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.
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.
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:
#!/bin/bash
#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:
node=42688
cd /var/log/asterisk/recording/$node
for i in *.WAV;
do name=`echo "$i" | cut -d'.' -f1`
echo "$name"
if [ -z "$(lsof "$name".WAV)" ]
then
ffmpeg -i "$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
else
sleep 1
fi
done
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.
This week I have setup a windows VM on my server to run RMS Trimode fro the Winlink network. This setup is running for several HF bands. Details can be seen here.
About 12 months ago (2018) I decommissioned my FreeNAS based file server in preference of a Synology DS918+. While this device has been fantastic, and I do recommend it, it’s a bit boring and not fitting my theme of DIY and putting retro hardware to good use.
The main considerations for this build are:
Ability to run virtual machines.
As much retro hardware that makes sense.
Low power draw.
Reliable and very long lasting hardware.
CPU performance and feature set that will future proof this build for FreeNAS.
RAM upgrade capacity.
Plenty of physical drive capacity in the case that is easy to access.
So here is a sneak peak of the project while I wait for the remainder of the parts to arrive.
Parts List
Intel Xeon L5640 CPU @ 2.27GHz, 6 Core HT with 12MB Cache, 60W (2010)
Super Micro X8STi Motherboard (~2010)
Fractal Design Define R6 in White with Glass Side
48GB RAM
Corsair RM550x PSU
Cooler Master H411 Cooler
2x 30GB SSD for OS (ZFS RAID1)
3x 250GB SSD for VMs (ZFS RAIDZ1)
4x 2TB HDD for Storage (ZFS RAIDZ2)
Continuing the retro theme, all the working parts are second hand and out dated from their usual intended purpose. Although in this build the parts are still reliability new, this is for power consumption, performance and reliability and also for certain feature sets on the CPU.
The board was chosen because it was relatively cheap to purchase with a CPU included. The CPU for its instruction set and very low power consumption. New PSU to help protect the nice hardware. Drives because they will be carried over from my old NAS. The Case for style, to show off the hardware, drive capacity (more than 10x 3.5″) and overall quality. And lastly the Cooler as they are quiet and long lasting.
The first PC projects for the site. The aim is to setup a Dual Slot 1 Celeron as a router. I’m not sure if the performance will be enough for my 50Mb VDSL connection, so will have to wait and see.
The Slot 1 Celeron does require some modification to work with SMP (Symmetric Multi- Processing). CPU Central have details on this modification here.
The plan is to try and run OPNsense on the machine and use it as a gateway/firewall for my VDSL connection. Failing that, Windows NT and some retro gaming!
All the retro parts will be wrapped in a nice new case from Corsair and powered by a Corsair Rm550x (overkill, but I wanted a quality PSU to protect the hardware).
Back in the day I used to own a Leadtek Winfast GeForce2 Pro. This, at the time, wasn’t a bad 3D card for the PC. The cooling solution on this card wasn’t fantastic and soon failed.
Using whatever I had laying around at the time I had a solution. Basic, crude and dodgy, but worked very well for about 12 months until I upgraded the card to a GeForce4 Ti 4200 8x. The cooler used was a Silver Orb, a great CPU cooler at the time.
The VK6 Hub now has a bridge to DMR on the Brandmeister network.
Node 42716 is bridged to Brandmeister Talk Group 505005. This node is generally connected into 42732 (the VK6 Hub), so you can talk to all the folks on that network via DMR.
The News Hub can be listened to by using a VoIP client (such as X-Lite on a Mac or PC or Groundwire on a smartphone). This will allow you to listen from any device that has VoIP client. To connect:
User ID: 42719
Domain: vk6-hub.vk6rx.net:5077
Password: VK6News!
Disable the “Register with Domain…” or similar as this is not required.
Once connected simply dial 42719 and select 1 for the live loop or 2 to start the playback from the start.
Please hangup when not in use to help save bandwidth.
Got given a 36V solar panel a few weeks ago by a friend. Not much use for a 12V system, so I set about rewiring it.
Originally it was three 12V arrays in series. I’ve split the middle array in two and given half to each of the remaining 12V arrays. Paralleled them both up for 18V.
Sealed it all up. Perfect!
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