VK5JST VHF Aerial Analyser (2015)

My recently completed 2015 version of the VK5JST Aerial Analyser

This week in amateur radio I finally put the finishing touches on my 2015 VK5JST (Jim) VHF Aerial Analyser.

Originally I purchased this kit from Adelaide Hills Amateur Radio Society (AHARS) in 2015. But life and work got in the way and I have taken this long to get around to putting it together.

This kit featured in the December 2015 edition of the Australian AR Magazine.

The kit was easy to assemble, setup and test using Jim’s instructions. All parts were included with clear instructions and diagrams. Here is a scan of the instructions that came with my kit:

The AA works very well and will be a mainstay in my kit for years to come.

A new improved version of the AA from Jim is now available for a very modest price including shipping – see the link below.

For those just starting out in the hobby, this bit of kit is an excellent way to get started in electronics with a project that will prove to be a very useful tool for building and testing antennas. Even with limited skills in soldering etc, if you have a good soldering iron, take your time and follow Jim’s instructions, you will have no issues.


AllStarLink Recording Script

Here are some details on setting up an automated recording system for AllStar Link nodes. The ground work for this has been done in app_rpt, but this script will assist in publishing the recordings making them more accessible.

The original script was from Joshua Nolton (KG5EBI) – Self Proclaimed Engineer on youtube.

Joshua’s post is here: https://dvswitch.groups.io/g/allstarlink/topic/recording_your_qso_s_as_an/32389801

I have modified his script to not cut off any currently recording transmissions and also to sort the recordings in to day, month and year.

The script can be added to cron to automate everything.

Firstly watch and follow the instructions in the above video, using the modified script below instead. Note that my script location and name may be different to the ones used in the video and you also need to install lsof.

You need to do the following:

  • enable recording in rpt.conf
  • create the script using the code below and put it in a suitable location – I just use /var/log/asterisk/recording/encodepost.sh as the location and name.
  • change the script file to allow it to execute (chmod u+x)

You will need to install the following:

  • apache2 – to serve up the files.
  • lsof – for checking if a recording is being accessed.
  • ffmpeg – for conversion of the audio files to mp3 to save space.
  • rsync – for copying the files around.

Bash Script:


#This script can be safely added to cron to run every minute. It will not copy and convert the currently recording file as it checks to see if each .WAV is in use by using lsof.

#Required programs:
#lsof, rsync, ffmpeg. i.e. run "apt install lsof rsync ffmpeg"

#Set your node number here:

cd /var/log/asterisk/recording/$node
for i in *.WAV;
        do name=`echo "$i" | cut -d'.' -f1`
        echo "$name"
                if [ -z "$(lsof "$name".WAV)" ]
                                ffmpeg -i "$i" -codec:a libmp3lame -filter:a loudnorm -qscale:a 2 "${name}.mp3"
                                mkdir -p "/var/www/html/library/`date -d now +%Y`/`date -d now +%m - %B`/`date -d now +%d - %A`"
                                rsync -avP ./"$name".mp3 "/var/www/html/library/`date -d now +%Y`/`date -d now +%m - %B`/`date -d now +%d - %A`"
                                rm ./"$name".*
                                rm *.txt
                                sleep 1


Your root crontab can have the following added to automate the whole process. Of course change the script location and name as required. This will run the script every minute.

* * * * * /var/log/asterisk/recording/encodepost.sh