APRS
APRS and rabbit warrens

APRS and rabbit warrens

Have had APRS in Subie and with the HT for a while. VHF has limited use out in the bush due to lack of coverage but HF (30m) has potential. Anyway that aside I was intrigued by references to “Ham Radio of Things (HRoT)”.

The value is having a view as to local activity, not just positions of cars but the extended weather, CFA warnings, email and messaging abilities dictated setup of a node beyond aprs.fi. Still want to develop a node and sent weather conditions but before we get to that I’ve decided to setup a node at home which lead down this path.

Ended up with XASTIR on a Pi with VHF and HF inputs.

Setup on RaspberryPi 4 which is mounted onto the back of a 10″ screen. Using remote desktop this setup supports the the radio providing an display for APRS and Digital modes. The base setup is Raspbian Buster (Debian) then running KM4ACK-Pi excellent ‘Build-A-Pi’ script to install the ham tools.

The TS590, a COVID acquisition, has built in USB audio interface. Also has a RS232 interface. Both the USB and RS232 CAT interfaces are active so can control the device from two computers. In this case the USB interface is used for is connected to Pi and used by Flrig whilst the RS232 via a USB converter connected to the iMac and used for logging with MacLoggerDX.

Keen to setup a APRS node. This will have iNet and RF access. The weather and fire alerts from XWSRV-AU are welcome giving a good overview as to activity in my area. Not from my home but here is a view of activity taken whilst I was in down Snobs Creek (behind Eldon) showing a fire near home;

Using Direwolf in I can exploit both 2m via the TM-v71 and 30m via the TS590. Direwolf HF config;

ADEVICE plughw:3,0 
 CHANNEL 0
 MYCALL VK3ARH
 MODEM 300
 AGWPORT 8000
 KISSPORT 8001
 INTERNET GATEWAY
 IGSERVER aunz.aprs2.net
 IGLOGIN VK3ARH 123456

and VHF being ;

ADEVICE  plughw:2,0
 CHANNEL 0
 MYCALL VK3ARH
 MODEM 1200
 AGWPORT 8000
 KISSPORT 8001
 INTERNET GATEWAY
 IGSERVER aunz.aprs2.net
 IGLOGIN VK3ARH 123456

Where then differences being hardware port and modem speed. The two audio interfaces being the TS590 and the ZLP MiniProSC. Both use the Burr-Brown from TI chip and preform very well. No issues with being identified or used on Linux.

allen@Lethe:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: b1 [bcm2835 HDMI 1], device 0: bcm2835 HDMI 1 [bcm2835 HDMI 1]
Subdevices: 4/4
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
card 1: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones [bcm2835 Headphones]
Subdevices: 4/4
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
card 2: CODEC [USB audio CODEC], device 0: USB Audio [USB Audio]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 3: CODEC_1 [USB Audio CODEC], device 0: USB Audio [USB Audio]
Subdevices: 1/1

Audio from the as too high and was receiving error messaged in Direwolf. This was addressed by resetting the alas system to defaults

sudo /etc/init.d/alsa-utils reset

Whilst I count not work either station as 40 sucked, here is VK3OAK and VK2VRO out activating;

So in short, XASTIR works as described. Have not got custom maps as yet otherwise an excellent piece of software and Direwolf works very well. I have purchased a MFJ-1270x TNC however still not deployed as not behaving whilst Direwolf with audio worked as described and solid.