Allstar linked 900 MHz repeater with self contained Mini-ITX Linux PC

Interior of Allstar linked 900 MHz repeater -- Mini-ITX controller on 2U shelf

Entire low-power 900 MHz reperater on 2U shelf -- with Beaglebone Black (rev.C) controller

Another low-power 900 MHz reperater on 2U shelf -- with Raspberry Pi-2 controller

Simplex MicroNode for 900 MHz with RTCM and TK-941

Simplex Node for 900 MHz with Beaglebone Black and TK-981

Allstar web transceiver with Beaglebone Black

Allstar dual server - dual node web transceivers (built for N7GLV)

K5TRA homebrew four repeater controller & linker (built for WD5EMS)

K5TRA homebrew USB radio interface (1.8" x 2.5")

K5TRA homebrew 5V regulator & fan control (1.8" x 2.5")

Simplex Node for 900 MHz with Beaglebone Black and TK-931 (for WB0BMY)

Map of 900 MHz Allstar linked network

Allstar Repeater Linking

During the past several years I have been migrating my internet linking from EchoLink to Allstar. The 927_TECH hub server is still maintained and linked into the Allstar 900 MHz network; but, the EchoLink side has become secondary. Allstar is an implementation of asterisk, an open source PBX that runs on Linux. The Linux platform can provide complete multiport repeater controller functionality, thereby eliminating the need for a controller board! The most recent repeaters that I have built do not have hardware controller boards in them. I have built three with mini-ITX Celeron boards. The results have been very good. Allstar has a range of codecs available (depending on available BW). Linked and repeated audio is superb. More recently, a number of the 900 MHz group has been building with "Beaglebone Black" and "Raspberry Pi-2" ARM processor boards. Results have been so good with both the BBB and RPi-2 boards that I think it's safe to say this is the future direction for all of us. If I can help with information, please feel free to contact me.

There are two Allstar distribution variants: XIPAR and ACID. I use the ACID implementation; so, my comments here will be along those lines. ACID originally was implemented in a CentOS distro and more recently in Debian (Jessie, 8.2). This release is called DIAL.

The Allstar web site to get started is: . On that site you will find much information as well as the ability to register with Allstar. Once registered, you can request server and node authorization.

You will also find acid-sysadmin helpful.

A server is a PC platform running Allstar asterisk on the Linux operating system. One or more nodes can be associated with each server.

A node is connection entity running on a server. Usually nodes are each connected to a radio or repeater; however, a node can be defined as a HUB node. HUB nodes don't have radio hardware directly connected. Hardware nodes can be simplex, duplex, or voter types.

Radio equipment is interfaced to the server PC in either of two basic ways: 1) a USB interface, or 2) a network (UDP) interface.

In the first case, the radio or repeater is interfaced to a USB plug-in through a URI (USB Radio Interface) such as the product sold by DMK: , or the RIM (Radio Interface Module) on the Repeater Builder web: . I have also made my own USB interface: K5TRA USB-radio interface. USB sound FOBs can also be modified to make an interface. For more information, see: . Since the radio or repeater is connected via USB to the Server PC, they must be in the same location.

In the second case, a network connection bridges the radio or repeater to server. The server PC can be in a different location. The interfacing hardware here is the RTCM (Radio Thin Client Module) sold by Micro-Node: .

A comprehensive source of information is

Some important Linux directories:
/etc/asterisk     This directory contains the configuration files for Allstar on your PC.
/usr/local/sbin     This directory contains the Linux shell scripts for Allstar.
/var/lib/asterisk     This directory contains a current database of all active Allstar nodes: rpt_extnodes.
/usr/src/astsrc/asterisk     This directory contains subdirectories with source code.
/var/log/asterisk     This directory contains logfiles such as messages (errors and warnings).

Key configuration files for Allstar (in /etc/asterisk):
rpt.conf     This file defines all operational settings for your node (or nodes) on this server.
iax.conf     This file sets Allstar port association and preferred codec order.
extensions.conf     This file sets routing of incoming connections to the correct nodes.
simpleusb.conf     This file defines low CPU overhead USB radio interface (requires a COS control line).
simpleusb_tune_usb.conf     This file defines audio levels for TX and RX associated with simpleusb.
usbradio.conf     This file defines high CPU overhead USB radio interface (requires discriminator audio).
voter.conf     This file defines RTCM (Radio Thin Client Module) interface.

Either simpleusb or usbradio is used (not both) for USB radio interfaces and sound FOBs. Alternatively, voter is used when radios are interfaced with an RTCM.

Click on above *.conf files for annotated example files.

If you are planning to run the (WA3DSP) Archlinux implementation of the Beaglebone Black or Raspberry Pi2, check out:

N4IRS has ported the ACID implementation to Debian (8.2) Jessie. This is a more current Linux distro than CentOS and works well with newer PC boards. A bootable installation image can be downloaded from: The root password is debian.

Some LINUX setup information to remember:
     If you run a CentOS or Debian distribution:
     /root/.bashrc     add alias shortcuts
     /etc/ssh/sshd_config     edit SSH port setting, then type:service sshd reload to restart SSH service
     Date and time setting; type:    date - -set= "2 OCT 2014 18:00:00"     to set date and time
     Timezone setting: The file /etc/localtime controls the system timezone.
                          It is a symlink to one of the files in /usr/share/zoneinfo
                          FIND /yourzone/subzone (for example: /America/Chicago)
                          cp  /etc/localtime  /etc/localtime-old
                          ln  -sf  /usr/share/zoneinfo/yourzone/subzone  /etc/localtime

     If you run Archlinux distribution (from WA3DSP image):
     /root/.bash_profile     add alias shortcuts
     /etc/ssh/sshd_config     edit SSH port setting,then reboot BBB to restart SSH service
     type:  timedatectl  for time and date info
     type:  timedatectl  set-time "2012-10-30 18:17:16"  to set date and time
     Timezone setting: The file /etc/localtime controls the system timezone.
                          It is a symlink to one of the files in /usr/share/zoneinfo
                          FIND /yourzone/subzone (for example: /America/Chicago)
                          type:  timedatectl  set-timezone yourzone/subzone  to set date and time

     Add your allstar shell scripts in /usr/local/sbin  (chmod 751)

     Some important source code files: *.c , especially apps/app_rpt.c and channels/chan_*.c

     A good vi editor reference: Basic vi Commands .


Radio Linking with Allstar

AllstarLink provides hams with a means of connecting radios (repeaters or simplex links) over the internet. It is built upon the asterisk open source PBX (runs on Linux). If a router is used, UDP ports (your choice, usually 4569) must be open to pass packets. TX & RX audio and control signals (PTT & COS) are sent. Audio quality is better than EchoLink or IRLP.