TSGARC AR Roadshows

Folks today I secured agreement from Waitrose Chipping Sodbury to host our first AR roadshow. Idea is for us to showcase some technology but more importantly raise awarenss of AR to the local community. This is supurb location, great footfell at weekends and will be part of the Yate and Chipping Sodbury Festival during June.

At this stage I am keen to recruit some willling volunteers to help me do this. Tea, coffee and I am told cake will be provided but don’t hold me to that. Also want some ideas on the equipment to showcase but remember must be easy to set up and take down and be compact enough not to cause any undue health or safety concerns. Also want a visual presence and a audible one too e.g. GB3 WR on loop!! Want to attract as many people as I can.

Anyone with any ideas please catch me at club or post them here. Actual dates for the event will follow and Gary can add it to out programme. I will also send them to RADCOM.

Many thanks

Mark  2E0RKM

 

 

TSGARC embark on ARDF….or do they?

Folks an entertaining and very interesting talk from Graham G4DPH last week.  Given that Graham and fellow Weston Club members have invited TSGARC to their next club ARDF event perhaps we could consider a club based RDF project or system which we might take on location with us!! Count me in (Peter 2E0UAR) and hopefully others now the weather has improved? Peter already has a number of antenna designs which we could develop from.  I have to say the whole notion appeals to me as it brings together portable (which in effect I am currently), outdoors, (potentially dog walking although that was not mentioned) and radio. Could even add Geocaching if you like to that list. However I would not want to be the fox!!!

My thanks to Graham for his time and fascinating array of home made equipment together with numerous stories of eventing which kept us on the edge of our seats. TSGARC (well me at least) will now definitely be considering an ARDF section of its own.

A few useful websites I came across (but to be honest there are so many links);

http://www.topbanddf.org.uk/index.htm

www.qsl.net/w1dmm/marc/howto/foxhunt/gnvrdf.pdf

www.dxzone.com/…/Operating_Modes/Radio_Direction_Finding

 

Food for thought Folks!!

Mark 2E0RKM

 

Tracking High Altitude Balloons using SDR

After the talk last night I took a moment to mention my friend Sam Sully, who is running a club at Monmouth School to launch 8 High Altitude Balloon’s (HAB) into the upper atmosphere. The club is involving 42 students from the ages of 12-18 who have been working in teams to build payloads for their balloons.

Payload

The payloads used by the club are based around a Raspberry Pi Zero single board computer, Raspberry Pi Camera V2Radiometrix UHF transmitters (each payload on a different frequency between 434.0MHz and 434.8MHz) and GPS Module. The raspberry pi is responsible for getting the location of the balloon from the GPS and sending the coordinates over the radio using the RTTY protocol.

Receiving Setup

There are a few ways of receiving the radio down-link from the balloons. The easiest method for radio amateurs is to use either a 70cm radio with a computer interface or a software defined radio, such as an RTLSDR dongle which many of the club members already have.

In terms of antennas, the clear line of sight provides a relatively easy job. For a tracking vehicle a standard mag-mount 70cm mobile antenna will be sufficient, or even a 1/4 wave ground plane ghetto mounted to the roof of your car! For a base station a high gain 70cm yagi would be more suitable to get better range and pick up the balloon from lower altitudes.

A simple ground plane antenna made from some stripped-back RG-117 strengthened with straws. Works a treat!

An 868MHz antenna built from welding rods and 25mm^2 trunking (this was used for experimental 2-way comms with the balloon and not for tracking)

Software Used

In order to decode the packets from the balloon, the following software is required:

  • SDR# – The first piece of software that I used is called SDR# (SDR-Sharp). It is used to control a SDR dongle, and tune into the frequency transmitted by the balloon payliads. A full guide to installing and setting up the software can be found in one of my previous posts. Download Link
  • VB-Cable – This is a virtual audio cable, used to send the audio from SDR# to the packet decoding software. Download Link
  • DL-FLDIGI – This is the software that decodes the RTTY packets. Download Link

Software Setup

First of all you need to download and install SDR#. Clear instructions on how to do this are provided here

Then you need to set up VB-Cable to send the audio output of SDR# to the RTTY Decoder.

  • Download VB-Cable from the above linkVB-Cable Download
  • Extract the .zip file
  • Run “VBCABLE_Setup_x64.exe” as an administrator (don’t use x64 version if you are using 32bit windows)Running as admin
  • Click on “Install Driver”Install Driver
  • Accept the unverified driver warningUnverified Driver Warning
  • Restart when prompted
  • Go into the sound settings (right click on volume icon, click “sound”)Sound Settings
  • Click on “CABLE Input”, and click on “Set Default”

Now that the virtual audio cable is setup, you will need to is set up SDR#. Tune the radio to the frequency of the payload you plan to receive (these will be posted at a later date), and set the mode to USB. You can adjust the squelch control but that is not required. Set the bandwidth to around 10khz.

Now, your SDR# window should look something like this (except tuned into the 70cm band):

SDR# Windows

Finally, open dl-fldigi (HAB Mode), which decodes the RTTY packets.

You will need to do several things:

  • Select the appropriate audio input (“Virtual Audio Cable” or “CABLE Input“)
  • Move the red markers until they are overlapping the two RTTY signals. After you have done this once the software will automatically track the signals.
  • Select “Op Mode” from the toolbar at the top, then hover over “RTTY” and click “Custom

In this window you must alter these settings:

Carrier Shift => Custom

Custom Shift => 450

Baud Rate => 75

Bits per character => 8 (ascii)

Parity => none

Stop bits => 2

A window showing the RTTY Configuration

RTTY Settings

Now go into the “Configure” menu and setup your callsign. This will be displayed on tracker.habhub.org with every upload you submit.

Now the software is setup you should now see text on your screen. dl-fldigi parses this data and uploads it to habhub. Well done you are now contributing to the tracking!

DL-FLDIGI Readout

DL-FLDIGI Readout

 

Tracking a balloon

Now that you are picking up telemetry, the habhub tracker will predict the flight path and landing site for the balloon. The chase vehicles will try and get to the landing site to recover the balloon. Please note this is not as easy as it sounds and takes some practice! Laptops are essential and a minimum of two people per vehicle is recommended.

Conclusion

I hope this is an informative article and perhaps enlightens some of you to the world of high altitude ballooning. Please check out https://ukhas.org.uk/ which will have some better instructions on it to help get you set up. If you are having issues don’t hesitate to comment below or send me an email.

Hopefully we’ll see some of you at the launch next weekend! I’ll let everyone know on Wednesday which day we’ll be launching.

-Peter Barnes (2E0UAR)

(edit: i’m sorry everyone I clearly can’t spell balloon)

Commonwealth CW Contest from TSGARC Shack Saturday 11th March 2017

The commonweath contest is one of the longest running contests on HF.
http://www.rsgbcc.org/hf/rules/2017/rberu.shtml
TSGARC will be sending CW this Saturday as part of the commonwealth contest organised by the RSGB. We will be testing a directional 80m loop as darkness approaches on Saturday evening. All welcome to attend and help or take part. Organised by John M0HFH and Rex G4RAE.

No Longer SWL!

Hi All

Just to advise having just passed the Foundation exam I have secured the call sign M6TJV. RSGB and QRZ sites updated.

Thanks to all of you for your help, the Intermediate RSGB book has arrived so onwards..

Terry M6TJV

 

Noise Floor vis a vis Coax Standards

Folks

Whilst resting after a hard and rather wet days walking in West Wales (thankfully we dodged the snow) thought I would check in on the Amateur Radio Facebook page. Came across this rather interesting article which made me feel somewhat vindicated that I have chosen a better quality coax for what will be my new shack and qth location.

Why even good antennas need good Coax cable Bonito Newsroom

Hoping to be at club next Weds work permitting.

Mark

2E0RKM

WiFi updating at the Club Shack

Over the holiday period a small group of us managed to update the WiFi connection to the club shack as was planned in the programme. It was all hands to the pumps and led by Garry and Paul we were also well oiled by regular cups of Tea and a few mince pies (allegedly as I didn’t see any of them,!!). The on-going good working relationship we have with the chantry meant we were given complete access to all areas so that we could scope and route cabling where we need to and facilitate a better more secure network.

I am sure Garry or Paul will update us in due course as to the current status of the new link and its capability (not my area) but Andrew and I had fun working at hight with the facility of my truck (seems he did all the hard work though).

Much fun

2E0RKM