored it during a 12 hour plus period; it worked fine! 

Panic over.  😃

UPDATE! - 4th February 2022

I now have the Zachtek transmitter working standalone and have collected - at the time of writing - around 6 hours of continuous data.

Here is a map - with band key - showing just where I am reaching.

Click on the image to see it full size! 😉

UPDATE! - 3rd February 2022

I now have the Zachtek transmitter working, and beaconing on the 40, 20, 15 and 10m bands.

It cycles from one band to the next and I have a 120 second break after the 4 band cycle before the process starts again.

I'm achieving some astonishing distances, bearing in mind the output power is only 200mW, or 23dBm.

When I've accrued more data, I want to try and see how each of these bands varies, propagation wise, throughout the day.

Here are some 2D plots for each of the bands.

Click on the images to see them full size! 😉

10m

15m

20m

40m

Decoding RDS (Radio Data System) from FM broadcast stations

This is another good use for the low cost RTL-SDR type of software defined radio equipment.

There is only one additional piece of software required, and that is:

SodiraSDR Software Radio by Bernd Reiser

Radio Data System, or 'RDS', is a communications protocol standard for embedding small amounts of digital information in conventional FM radio broadcasts.

It creates a standard format for a variety of information including time, station identification and program information.

It uses an error correcting method with a data speed of 1.1875 kb/s on a 57kHz subcarrier of the FM radio broadcast signal -  88-108 MHz range in the UK.

It is very easy to set up; the extracted folders and files can be placed wherever you like on your PC and only require a copy of the ExtIO_RTL2832.dll file for your RTL-SDR device being placed in the top level folder.

The software does a whole lot more than receive FM and decode RDS, and will work with Digital Radio Mondiale, or 'DRM' digital modes, AM and SSB too.

Unlike some of the other SDR projects I have played with, I found that I needed a relatively strong signal to see the RDS decoding. A typical FM stereo broadcast signal will have +/- 75kHz deviation and 15kHz audio response. That occupies 180kHz bandwidth. When you add the RDS signal, it extends it even further. I found a filter setting of 190kHz best.

Here are a couple of screenshots for the main waterfall window and the RDS decode window:

 Click on the images to see them full size! 😉

BARTG RTTY Sprint Contest - Jan 22/23 2022

I hadn't given my SCC callsign - G2B - an airing on digital modes for quite some time and so decided I would have a go at the BARTG RTTY Sprint contest on the HF bands over the weekend of January 22nd and 23rd 2022.

I can't imagine many radio operators who sit cross legged on the floor and use their rig(s) and a laptop computer perched precariously on a cardboard box ... but then it takes all sorts! 😆

I started at the competition kick-off time - 12 noon on the Saturday - and continued until about 6 p.m. The I rose early on the Sunday and was back on again at around 5 a.m.

This turned out to be a bit of wishful thinking as things didn't really get underway - for me at least - until about 6:45 a.m. and I was wishing I had perhaps been better in having a lie-in! 😴

Most of my activity was with European stations, but I did manage to make it into North America on 4 occasions and - out of the blue - Uruguay!

The set-up is very simple ... FT817ND and fldigi; that's all. I used 40, 20 and 15 metre bands and indoor dipoles.

I always have a bit of fun and games when it comes to uploading the logfile. I haven't invested in any additional software so make do with what fldigi can provide in the way of a Cabrillo file, and then make any amendments in Excel and Notepad.

 

  Click on the image to see it full size! 😉

 

Little piece about QRP HF working in RadCom

Recently a new gentleman - Daimon Tilley/G4USI - took over the role of putting together the 'HF' column in RadCom magazine.

I thought I'd like to share - as I try to as often as possible - just how well it is possible to make contacts using low power and a compromised antenna set-up.

I find this works best with the digital modes - including machine generated ones - but it's also feasible with voice communications too.

 Click on the images to see them full size! 😉

 

 

 

ADS-B - Decoding and displaying aircraft tracking data

I've been interested, for a long time, in watching the various websites showing aircraft data in real time, but not got around to doing it directly with an SDR, relevant applications and a suitable antenna.

After investigating what programmes were available for the Windows environment, I chose:

• RTL1090
  
  RTL1090 is a non tunable 1090 MHz receiver application for Mode-A/C or Mode-S transmissions.
  
  Mode A equipment transmits an identifying code only.
  Mode C equipment enables the air traffic controller see the aircraft altitude or flight level automatically.
  Mode S equipment has altitude capability and also permits data exchange.
  
  ADS-B (Automatic Dependent Surveillance Broadcast) is a technique that relies on aircraft or airport vehicles broadcasting their identity, position and other information derived from on board systems (GNSS etc.)
  
  This signal can be captured for surveillance purposes on the ground (ADS-B Out) or on board other aircraft in order to facilitate airborne traffic situational awareness, spacing, separation and self-separation (ADS-B In).
  
  
• Virtual Radar Server
  
  Virtual Radar Server is an open-source .NET application that runs a local web server.
  
  You can connect to the web server with any up to date browser and see the aircraft plotted on a map.

After configurations, these applications receive the local ADB-S 'S' mode transmissions and show aircraft details as a map overlay. The end effect is virtually identical to the web based and mobile 'phone based views, except for not needing an Internet connection and only being able to see a limited number of aircraft dependent on the antenna gain and location.

With an internal HB9CV - cut for 70 cm ! - I was still able to see plots up to around 40 miles distance:

Click on the image to see it full size! 😉

Decoding telemetry data from satellites 🚀

Here, to date, are the screen shots of the decoded telemetry data that I've been able to receive from a small range of satellites.

• CAS-9/XW-3/HO-113 was launched from the Taiyuan Satellite Launch Centre in China.

It carries a CW telemetry beacon, GMSK telemetry data transmission, V/U mode linear transponder for SSB and CW, a visible light band space camera and an experimental thermoelectric generator for high school students.

It took several attempts to obtain a strong enough signal for decodable data; an 84 degree pass finally produced the necessary results. 😊

The decoded data I received was as follows: 

 Click on the images to see them full size! 😉 

There may be an issue with with SWR - note the forward and reflected power levels which give a calculated figure of about 5.5:1.

• The Bobcat-1 satellite was developed at the Ohio University Avionics Engineering Centre and launched on October 2nd 2020 and deployed into orbit from the ISS on November 5, 2020.

It is a 3U cubesat deployed to study Global Navigation Satellite Systems (GNSS). As implied, the global network includes Europe’s Galileo, the USA’s NAVSTAR GPS system, Russia’s GLONASS and China’s BeiDou Navigation Satellite System. Studies will hopefully improve the availability and performance of these navigation systems for other satellites and spacecraft.

It will probably de-orbit sometime early in 2022.

 

• The KSU-Cubesat (King Saud University Cubesat) is a 1U cubesat which was developed by students and researchers of the College of Engineering at King Saud University, Saudi Arabia.
  
  It was launched on March 22nd 2021 from Kazakhstan and takes photographs of the Earth, moon and space and sends the images to the College ground station.

• JAISAT-1 (Joint Academy for Intelligent Satellites for Amateur Radio of Thailand) - a 3U cubesat - was launched on July 5th 2019.  It is Thailand's first amateur radio satellite.
  
  The JAISAT-1 Beacon signal is on 435.700 MHz in GMSK Mobitex 4800 bps and it carries an amateur radio 2m to 70 cm linear transponder for SSB and CW communications.

ARISS SSTV 'Lunar Exploration' Awards - Dec 2021 Event!

For the ARISS SSTV December 26th to 31st 2021 event from the International Space Station; there were a whole host of award certificates.

Here are the award certificates from a whole range of groups; all of whom obviously take a great deal of effort in producing such excellent works of art!

Click on the images to see them full size! 😉

The one above is a bit different in that it is awarded for gaining
5 certificates from a requisite awards list!