NCRG IRLP system

The IRLP project is an example of new technology where a closed network of Amateur repeaters are linked together with linux servers using a Voice on IP application. IRLP is a project that started back in 2000 when an interest was taken in connecting the Internet and Amateur Radio using a program and interface that Dave Cameron VE7LTD had come up with and made available to Amateur operators around the world.

At that stage there was no IRLP nodes anywhere in Australia and James VK6FJA built an IRLP node in early 2001 for the Northern Corridor Radio Group and got it on air using a 56K mode dialup connection in February of the same year. Unknown to the NCRG, Peter VK2YX also had commenced building a node in Sydney and before too long there was node 6100 and node 6000 on air (at this stage there were only "50" nodes worldwide!). This was the best thing in Amateur Radio since the old JOTA Aussat linkup back in the early 1990's. Assistance provided by Greg (now VK5JGW), Gavin VK6HGR, Trevor VK6HTW, Richard VK6HRC, Bill VK6YW and others have improved the project to where it is today. IRLP Node 6100 links the VK6RNC 2m repeater (and soon VK6RNS 70cm repeater) into a worldwide network of amateur repeaters via the Internet.

In order to run an IRLP node, some form of connection to the Internet is necessary. In Australia, Internet access has been quite expensive for the last few years and large bandwidth applications like VoIP have been limited until recently. IRLP Node 6100 started on a 56K dialup connection and then with the support of Bill VK6YW at EON Technology, was able to be moved to a better 24x7 Internet connection where 64Kbit/s was not going to be a limitation and bandwidth was available. Without EON Technology, the NCRG would not have been able to have node 6100 on air for as long as it has been! More recently with another location change the IRLP node sits on a Bigpond Cable connection with the use of a Netcomm NB3100c router - but with the new NCRG club rooms being completed, it is hoped to house the IRLP equipment on-site and feed the Internet to it via a 2.4GHz wireless LAN link.

(Click for a full size image)

This was the original plan - the DxCluster part has not been implemented, but will be incorporated into the new design.

Here are some more pictures of the IRLP Node 6100 as it has been built, rebuilt and moved over time........


The original IRLP PC /\	The first 56K modem Internet connection and router /\	Still under construction in a new rack on wheels /\	Almost completed before putting it in the new rack /\

The completed rack with a new power supply and UPS. /\	Temporary testing from a power cupboard with a high speed Internet connection for a few weeks. /\	The completed rack installed at Eon Technology. /\	Greg (VK5JGW) assembling RJ45 connectors. /\

A temporary Icom radio whilst the FM92 got repaired - and an upgrade of software on the bench /\.	The new rack in the old position at Eon Technology. /\	VK6FJA on the roof assembling the antenna coax during a maintenance visit with VK6HGR and VK6HRC. /\	The completed antenna on the building rooftop. /\

HARDWARE:

The VK6RNC IRLP project is designed to link to 146.625MHz 2m repeater in Perth into a worldwide network of repeaters by using an interface circuit designed by Dave Cameron VE7LTD and the Internet. The system has been running continuously since 28 February 2001. The hardware is listed below:

-FM92 A band radio (local) with CTCSS PCB.

-Pager filter (modified VHF duplexer)

-APC UPS 240v with monitoring

-20A Switchmode Power Supply

-38Ah battery backup

ROUTER Computer Specifications:
- 486 SX - 25 MHz processor
- 16Mb RAM (72pin)
- 3c509 LAN card
- Intel LAN card
- Floppy disk boot

IRLP Computer Specifications:
-Celeron 400MHz processor
- 64Mb RAM
- CDROM-R/W
-SoundBlaster Card – CT1600 16 bit
-10baseT ethernet card – 3C509B PnP
-40Gb hard disk
-2Mb S3
-1 Parallel port 0x378 irq 7

This is a recent picture of node 6100 (2004) at it's second location at Eon Technology.

The PC runs linux (Currently Kernel 2.4.28 – from a RedHat 9 CD) and is configured with the hardware devices shown above.

The software running is the IRLP software designed by David Cameron VE7LTD and also F5MZN’s DxNet (currently inactive - Version 4.3b). Also OpenSSH has been installed for secure logins and the kernel ax25 set up for running KISS mode on a conventional TNC.

Scripts have been installed to announce the current weather in Perth and also the Time. A daily task runs to email the system administrator a performance check report as well as provide details of the mains power from the UPS.

The IRLP controller is basically a standard irlp control board design by Dave VE7LTD, but with further CTCSS and audio modifications, so that control of the radio remotely can be maintained. A (future) separate audio link from the DxCluster UHF radio will be fed to the DTMF controller so that a ‘RESET’ and ‘over-ride’ facility for the main VHF radio can be implemented.